What is happening here? Opinions? - Page 3 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #61 of 116 Old 12-18-2012, 08:58 PM
AVS Special Member
 
smokarz's Avatar
 
Join Date: Feb 2007
Location: Hartford, CT USA
Posts: 3,261
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 63
Quote:
Originally Posted by curttard View Post

Yeah, I have to admit I don't get why asking DIYers to provide any measurements is "totally unrealistic". This is an enthusiast forum. Don't most of us have at least an EyeOne, for example? If not, why are people who haven't even bothered to calibrate their projectors worried about the imagined difference they would perceive with a screen that has .1 more gain?
Don't all the DIYers in the audio subforums provide frequency charts etc for their projects?


Some do, some don't. And I do understand that not everyone have the necessary resources or know how to run measurements.

But one thing that is certain, and a must in DIY audio, is that all designers/creators provide various type of measurements so the DIY community know exactly what they're looking at.
smokarz is offline  
Sponsored Links
Advertisement
 
post #62 of 116 Old 12-18-2012, 09:12 PM
AVS Special Member
 
curttard's Avatar
 
Join Date: Aug 2005
Posts: 1,320
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Liked: 27
Quote:
Originally Posted by prof55 View Post

How many dollars worth of instrumentation would be necessary to provide the screen measurements that you and others here consider necessary?
(I'm assuming these would include on and off-axis gain (i.e. viewing cone) and color accuracy, but let me know if this is not the case)

I don't know what others consider necessary. For myself, if I am being told one screen is brighter than another, I would like to get an idea of "how much brighter". And even my LT can do that, as I said.

Also able to do that: a photo of each, under-exposed a bit so the whites don't clip, taken with the exact same camera settings; maybe even with a "control shot" with the lamp in High (or Low if the other shots are in High) to show how much variation lamp mode provides, for comparison.

Of course, anyone who doesn't want to spend the money on ANY amount of equipment can send samples to those who have it and are willing to test -- but this depends on the person being willing to accept the results.
curttard is online now  
post #63 of 116 Old 12-18-2012, 09:23 PM
AVS Special Member
 
smokarz's Avatar
 
Join Date: Feb 2007
Location: Hartford, CT USA
Posts: 3,261
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 63
Quote:
Originally Posted by prof55 View Post

No, I don't think most screen DIY'ers own calibration equipment. In audio, a five dollar microphone and a freeware RTA program will supply all the specs you care to post. I'm guessing that video calibration equipment is a bit more pricey... What does the system you mention cost?


This is incorrect.

Most DIY speaker designers use a calibrated mic system. Typically, it's the Dayton Audio OmniMic V2 Precision Measurement System ($300).

However, not everyone have that kinda of cash to spare. The typical DIYer would at least get a Dayton EMM-6 mic ($50), or a Behringer ECM8000 mic ($60). Add in the cost of a powered USB amp and mic stand, and your final cost for a decent mic setup is around $100.

Yes, there are free program to run measurements in DIY audio, just like in DIY video.

When put side by side, the investment in tools is not that very far apart (a little less on audio), but it still ain't $5.
smokarz is offline  
post #64 of 116 Old 12-18-2012, 09:57 PM
AVS Special Member
 
smokarz's Avatar
 
Join Date: Feb 2007
Location: Hartford, CT USA
Posts: 3,261
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 63
Quote:
Originally Posted by Kirnak View Post

No offense Cuttard, but that i1 LT is basically useless if it hasn't been profiled with a spectraphotometer like the i1 Pro pretty recently. Perhaps it has? If you want to send it to me, I'd be happy to profile it for you with my i1 Pro.
OK, I'm very firmly in the "scientific measurement" crowd. That's why I included measurements in my recent screen build thread. But that doesn't mean that I can't use help from the "intuition" crowd. I had a question about spraying my screen and MM was there to give a bit of advice. I learned an awful lot about building a screen from MM and PB-Maxxx, and continue to be grateful for the help I received. I learned a lot about measurements elsewhere, and I am very grateful for that help as well. We've got several groups of people who spend a lot of time helping others, and it's a damn shame they don't get along better. I really don't claim to know who's fault that is, if it's anybody's, and to be honest I don't care.
If you want to steer someone towards a paint with some scientific analysis behind it, do so when they ask for help. I don't think there's anything wrong with posting your own measurements and experience in such a thread. Just be prepared to back up your measurements and to spend the time the OP needs helping him. If you're not prepared to help him, you should hold your peace. Even if you think the "intuition crowd's" plan is bad, remember a bad plan is better than no plan. (I'm not claiming anyone's plan is bad, just being hypothetical.)
Again, suppose some paint is just the worst paint ever. So what? Paint over it. Even if the original paint is pure crap, how much will the hobbyist learn painting that first screen? Enough so they can go on, learn even more about what is best for them, and give it another go.
I just don't anyone is helped by confrontation and rudeness, on either side. There's an easy solution: start a thread explaining why people should use a paint that has been analyzed. Then it's your thread and you can get your point out without stepping on someone else's thread. If you want to analyze all of the popular screen paints and post your data, I see nothing wrong with that. Just be forewarned, it's a lot of work.


I would have agreed with you if we were talking about a $20 OTS paint. But if the recommended solution required you to mix 6-8 paint ingredients, and cost up to $100 to put together, then this doesn't apply. With that many ingredients in the mixes, you have much higher possibilities of messing up your paint solution, and I haven seen that happened to folks. Add $50 for sprayer, and additional cost for a proper mask to protect yourself from paint particles floating around the room. And the effort to prep your room, covered up your furniture, etc.

I don't know about you, but if I am spending over a $100 difference, I like to see a little more than just words. I be damn pissed if my $150+ investment doesn't come out as advertised and I have to paint over it.
smokarz is offline  
post #65 of 116 Old 12-18-2012, 10:04 PM
Advanced Member
 
Kirnak's Avatar
 
Join Date: Nov 2009
Posts: 822
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
Quote:
Originally Posted by curttard View Post

Mine is probably pretty off by now, I remember reading they drift over time and this one is more than four years old now. Can profiling still work, and is this a profile that can be used with HCFR? I appreciate the offer!

No worries! Profiling works great as long as the two PJs are similar technology. What kind of PJ do you have? Assuming it's an LCD, I can profile it with HCFR against my pro. I'll send you the meter back and email you the HCFR file. The easiest way to do it is just save the calibration session I profile with. Then make a copy o the session, open it and do your calibrating. Keep the LT in a sealed ziploc bag with a fresh desicant, that way the profile will last. i1 LTs drift pretty rapidly if they're not kept sealed and bone dry. As in a week or two and it's no longer accurate. Keep it in the ziploc and replace the desicant every time you open it and it should hold for up to a year.

Re-chargeable desicants are available on Amazon pretty cheap. When you're ready, PM me and I'll PM you my address. Send me the meter with return postage and I can turn your meter around in an evening or two--if I'm home. When I hit the road I can be gone for a couple of weeks though...


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.




To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



[URL=http://
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Kirnak is offline  
post #66 of 116 Old 12-19-2012, 06:25 AM
Moderator
 
prof55's Avatar
 
Join Date: Oct 2002
Posts: 1,412
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by smokarz View Post

This is incorrect.
Most DIY speaker designers use a calibrated mic system. Typically, it's the Dayton Audio OmniMic V2 Precision Measurement System ($300).
However, not everyone have that kinda of cash to spare. The typical DIYer would at least get a Dayton EMM-6 mic ($50), or a Behringer ECM8000 mic ($60). Add in the cost of a powered USB amp and mic stand, and your final cost for a decent mic setup is around $100.
Yes, there are free program to run measurements in DIY audio, just like in DIY video.
When put side by side, the investment in tools is not that very far apart (a little less on audio), but it still ain't $5.

While I'm sure many do use a calibrated mic, I'll guarantee there are many "specs" posted that used a $5 cheapie. wink.gif My point was that it's a LOT easier to generate "specs" in audio than in video.

Audio notwithstanding, here's my question to you, smokarz:

What measurements do you personally desire, and what specific instrumentation would be necessary to provide those specs?
prof55 is offline  
post #67 of 116 Old 12-19-2012, 07:11 AM
AVS Special Member
 
smokarz's Avatar
 
Join Date: Feb 2007
Location: Hartford, CT USA
Posts: 3,261
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 63
Quote:
Originally Posted by prof55 View Post

While I'm sure many do use a calibrated mic, I'll guarantee there are many "specs" posted that used a $5 cheapie. wink.gif My point was that it's a LOT easier to generate "specs" in audio than in video.
Audio notwithstanding, here's my question to you, smokarz:
What measurements do you personally desire, and what specific instrumentation would be necessary to provide those specs?


First, let me make it clear, I am not asking every DIYer to post measurements. It is unrealistic.

I am only asking this from the 'designer', so the collective DIY community has a better understanding of the advertised products around here.

Often, the words contrast, gain, black, whites, are thrown around here like they were pulled out of thin air.

Personally, I like to see some data on Gain, RGB, and xzY. As for the instruments used, that's up to the designer to decide. I believe these measurements would provide excellent data for the DIYers in helping them decide if the screen is the right choice for their applications. Gain would tell you how dark or light the screen is. RGB/xzY would tell you if the screen is netural. Is it reflecting exactly what is projected at it, or is it altering the colors.

If these measurements can't be afforded, I think the 'designer' should speak with cautions about his solutions so it does not confuse the general public.
smokarz is offline  
post #68 of 116 Old 12-19-2012, 07:16 AM - Thread Starter
AVS Club Gold
 
MississippiMan's Avatar
 
Join Date: Nov 2002
Location: Byhalia, Mississippi. Waaaay down in the Bottoms
Posts: 14,934
Mentioned: 1 Post(s)
Tagged: 1 Thread(s)
Quoted: 165 Post(s)
Liked: 223
Quote:
Originally Posted by prof55 View Post

........... here's my question to you, smokarz:
What measurements do you personally desire, and what specific instrumentation would be necessary to provide those specs?

And should I bite on a EODIS3 i1Display Pro, will "any" test results that differ even a small percentage from what you...or anyone else of a similar mind find / feel are acceptable... be met with abject criticism even if the Screen itself is found to perform in a exemplary fashion? I'd be willing to bet quite a bit such figures (...and the screen itself...) would be dismissed out of hand anyway.

Really, it seems most all the fooi-fa-rah is about if a screen can improve the levels of contrast as the appear on the Screen (...not as they are "inside the PJ... rolleyes.gif ) Well if the "Eyes" see a difference that's what really matters. Last time i checked, no one has stated a i1Display Pro voiced a vocal complaint that the Movie looked bad.

And this silly debate on what constitutes Hot Spotting. Well, yeah, if you take a Flash shot of dull, gray surface with sub-1.0 gain you'll be hard pressed to see any "warmer" center. Go figure. But if a Gray/Silver screen can achieve 1.3 or more gain without having a true "Hot Spot" (...something that moves with your eye's location...) or a noticeable "Warm Spot" (...something usually only apparent in solid color projected fields...) then couldn't one say that it is offering up something along te way of improved performance where none existed before?

And Surface Color neutrality? The slight differences between what some consider "perfect' and what others offer as being acceptable and advantageous are only considered worthy of argument by those who want to / need to press a point as to how they are not indeed "perfect". Grist for making an argument, that's it.

Essentially, all the above are examples used by those who need the support of Testing to validate their own opinions (...and choices...) as to what is good and proper compared to whatever else is out there that runs even a wee bit contrary to what they consider "perfect".

That is why "Testing" for testing sake alone has been ignored by those who need not depend upon such to be able to offer up worthy DIY Screen applications. It's an expensive proposition whose end results are not at all indicative of being worth the effort, save to "prove' something someone else expects to be proven. Perhaps...no, almost assuredly things would have been different from the start had Testing not be prefaced by acrimony, and then used as a Club to attempt to beat people into submission...or ill repute. But it was...and essentially still is being wielded in a like manner.

To quote James T. Kirk;
"I'm laughing at the superior intellect"
MississippiMan is online now  
post #69 of 116 Old 12-19-2012, 07:30 AM - Thread Starter
AVS Club Gold
 
MississippiMan's Avatar
 
Join Date: Nov 2002
Location: Byhalia, Mississippi. Waaaay down in the Bottoms
Posts: 14,934
Mentioned: 1 Post(s)
Tagged: 1 Thread(s)
Quoted: 165 Post(s)
Liked: 223
Quote:
Originally Posted by smokarz View Post

First, let me make it clear, I am not asking every DIYer to post measurements. It is unrealistic.
I am only asking this from the 'designer', so the collective DIY community has a better understanding of the advertised products around here.

No one "advertises products" on this Forum. Such a statement is both false, misleading, and wholly intentional. It reflects the garbage you've been few elsewhere...and now it's being excreted in the same manner it was before. Your in danger of being lumped in with those who also used false assumptions and statements to try to garner support for their own concept of what DIY Screen making is all about.
Quote:
Often, the words contrast, gain, black, whites, are thrown around here like they were pulled out of thin air.
Personally, I like to see some data on Gain, RGB, and xzY. As for the instruments used, that's up to the designer to decide.
If these measurements can't be afforded, I think the 'designer' should speak with cautions about his solutions so it does not confuse the general public.

The "General Public" are the only ones that matters on this forum, not the "select few" who differ with what the "General Public" is willing to accept and go for because so many of the "General Public" who have gone before them are very happy and satisfied.

For "your" own reasons your on some kind of crusade to prevent the misleading of the "General Public". basically saying over and over that the General Public" is being done a gross disservice by "The Designer". Well we've seen that before, and in no uncertain terms it amounts to a selfish and self-centered way of saying, "Unless things are done as I feel are best done, they hold no validity whatsoever". And be advised, the "General public" is really this Forum's membership, and that is why, as a member, you are bound to look toward their best interests. And in no way, manner or form does yours or anyone else s continued pressing of a essentially moot issue constitute being helpful. No...it's just being repetitiously argumentative.

To quote James T. Kirk;
"I'm laughing at the superior intellect"
MississippiMan is online now  
post #70 of 116 Old 12-19-2012, 07:40 AM
AVS Special Member
 
superleo's Avatar
 
Join Date: Nov 2006
Location: San Antonio, TX - USA
Posts: 2,147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 25 Post(s)
Liked: 215
Even if a paint mix cost is$150 or so, I'm sure that by the time that individual decided to use it, he/she has asked a multitude of question, and I'm sure not only the creator of the mix had answer to those questions. Data on it would be just additional information... first hand experience and input form user is as valuable as any data you can put out there, and there is plenty of that here.

It is with out question that measurements (data) would help, but not a must have, as some of you suggest. Also, DIYers are looking for the "best bang for your buck" for what ever reason, whether they are on a budget or just very frugal with their money, want something inexpensive that would give them good results. I'm sure too, that by the time that person gets to "DIY screen" Forum they well know how much a commercial screen cost., so stating that spending $150 plus another $60 for a sprayer gun pus anything other materials, for something that might not work for the user is ridiculous. By now, the person interested on a DIY screen know what h/she would be getting into and the time and effort involved. Some of you mentioned the risk of the user not getting what is "promised". Well for the investment of time and money even if you compare it to a commercial screen it'll be money well spent even if the first try fails... it'll be a fraction of the cost of a commercial screen.

Also, a very small fraction of users have calibration equipment, either for video or audio, even on this forum, and even if they do, lack the knowledge of how to use it correctly.

I'm very surprised that smokarz, as a DIYer himself, is harsh to other DIYers... I've seen his posts regarding spandex screens, and had included screen shots of the screen and his fame, which I'm sure are very useful to others searching for the same type of screen, however, he mentions the data and type of numbers for the screen, but he has not post a single graph or measurement, if he has I missed it, and I'm not one that need it. Regardless, I don't think data for a paint mix or certain screen is absolutely necessary... The user needs to research, ask questions and decide what is best for him/her... There is plenty of information and people willing to help, we just need to use it in the correct way.

More than agree with Garry, if one needs measurements and scientific data for his/her satisfaction stick to threads that provide that kind of information.

"Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid."

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

superleo is offline  
post #71 of 116 Old 12-19-2012, 07:45 AM
AVS Special Member
 
smokarz's Avatar
 
Join Date: Feb 2007
Location: Hartford, CT USA
Posts: 3,261
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 63
Sir. Let me just ask you one simple question. I won't dance around this topic of measurements and data, because it always circled around endlessly.

In the interest of looking out for the 'general public', and prevent false information provided to them.

How did you measure the gain on your paint? How did you verified it was 1.3, instead of 1.2, or 1.1, or 1.15?

Every benchmarking that was done gain of projector screens required instruments. Every manufacturers that design and sell projector screens for a living used instruments to measured gains.

I, and many on here, would like to understand how you measured gain on your screen paint.
smokarz is offline  
post #72 of 116 Old 12-19-2012, 08:03 AM
AVS Special Member
 
superleo's Avatar
 
Join Date: Nov 2006
Location: San Antonio, TX - USA
Posts: 2,147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 25 Post(s)
Liked: 215
Again, and again and again.

You want a DIY screen to give you comparable data of a commercial screen...

And you ask... many... I would venture so say just a few would like to know how...

Even if is his very subjective experience in comparison to other screens...

At the end.. the information provided does not satisfy your requirements try something else...

You are missing the point, it is a DIY screen.

"Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid."

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

superleo is offline  
post #73 of 116 Old 12-19-2012, 08:28 AM
Moderator
 
prof55's Avatar
 
Join Date: Oct 2002
Posts: 1,412
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by smokarz View Post

First, let me make it clear, I am not asking every DIYer to post measurements. It is unrealistic.
I am only asking this from the 'designer', so the collective DIY community has a better understanding of the advertised products around here.
Often, the words contrast, gain, black, whites, are thrown around here like they were pulled out of thin air.
Personally, I like to see some data on Gain, RGB, and xzY. As for the instruments used, that's up to the designer to decide. I believe these measurements would provide excellent data for the DIYers in helping them decide if the screen is the right choice for their applications. Gain would tell you how dark or light the screen is. RGB/xzY would tell you if the screen is netural. Is it reflecting exactly what is projected at it, or is it altering the colors.
If these measurements can't be afforded, I think the 'designer' should speak with cautions about his solutions so it does not confuse the general public.

Since you did give specific recommendations for audio test gear, I would appreciate the same for video (including approximate costs).

Now, let's take a look at the two specs you desire; gain and color neutrality:

Gain: I'll assume you mean both on and off-axis gain in your request. A single figure, (i.e. 1.5) while it might sound good, wouldn't really tell us a lot. Brighter is better, but if folks on the side see a sharp drop off, the application won't work for everyone. So a single gain figure, while fun for comparison, is basically a bare start. Include viewing cone and it starts becoming more useful. But another issue goes hand in hand with gain: hotspotting. There is no way to provide a specific "number" for hotspotting, but it is readily observed - and quite subjective. Yes, you can take brightness readings at various locations on a screen, but this is not a standardized measurement, and is quite dependent on individual projector performance.

Color: A useful spec, and I assume we can agree that a 6500K screen is the goal. If a screen surface is viewed under direct sunlight, most are able to judge it's neutrality with reasonable accuracy. If it has a tint in any direction most can see it, particularly toward red or green. We're less sensitive to blue, but that's another story. In any event, it doesn't take a rocket scientist (or a spectrophotometer) to determine that a surface is usably neutral. All you really need to do is compare the sample to white house paint in the sunlight, lol.

In a home theater environment, things change. The human eye is remarkable adaptive, and with no frame of reference other than the screen you are viewing, I'm willing to bet that you are unable to distinguish between an image at 5500K and one at 6500K. No, I'm not suggesting that we should disregard this spec entirely, I'm merely pointing out that it is not a sacred as some seem to think, and it is easily checked by the simple comparison suggested above. Further, if a DIY application were to show a pronounced "push" (as some have), it would be immediately spotted by those who try it.

Finally, I doubt the ability or need for the average DIY screen builder to interpret and apply the specs you find so dear. And yes, I feel the same way about audio specs. Figures are great for "bragging rights" in the competitive environment of a forum, but the usefulness and accuracy of DIY measured specifications in either field is actually very limited. The final judgement is ultimately the satisfaction of the eyes and ears of the user, as it should be.


Garry
prof55 is offline  
post #74 of 116 Old 12-19-2012, 08:38 AM
AVS Special Member
 
smokarz's Avatar
 
Join Date: Feb 2007
Location: Hartford, CT USA
Posts: 3,261
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 63
Quote:
Originally Posted by superleo View Post

Even if a paint mix cost is$150 or so, I'm sure that by the time that individual decided to use it, he/she has asked a multitude of question, and I'm sure not only the creator of the mix had answer to those questions. Data on it would be just additional information... first hand experience and input form user is as valuable as any data you can put out there, and there is plenty of that here.
It is with out question that measurements (data) would help, but not a must have, as some of you suggest. Also, DIYers are looking for the "best bang for your buck" for what ever reason, whether they are on a budget or just very frugal with their money, want something inexpensive that would give them good results. I'm sure too, that by the time that person gets to "DIY screen" Forum they well know how much a commercial screen cost., so stating that spending $150 plus another $60 for a sprayer gun pus anything other materials, for something that might not work for the user is ridiculous. By now, the person interested on a DIY screen know what h/she would be getting into and the time and effort involved. Some of you mentioned the risk of the user not getting what is "promised". Well for the investment of time and money even if you compare it to a commercial screen it'll be money well spent even if the first try fails... it'll be a fraction of the cost of a commercial screen.
Also, a very small fraction of users have calibration equipment, either for video or audio, even on this forum, and even if they do, lack the knowledge of how to use it correctly.
I'm very surprised that smokarz, as a DIYer himself, is harsh to other DIYers... I've seen his posts regarding spandex screens, and had included screen shots of the screen and his fame, which I'm sure are very useful to others searching for the same type of screen, however, he mentions the data and type of numbers for the screen, but he has not post a single graph or measurement, if he has I missed it, and I'm not one that need it. Regardless, I don't think data for a paint mix or certain screen is absolutely necessary... The user needs to research, ask questions and decide what is best for him/her... There is plenty of information and people willing to help, we just need to use it in the correct way.
More than agree with Garry, if one needs measurements and scientific data for his/her satisfaction stick to threads that provide that kind of information.



Leo,

I've provided data and measurements on what I can do with my equipments on my spandex build thread. Like most DIYers, I don't have all the tools or know hows to take all kind of measurements. That's why I find it very useful information for folks to have while researching

I agreed with you, folks that look at DIY options generally after 'bang for bucks' performance (beside the pride of building your own projector screen or speakers, etc.),

Some basic data would quickly allow us to eliminate screens that won’t work for us, and leave us with lesser choices to look at. Just like when a person need goes comparison shopping, we look at user reviews, bench marking, specs, etc to help us make better informed decisions about our purchases.

I don’t know if you have been keeping up with prices on manufactured screens, but they are very affordable these days. A very well reviewed Elite screen can be had for roughly $400. If you ask someone to invest in $150-$200 for a DIY screen, I hope the DIY option is a very solid one. Yes, DIY is still cheaper, but it’s no longer just a fraction of the cost of a good commercial screen.

Anyone that tell me a $200 DIY screen beats the crap out of this $400 commercial screen in every aspect of screen performance, better show me some data.
smokarz is offline  
post #75 of 116 Old 12-19-2012, 08:57 AM
AVS Special Member
 
smokarz's Avatar
 
Join Date: Feb 2007
Location: Hartford, CT USA
Posts: 3,261
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 63
Quote:
Originally Posted by prof55 View Post


Finally, I doubt the ability or need for the average DIY screen builder to interpret and apply the specs you find so dear. And yes, I feel the same way about audio specs. Figures are great for "bragging rights" in the competitive environment of a forum, but the usefulness and accuracy of DIY measured specifications in either field is actually very limited. The final judgement is ultimately the satisfaction of the eyes and ears of the user, as it should be.

Garry


I have to disagree. Figures, measurement, and data are not only used for bragging rights. They enabled us to identify flaws in the performance of our systems (both audio and video), and they help us to fine tune our systems so that we can maximize their performances.

Sure the eyes can see that green is way off on their screen, and ears can tell that the bass non existent their subs. So how do we make adjustments? One can use their eyes and ears and manually tweak their systems by trials and erros. Or one can use tools and instruments to help them more efficiently and effectively fine tune their systems to reference (see and hear what the studio intended the user to experience). Is 'Reference' the goal? Of course not. It's the user's personal choice so deviate from it as you pleased.

Fine tuning one's system is a personal choice, as much as a financial choice. But I would have to disagree with those that so quickly dimiss the values of data, measurements, and instruments in the audio and video world.
smokarz is offline  
post #76 of 116 Old 12-19-2012, 09:03 AM
Member
 
johngraz's Avatar
 
Join Date: Jan 2006
Posts: 52
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I just doubt the accuracy of any group of more than 1 DYI'er to properly calibrate and measure and report any set of data. Like screen shots, I think they are useful if properly done, but as soon as you introduce all the variables, and as a comparison tool across individual set-ups, I think think are not as valuable. Audio has a little less room for error, but video has plenty of variables that could skew results. I am not discounting them myself, just not giving them the weight to the be the be all and end all and ultimate arbiter of what is "perfect" For me that is far to subjective to be measured by any device. JMHO:)
johngraz is offline  
post #77 of 116 Old 12-19-2012, 09:03 AM
AVS Special Member
 
superleo's Avatar
 
Join Date: Nov 2006
Location: San Antonio, TX - USA
Posts: 2,147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 25 Post(s)
Liked: 215
smokarz,

Firs, I want to state that I very much respect your opinion and your efforts on providing the most accurate information. I'm very aware that you provided the textual information about your measurements, I hope you believe that I mean this in a good way, but you have not provided the actual data, and I really don't care (in a good way) the descriptions and comments, yours and for others, are for me more than enough, I have no reason to doubt your numbers if that is what you say they are... I know that is me. Other might want the actual process and procedure you used plus the data not just the textual info... once again not me, I have no reason to doubt your numbers. Just as when Maurice (MMan) or anyone else for that matter posts their findings or want to share their experiences... For me, I know I'm repeating my self, the information they provide is more than enough and I can process and discern the contextual or hard data on my own. I don't find anything that MMan has posted as ludicrous or improbable. My experience and common sense would tell me that is probable... up to what extent, well I think will be dependent on many different factors, but that the result would be something that would satisfy those that are willing to try it... once again, I have no reason to state otherwise (unless I tried it).

Cost wise... just me again... even if prices are $400, which are not bad... going DIY its a 100% savings... In my world that is a BIG difference.

"Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid."

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

superleo is offline  
post #78 of 116 Old 12-19-2012, 09:04 AM
AVS Special Member
 
smokarz's Avatar
 
Join Date: Feb 2007
Location: Hartford, CT USA
Posts: 3,261
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 63
Quote:
Originally Posted by superleo View Post

Again, and again and again.
You want a DIY screen to give you comparable data of a commercial screen...
And you ask... many... I would venture so say just a few would like to know how...
Even if is his very subjective experience in comparison to other screens...
At the end.. the information provided does not satisfy your requirements try something else...
You are missing the point, it is a DIY screen.


I really don't undertand how I am missing the point.

One made a claim that his screen has a gain of 1.3, and I like to know how he arrived at that conclusion.

Isn't that a fair ask? I mean really. Even though this is a DIY forum, a number is thrown out there?.
smokarz is offline  
post #79 of 116 Old 12-19-2012, 09:10 AM
AVS Special Member
 
smokarz's Avatar
 
Join Date: Feb 2007
Location: Hartford, CT USA
Posts: 3,261
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 63
Quote:
Originally Posted by superleo View Post

smokarz,
Firs, I want to state that I very much respect your opinion and your efforts on providing the most accurate information. I'm very aware that you provided the textual information about your measurements, I hope you believe that I mean this in a good way, but you have not provided the actual data, and I really don't care (in a good way) the descriptions and comments, yours and for others, are for me more than enough, I have no reason to doubt your numbers if that is what you say they are... I know that is me. Other might want the actual process and procedure you used plus the data not just the textual info... once again not me, I have no reason to doubt your numbers. Just as when Maurice (MMan) or anyone else for that matter posts their findings or want to share their experiences... For me, I know I'm repeating my self, the information they provide is more than enough and I can process and discern the contextual or hard data on my own. I don't find anything that MMan has posted as ludicrous or improbable. My experience and common sense would tell me that is probable... up to what extent, well I think will be dependent on many different factors, but that the result would be something that would satisfy those that are willing to try it... once again, I have no reason to state otherwise (unless I tried it).
Cost wise... just me again... even if prices are $400, which are not bad... going DIY its a 100% savings... In my world that is a BIG difference.


Leo, I posted calibration graphs on my thread. I also, posted ftL measurements in that thread.

If people wanted see a pic of my i1D3 set up in front of the screen, or a pic of my desktop with HCFR running. I can post those pics too, I felt those weren't necessary since I told stated specifically which instrument and software I used.

But I get your point.
smokarz is offline  
post #80 of 116 Old 12-19-2012, 09:16 AM
AVS Special Member
 
curttard's Avatar
 
Join Date: Aug 2005
Posts: 1,320
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Liked: 27
Quote:
Originally Posted by superleo View Post

Again, and again and again.
You want a DIY screen to give you comparable data of a commercial screen...

To be fair, MM routinely gives gain figures for his screen. So he IS giving comparable data to a commercial screen...he just gives them without having actually measured them.
Quote:
At the end.. the information provided does not satisfy your requirements try something else...
You are missing the point, it is a DIY screen.

This is funny to me. You say it's absurd to provide any kind of data because the tools required -- hugely useful in many respects other than "proving" the superiority of one screen over another -- cost a bit of money. So your advice is, instead, to just keep trying screens until you find one you like, at $60, $70, $80 a pop and lots of time and effort. I can tell you that personally I spent about $200 getting my screen painted with RS-MM-LL, between sprayer, supplies, and paint; plus another $50 or so trying small amounts of two another paints, plus far more time than I would have liked; the i1 Pro, by comparison, is $250. I, for one, would enormously have appreciated some data being out there so I could narrow my decision down in advance. Why is your advice simply that everyone keep reinventing the wheel? I was under the impression that generally in human civilization it's considered a good thing for things to be recorded, so that we can learn from each other's mistakes.
Quote:
Originally Posted by prof55 View Post

Gain: I'll assume you mean both on and off-axis gain in your request. A single figure, (i.e. 1.5) while it might sound good, wouldn't really tell us a lot. Brighter is better, but if folks on the side see a sharp drop off, the application won't work for everyone. So a single gain figure, while fun for comparison, is basically a bare start.

Gain figures can help us narrow down our choices, and as has been pointed out, these numbers ARE provided -- they just aren't substantiated by measurements. Hotspotting can quite easily be indicated by photos or testimonials.
Quote:
Color: ...No, I'm not suggesting that we should disregard this spec entirely, I'm merely pointing out that it is not a sacred as some seem to think, and it is easily checked by the simple comparison suggested above. Further, if a DIY application were to show a pronounced "push" (as some have), it would be immediately spotted by those who try it.

Color is important enough that it's neutrality is routinely touted as a plus for a given screen, and presumably we all feel it's important enough that controls on our display to adjust it are vital. Further, if you have to decide between two otherwise similar screens, wouldn't you choose the one that's more neutral? Assuming you're one of the (apparently rare) enthusiasts here who actually calibrates his displays, having to make significant adjustments for a non-neutral screen will result in loss of brightness.
Quote:
Finally, I doubt the ability or need for the average DIY screen builder to interpret and apply the specs you find so dear.

You don't think the average DIYer needs or can understand gain figures or color neutrality? Then why is every post here about brightness and color etc? Since few seem willing to provide pictures that can accurately depict how two screens compare in brightness, and even fewer compare multiple screens side-by-side, you don't think simple, measured gain numbers would be useful?
Quote:
The final judgement is ultimately the satisfaction of the eyes and ears of the user, as it should be.

Sure. However, I'm absolutely stunned at the notion being put forth here that it's somehow not a useful or even necessarily desirable thing for us to share objective data, so that more of us can hoepfully arrive at a "satisfying" solution the first time, rather than having to repeat the same process of trial and error as hundreds before us. It's truly bizarre to me that you seem to welcome and find useful posts of firsthand impressions like "this screen has lots of pop and my wife said it's like looking at a window", while downplaying the utility of things like "this screen has a gain of 1.1 but pushes green out of the box; once calibrated back to 6500 it has a gain of .9".

The difference in many screen solutions is a matter of degrees. Having, at the moment, four different ones on hand, I can tell you that the difference between them is probably entirely unnoticeable if viewed in isolation one after the other; you have to see them side-by-side. In fact, after having a BOC screen for the past two years, and then switching to RS-MM-LL, not one of my regular guests asked "did you get a new screen?" or said "it looks brighter than it used to" -- they simply didn't notice at all.

So if, according to you, things like gain and color neutrality aren't needed, can't be understood, and aren't important to most people here, then why is there this continual quest in the first place? Why not just recommend OTS paint and be done with it? Obviously, those small degrees DO matter to most of us or we wouldn't be here.
curttard is online now  
post #81 of 116 Old 12-19-2012, 09:21 AM
AVS Special Member
 
bud16415's Avatar
 
Join Date: Jan 2006
Location: Erie Pa
Posts: 3,128
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 15
To the question of improving CR at the screen and the physics or science behind it.

Let me ask a question and let me simplify it as best I can. Say we have some surface and we are not concerned about color correctness or none of that just black and white and the shades of gray between. Let’s say the projector is good and when projecting black it sends out zero units of light and to do white it sends out 10 units of light. We know CR is the times brighter the best white is over the best black. So in this case its 10/0 = infinity CR. In the real world the brightest white may be 10 and because projectors can’t shut off all black maybe .001 is the best black. 10/.001= 10,000 so we would say this projector at best in on / off CR is 10,000:1

Now we have a screen that “Improves Contrast” to do that it has to act differently on light that’s on the weaker end and thru “Special Gain Properties” the screen only works on amplifying the brighter light or attenuates darker light. So in our example above the screen is really good and the 10 units of light hit it and it reflects all 10 units back into the room. But when the .001 units of light (black) hit the screen the screen somehow knows it’s a dimmer light and the properties of the surface change during that one frame of the movie in that one area on the screen and send back to the room only .0005 units of light. Now we measure the CR off the screen as 10/.0005=20,000 or we get to view an image of 20,000:1 CR. Now that’s a really dark black and we are also talking about improved shadow detail. So that might be a situation where we have some 10 unit white and some .1 units of dark gray light. The screen does its magic and sends 10 units into the room of white and still has this correction ability on darker light and takes the .1 units and tames it down to say .05 helping us darken up a dark gray a bit. We keep going along with this and at some point we are at 10 units white and say 5 units gray giving us that middle gray. By this point the screen really has to think about what to do, maybe shut off the ability of darkening darks because we are at the half way point and maybe now the screen should stop working on blacks and MM has told us the screen can’t make more light than the projector can or I would say maybe at the halfway mark we start amplifying things so when we get to 10 out of the projector we have 20 coming back into the room. But that would be ridiculous.

Every screen I have ever seen was passive and did the same thing to all light regardless of the lights intensity.

Maybe someone can explain where my math logic isn’t correct. This improving contrast screen is like a crossover network in speaker design. I just can’t figure out how a reflective paint that is passive, can understand the difference in bright light and dim light and ether pass all on one and attenuate the other.

Explanations Please?
rolleyes.gif


Bud

bud16415 is offline  
post #82 of 116 Old 12-19-2012, 10:26 AM
Advanced Member
 
Kirnak's Avatar
 
Join Date: Nov 2009
Posts: 822
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
@ Bud16415:
I think realistically we're talking semantics. Obviously, it's impossible for a passive screen to improve upon the PJs native contrast. That goes without saying. So what does it really mean when somebody calls a screen "High Contrast"? I think what is actually being touted is a screen that retains the illusion of the PJ's native contrast. In other words, take your example above. Take that PJ producing 10 units of light at brightest, and for simplicity's sake let's say 1 unit of light for black. That gives us a 10:1 contrast ratio. Now, lets say we have a screen that reflects all light perfectly. In a perfect room with no reflected or ambient light that screen will maintain our 10:1 contrast ratio. OK, Now lets add 5 units of ambient and reflected light to that room. Our perfect screen is now reflecting 15 units of light for white and 6 units of light for black. Our outstanding CR has dropped from 10:1 to 2.5:1. Here comes a "High Contrast: screen that only reflects 50% of the light that hits it. Now, white is 7.5 units of light and black is 3 units. Still 2:5:1. But what has changed? Black is now 3 units of light, which compared to other objects in the room is far darker than the other screen at 6 units of light. The eye and brain then decide that 3 units is blacker than it really is, and we see a blacker black than what is really there. the 7.5 units of light is still the brightest thing around, so we see a whiter white than what is really there.

If that makes no sense, and it probably doesn't, look at this picture. The squares labeled "A" and :"B" look like very widely spaced shades of gray and white. In fact, they are precisely the same shade of gray! If you don't believe me, use a color checker.


So, no, a passive screen can have no effect on measured contrast. But it can have an effect on perceived contrast. Now, I'm not supporting or denying anyone's claim to what their paint does. I'm just saying it is possible for a passive solution to appear to retain more of the PJ's native contrast. And since we see with our eyes and not meters, appearance matters.

I think what should be obvious here as well, is that the room matters a great deal. IMHO, more than the paint. Hence my decision to go with a completely treated room and white paint.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.




To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



[URL=http://
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Kirnak is offline  
post #83 of 116 Old 12-19-2012, 10:33 AM
Moderator
 
prof55's Avatar
 
Join Date: Oct 2002
Posts: 1,412
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by curttard View Post

So if, according to you, things like gain and color neutrality aren't needed, can't be understood, and aren't important to most people here, then why is there this continual quest in the first place? Why not just recommend OTS paint and be done with it? Obviously, those small degrees DO matter to most of us or we wouldn't be here.

The parts you left out of my quotes make it clear that gain and color accuracy ARE important in my opinion, and demonstrate easy ways to achieve them without instrumentation.
Quote:
Originally Posted by smokarz 
One made a claim that his screen has a gain of 1.3, and I like to know how he arrived at that conclusion.

Were this your original question, I suspect it would have been answered. In fact, here is but one of your statements that I have been responding to:
Quote:
Originally Posted by smokarz 
If none of you have any concrete data and evidence to present to the general public, then it is nothing more than he said/she said. All gibberish, IMO.

A bit stronger than your current position, and I applaud you for that. We'll have to agree to disagree, but I would still like to know what you feel is a good choice for specific test instruments.

Kirnak: EXCELLENT explanation! I agree, it is mostly semantics that is causing the disagreement about CR.
prof55 is offline  
post #84 of 116 Old 12-19-2012, 10:37 AM
AVS Special Member
 
curttard's Avatar
 
Join Date: Aug 2005
Posts: 1,320
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Liked: 27
Kirnak, your hypothetical high contrast screen that only reflects 50% of light sounds like a simple grey screen. I believe the claims Bud takes issue with are that a special screen paint can in some way beat the contrast performance of an OTS grey by doing something other than simply reflect less overall light. For example, pb_maxx's statement on the first page that "the very dark screen on the right can have the same or greater white levels as the white screen and also lower the black level bottom considerably", or MM's on the first page that his paint succeeds at ""Keeping" the Blacks at a lower level without attenuating the Whites."

Personally, I think strong statements like those, that seem to defy common sense, physics, and simple experience, should be backed up by measurements; or at the very least by screenshots that accurately depict what they claim. This also goes for other statements that confidently state the superiority of one solution over another in regards to various properties. I'm not sure why an idea so sensible is being met with such resistance.
curttard is online now  
post #85 of 116 Old 12-19-2012, 10:50 AM
AVS Special Member
 
curttard's Avatar
 
Join Date: Aug 2005
Posts: 1,320
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Liked: 27
Quote:
Originally Posted by prof55 View Post

The parts you left out of my quotes make it clear that gain and color accuracy ARE important in my opinion, and demonstrate easy ways to achieve them without instrumentation.

Maybe I'm missing it but I don't see where you suggested any way to compare brightness of two screens you haven't made yourself without someone posting gain measurements. As for your method of judging color neutrality, I won't argue with the method, but I don't see anyone doing that, including those who profess the color neutrality of their solutions.

As I've said many times in this thread, I think there are levels of usefulness in judging this stuff and I agree with you that there is more than one way to provide useful info.

Someone posting "my screen looks awesome and everyone who saw it said it's great!" is of little utility to me. Someone saying "this screen is definitely brighter than the blackout cloth I used to have" is slightly more useful. Someone saying "I put it up side by side with blackout cloth and it's brighter with slightly lighter blacks" is still more useful. Photos that accurately depict that are even moreso. And then there are measurements. Personally I'd be happy with good comparative screenshots of the type I've described in this thread, but those are few and far between.
curttard is online now  
post #86 of 116 Old 12-19-2012, 10:52 AM
Advanced Member
 
Kirnak's Avatar
 
Join Date: Nov 2009
Posts: 822
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
@ Curtard post #80: Very well written post and I agree with most of your points. However, I don't think it is fair that others be required to play by our rules. I think it's totally reasonable to agree to disagree. I think readers can note for themselves one paints lack of documentation compared to another's complete analysis.

Part of the problem I think is that screens can never be fully analyzed, at least by the hobbyist. Color is fairly easy, gain is more difficult. Hotspotting is very hard to measure, yet easy to see. Clarity, graininess, shimmer, sharpness, these things are virtually impossible to measure at our level, yet can be fairly easy to see. A complete analysis of any screen will always be part objective and part subjective.

As far as screen shots, their usefulness can be endlessly debated. A good photographer who is trying to capture what the screen looks like can show a decent representation of some aspects of a screen. Does the screen look washed out with ambient light for instance. Of course, a photographer can easily make the screen look better than what it really is, if he chooses to do so. But, that holds true for objective measurements as well. I can put any numbers I want into a graph... In the end we rely on the honesty of the poster. Some things--such as clarity, graininess, shimmer, sharpness--just can't be shown in a screen shot due to size limitations. Some of that is viewer dependent as well. My wife doesn't even see graininess that bothers the hell out of me. Plus, some things just don't show up in photos. The 5020 I'm returning has horrible flare. But, no matter what I do, I can not capture that flare with my camera. I haven't the slightest idea why.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.




To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



[URL=http://
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Kirnak is offline  
post #87 of 116 Old 12-19-2012, 10:54 AM
AVS Special Member
 
bud16415's Avatar
 
Join Date: Jan 2006
Location: Erie Pa
Posts: 3,128
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 15
Quote:
Originally Posted by Kirnak View Post

@ Bud16415:
I think realistically we're talking semantics. Obviously, it's impossible for a passive screen to improve upon the PJs native contrast. That goes without saying. So what does it really mean when somebody calls a screen "High Contrast"? I think what is actually being touted is a screen that retains the illusion of the PJ's native contrast. In other words, take your example above. Take that PJ producing 10 units of light at brightest, and for simplicity's sake let's say 1 unit of light for black. That gives us a 10:1 contrast ratio. Now, lets say we have a screen that reflects all light perfectly. In a perfect room with no reflected or ambient light that screen will maintain our 10:1 contrast ratio. OK, Now lets add 5 units of ambient and reflected light to that room. Our perfect screen is now reflecting 15 units of light for white and 6 units of light for black. Our outstanding CR has dropped from 10:1 to 2.5:1. Here comes a "High Contrast: screen that only reflects 50% of the light that hits it. Now, white is 7.5 units of light and black is 3 units. Still 2:5:1. But what has changed? Black is now 3 units of light, which compared to other objects in the room is far darker than the other screen at 6 units of light. The eye and brain then decide that 3 units is blacker than it really is, and we see a blacker black than what is really there. the 7.5 units of light is still the brightest thing around, so we see a whiter white than what is really there.
If that makes no sense, and it probably doesn't, look at this picture. The squares labeled "A" and :"B" look like very widely spaced shades of gray and white. In fact, they are precisely the same shade of gray! If you don't believe me, use a color checker.

So, no, a passive screen can have no effect on measured contrast. But it can have an effect on perceived contrast. Now, I'm not supporting or denying anyone's claim to what their paint does. I'm just saying it is possible for a passive solution to appear to retain more of the PJ's native contrast. And since we see with our eyes and not meters, appearance matters.
I think what should be obvious here as well, is that the room matters a great deal. IMHO, more than the paint. Hence my decision to go with a completely treated room and white paint.

Your answer makes perfect sense and I have to admit I knew the answer to the question I asked. I have posted a 100 times the same comparison you just made and then threw in the variable of say I need 15fl of light coming from my screen and I have say a desire for 5fl of comparable lights turned on in my sports bar so people can see to eat their pizza and drink their beer. If I hit the white screen with 15fl and dilute it with 5fl ambient or I make the screen a ND2 gray and hit it with 30fl and attenuate 2.5 of the 5fl of bad light the ND2 gray will preserve more of the native.

I also then tried to show how if you bump the lumens even more and partially compensate for the extra illumination with ND gray and return an even brighter image in relationship to the ambient in the room the viewer’s eyes will change aperture and increase perception of contrast. It is in this perception in ANSI like images where we see the inky blacks. It’s no different what the eyes will do and the argument above about taking a picture of a screen and the camera works like our eyes maybe even better at perceiving the greatest contrast possible. Sometime when you go to the eye doctor and get drops go home and view your screen. If its cinematic it won’t seem too bad if its plasma like it will burn your eyes out, but both don’t seem to be all that different when viewed normally.

I agree and have posted quite a few times about the trilogy of projecting being the projector, room and screen. All 3 being equal and all three being matched. In your darkened room with a good projector and white screen you most likely have hit the sweet spot. I have most likely 4 times your lumens with a much darker screen and a ton of ambient light directed away from the screen and darkened walls and ceiling to take care of it after its used once. And that’s my sweet spot. I have always added that such a setup also is very amazing with the lights off.


Bud

bud16415 is offline  
post #88 of 116 Old 12-19-2012, 10:57 AM
AVS Special Member
 
bud16415's Avatar
 
Join Date: Jan 2006
Location: Erie Pa
Posts: 3,128
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 15
Quote:
Originally Posted by curttard View Post

Kirnak, your hypothetical high contrast screen that only reflects 50% of light sounds like a simple grey screen. I believe the claims Bud takes issue with are that a special screen paint can in some way beat the contrast performance of an OTS grey by doing something other than simply reflect less overall light. For example, pb_maxx's statement on the first page that "the very dark screen on the right can have the same or greater white levels as the white screen and also lower the black level bottom considerably", or MM's on the first page that his paint succeeds at ""Keeping" the Blacks at a lower level without attenuating the Whites."
Personally, I think strong statements like those, that seem to defy common sense, physics, and simple experience, should be backed up by measurements; or at the very least by screenshots that accurately depict what they claim. This also goes for other statements that confidently state the superiority of one solution over another in regards to various properties. I'm not sure why an idea so sensible is being met with such resistance.

Correct


Bud

bud16415 is offline  
post #89 of 116 Old 12-19-2012, 11:09 AM
AVS Special Member
 
curttard's Avatar
 
Join Date: Aug 2005
Posts: 1,320
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Liked: 27
Quote:
Originally Posted by Kirnak View Post

@ Curtard post #80: Very well written post and I agree with most of your points. However, I don't think it is fair that others be required to play by our rules.

Required, no. Asked to, sure. The bottom line is there are LOTS of posts on this forum that are very strongly and repeatedly stating a given screen's superiority in one or many aspects over any other screen solution, including commercial screens (barring maybe the very expensive Supernova or whatever that one is). I think it is only to be expected -- and only fair -- that some questions be asked: "How do you know?" and "Can you prove it?" being among them. Especially given the increased cost and difficulty of the custom solutions over an OTS paint -- as has been made clear in this thread, we are all penny-pinchers after all :P

As for screenshots, I think they are capable of showing relative differences. If one screen is claimed to have comparable whites to another with significantly darker blacks, it's easy to show this, as I've said. A checkerboard image, under-exposed so that the white squares are grey-ish, will let us instantly and easily compare the whites of the screen versus a test panel on top of it. The same image, over-exposed so the black squares are grey, will let us instantly and easily compare the blacks. Two simple photos can quickly prove or disprove claims or relative brightness and/or contrast.

Hotspotting between two screens can be compared with the usual flash photo or 100% white field, with the caveat that it will be less noticeable in person and with real content.

The bottom line for me is "why should I use paint x over an OTS paint of the same shade?", and if the answer is "improvements in a b and c" I would like some sort of demonstration of those improvements, either in the form of useful screenshots or measurements.
curttard is online now  
post #90 of 116 Old 12-19-2012, 12:02 PM
AVS Special Member
 
bud16415's Avatar
 
Join Date: Jan 2006
Location: Erie Pa
Posts: 3,128
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 15
This debate has been going on for years and one reason people like myself leave for 2 or 3 years at a time. IMHO screen science is not that difficult to get your hands around it’s like a math problem with half dozen equations and half dozen variables. It’s a simple problem but you have to grasp simultaneous equation math and not work on one equation at a time chasing your tail.

That and you have to buy into some simple logic like things that look blue like a blue ball when struck by white light are blue because they absorb all the spectrum except blue and reflect that blue light to our eyes. Likewise paint pigment can be a mixture of any color microscopic bits some white some black and some mirrors and the combination of all that pigment doesn’t change but our eyes combine it all into white or ND gray in the case of a good screen. The surface finish of the screen and sheen can give it a range between flat black and a mirror. The more like a mirror it is the higher the gain, focusing the most light in the tightest cone. More light in the cone means less light off axis. Another claim often made that goes contrary to logic. I have read a 1000 times about a screen that produces on axis gain of yes an amount like “1.4 gain” and in the next sentence its shown with a photo that confirms a visual it still has a 1.0 gain or better at 45 degrees off axis. The inventors of these screens deny that their vision could have also adjusted when walking over to take an off axis look and then the cam adjusted giving a photo of just what they saw.

A simple gray bolstered with extra lumens is looked down at as being different than a higher gain using lesser lumens and even labeled as inefficient. When actually when you think about it the whole concept of big screens is very inefficient. We are blasting out all this light and about 99.9999% of it is doing nothing only a very tiny speck of it is coming back to our two eyes and landing on the optic nerve, the rest is getting soaked up by all the stuff in the room that can’t tell if the CR is good or not. On the other hand if you have a couple hundred people in a theater it starts paying. And there is a little talked about experience when viewing a bigger illusion at a greater distance and how our eyes see and for that reason I love my 120”.

I like those above have no problem with people taking a less than scientific approach and by all means if it works for them and they enjoy the image then go for it and I might even give it a shot myself. But even people wanting to play around by the seat of their pants I think are helped by understanding the fundamentals. And anyone telling something that is not possible should be asked to back up the claim and anyone say posting an exact figure for gain or viewing angle or saying it betters something that has went thru a testing process should have to show some proof.

One time I was at the hobby store and they had these 5 pound bags of plastic snow that was made from tiny bits of plastic in rough cube shapes. I bought a bag and painted a board white with a thick layer of paint and then sprinkled on a thick layer of snow and let it dry pouring off the excess. It was amazing 1.543 gain and 186 degree viewing angle and whites that would melt your eyes. Ok my mom told me one hundred million times not to exaggerate. Anyway wasn’t much for movies but might look cool in the front yard with color lights on it for the holiday.


Bud

bud16415 is offline  
Reply DIY Screen Section

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off