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-   -   What is happening here? Opinions? (http://www.avsforum.com/forum/110-diy-screen-section/1444907-what-happening-here-opinions.html)

MississippiMan 12-12-2012 10:25 AM




























Summary:

SF v3 1.0

142" Diagonal 2.35:1 Drywall surface

Panasonic AE7000 mounted at the "extreme short end" of it's Throw Distance for the screen's size and using maximum Zoom

Screen was Smoothed, "spray Primed" and the Sprayed using a Graco HV2900 w/1.5 mm tip

Screen exhibits NADA graininess and NO hot spotting,

MississippiMan 12-12-2012 10:34 AM

Hint:

The darker the image, the more the apparent the difference between the Contrast enhancing ability of the White Surface and the SF Screen surface becomes.

Note the Date of this posting 12-12-12

pb_maxxx 12-12-2012 11:14 AM

well my pics are not as nice... but it's been shown before...

now consider these two screens... the white sintra screen on the right and the dark screen on the right.

most people have no idea 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 considerly, thereby a perceivable increase in contrast.


curttard 12-12-2012 11:29 AM

Quote:
Originally Posted by pb_maxxx View Post

most people have no idea that the very dark screen on the right can have the same oa greater white levels as the white screen and
also lower the black level bottom considerly,

True, and I'm one of them wink.gif

Can you put white and your preferred grey side by side in a shot with an ANSI checkerboard and take two pics, one exposed so that the whites don't clip and one exposed so that the blacks don't clip? I.e. a pic where the whites appear greyish, and another otherwise-identical pic where the blacks appear greyish?

pb_maxxx 12-12-2012 11:40 AM

Bud,
Sorry about the confusion. This is a macro shot of the two screens side by side. The pencil is just laying across both screens.
In a way...it's much like your coal black demo...without the ultra fL's.

...sorry guys...didn't mean to hijack MM's thread.

curttard 12-12-2012 11:56 AM

Quote:
Originally Posted by pb_maxxx View Post

Bud,
Sorry about the confusion. This is a macro shot of the two screens side by side. The pencil is just laying across both screens.
In a way...it's much like your coal black demo...without the ultra fL's.
...sorry guys...didn't mean to hijack MM's thread.

I for one would be thrilled to see pics like those I described above in this or a new thread.

MississippiMan 12-12-2012 12:05 PM

Quote:
Originally Posted by bud16415 View Post

MM
Looks like the macro texture of the paint combining with the micro texture being sealed with a high degree of surface sheen is causing some directional gain but well below the hot spot threshold. The unknown sample in comparison clearly has reverse properties.

The Screen exhibits no sheen or visible texture under normal light or projected light....and/or at any distance beyond 2'. The close-up example was being flooded by a 250 watt Halogen Work Lamp, The Screen / White Sheet of Paper example was a Flash shot. As in any screen with 1.0+ gain, there is a very slight viewing cone. I included on-axis and off-axis shots so that could/would be shown.
Quote:
The off axis shot clearly points out the ability of the painted screen to manufacture light. That’s the only explanation because we know nothing can manufacture darkness as darkness is the absence of anything and it’s virtually impossible to make more of something that isn’t anything.
Just because you cannot explain adequately what you see does not mean you have to litter up this thread with nonsense and sarcasm. I'll ask you one to cease and desist...or not to post on this thread again.I know you can offer something constructive...you just have to determine if you want to.

And no...the contrast enhancing ability of the Paint (on primed Drywall...see Summary) is "Keeping" the Blacks at a lower level without attenuating the Whites. That ain't making...that's called "retaining". And please note that every shot is taken in a reasonable but apparent amount of ambient light.
Quote:
Without any type of scientific measurements being taken I would have to venture a guess based on the screen shots and the darkness of the shadow of the arm in the photo that the screen itself is producing at least 3 foot lamberts of darkness in addition to what the projector is producing.

Why don't you be so kind and courteous as to remove such nonsense? It would speak highly of you, you know.
Quote:
Very nice work on the theater also. What type of theater seating did you use? They look very plush. I’m assuming the screen isn’t AT is there any issues with the sound stage being the screen is so enormous.

SeatCraft Vienna (4seating.com) I'm pretty sure you know exactly what is hiding behind that Drywall screen, and why AT considerations are of no concern, as well as to why the sound stage has no problem being expansive enough. But that is a subject for elsewhere so please limit your observations and responses to the subject of the Screen alone. Please.

Thank you.
Quote:
PB
That’s amazing also. Are you saying you can project white off a dark surface like that. The image of the pencil looks the same projected to both samples but the one on the right clearly has increased contrast. Good job.

We never rest....we just sometimes doze off a bit. You however seem to be intent with creating something akin to a intentionally disruptive banter. So stop. Once again. Please.

Thank you.

MississippiMan 12-12-2012 12:11 PM

I'll repeat again...do not make obvious attempts to disrupt this thread. Be constructive or do not post.

curttard 12-12-2012 12:26 PM

A grey ramp could be good instead of or in addition to an ANSI checkerboard -- it would make it obvious where white and/or black are clipping in the camera, so we could simply compare the lightest and darkest steps that DON'T clip.

pb_maxxx 12-12-2012 05:02 PM

PM sent.

curttard 12-13-2012 11:12 PM

Well, since no one else is really answering, I might as well keep this thread alive. MM, I assume you're trying to show that the screen has darker blacks than the piece of paper but comparable whites? It's hard to tell this from the pics because the only whites we have to go by are letters that are just a few pixels wide and full of chromatic aberration. How about an ANSI checkerboard where we have nice big areas of black and white side by side?

I'd ask that of PB as well since to a layman it seems impossible to believe that that dark grey he posted could produce "the same or greater white levels" as the white.

MississippiMan 12-14-2012 01:15 AM

Thanks for responding, but don't knock yourself out. wink.gif

Truthfully, we both(PB & I) have developed virtually Black Mixes that have that ability, but along with that comes the same caveats we point to as being detrimental as far as other Mfg Black Screen apps. It used to be said, "You can't duplicate those results with paint". Not so...but you can't go there without consequences. Graininess & Substantial Loss of Viewing Cone. Deal Breakers for me.

So we don't advocate their use. You could also honestly say that if we did, those same caveats would be subjects of derision, despite the accomplishment. We won't settle for that. It must be "Mo Bedder" .

In many ways, those "Black Apps" are similar to if not exactly like Bud's Black screen. A pure Black works great..(...well, a little push toward Blue...).but only when a grossly disproportionate amount of Lumen are hitting a very small area. You can't pitch that as being desirable or practical. the difference between them....much like A SF v2.5 6.0 HG

The mix I;m currently working on /showing is a ultra light Gray SF. Despite what was said before, under ambient or room lighting, and a projected solid pastel image, there is no visible texture (graininess) or sheen...at all. A Macro shot under intense light shows a very smooth surface....but no procedure done by hand using thinned latex will ever achieve a glass smooth surface. Close...but no Cigar. This stuff ain't Auto Enamel or Lacquer

Another thing. The reaction of a High Contrast paint to any projected image structure (pixel-ation...noise...screen door) will always highlight those items presence. Do away with such (Lycos / Panny Smooth Screen Tech, etc). and most of the potential for such just "disappears". I'm using a Panny 7000 here.so that is probably a factor. Soon up, Darby Doublet will be added.

I do indeed intend to get a Good Calibration Disc w/various Patterns, then take a series of better shots. Those were obviously hand held jobs, and intended to simply show that even under those "less than ideal conditions" that there is indeed something to look and see..

pb_maxxx 12-14-2012 11:04 AM

that's not to say though... that SF v3 10.0 screens aren't viable screens for dedicated but mostly direct viewing for those who need ultra black levels for ambient viewing.

i don't have HT to do any testing in at the moment. and life and a fire have hindered my progress on many fronts.

but i do have one or two teaser pics once MM has done his thing.

smokarz 12-14-2012 01:35 PM

There is a free calibration disc right here on AVS.

wink.gif

superleo 12-14-2012 02:24 PM

Look at here!? Oh my I've bee missing all the fun!

My two cents as some one that has some experience with DIY screens... Although I've never painted any kind of screen after experiencing different types of DIY screens I can see the advantages of having/making a painted screen even though I've never done one. There are several public mixes available in this forum that graciously some members had contributed (thanks MMan). If one does not believe on the benefits or advantages of such a thing you can start your thread to discus it. AVS rules state that we should stay on subject . Also, I do believe that screen shots represent factually what a scree/monitor/tv can do, and these are not easy to do. Regardless of measurements if one has any experience with projection and screens screen shots tell the screen's story. After all this is a DIY section, you don't believe on a specific performance plain and simple don't do/use it... You are welcome to try something else.

Personally I like MMman screens with or with out scientific measurement.

curttard 12-14-2012 03:25 PM

Quote:
I do believe that screen shots represent factually what a scree/monitor/tv can do,

No offense but they don't at all. Pretty much any screen with any projector can produce a screenshot with pitch black blacks and blinding whites given the right camera settings etc. I first came to this forum in the days of the Infocus 4805, and you can go back in that thread now and see screenshots with contrast that rival a top of the line JVC. I can tell you from firsthand experience as an owner that the 4805 wasn't capable of anything approaching that.

curttard 12-14-2012 03:29 PM

For those who want to take screenshots that tell us a little more; here is a nice ANSI image, just plug an HDMI from your laptop to your projector and take a picture, or better yet two pictures (one under-exposed and one over-exposed).


Kirnak 12-14-2012 11:15 PM

Quote:
Originally Posted by pb_maxxx View Post

i don't have HT to do any testing in at the moment. and life and a fire have hindered my progress on many fronts.

Dude! Are you and your loved ones OK? eek.gif I'm praying that it is so.

I think the most important thing to remember is to have fun and watch what you like. I'm a big believer in the scientific method of analyzing screens, but some aren't. For instance, when I'm listening to music, I love total accuracy. I've spent a lot of money with equipment and a lot of time doing analysis to get the most accurate reproduction of music. As soon as I put in an action flick all that goes out the window. LFE goes up well above what the director intended. Why? I like the house to shake when a bomb goes off. I like to feel the vibration of a helicoptor's rotor blades. It's what I like and I don't care that it's not accurate.

At the end of the day these are just movie screens that can be painted over in a day. As long as everyone is having fun and learning, life is good.

I don't mean offense to anyone. I understand the OP's point and I understand the reaction. I really like everyone involved and think you're all good people--both sides.

I think it's great when someone goes to the effort to analyze and post results. There's a lot of effort involved in doing that. I understand when someone doesn't want to do that. Readers can make up their own mind whether they prefer fully analyzed paints or follow someone's subjective advice. If somebody doesn't want to do all the work involved in measured analysis, they really shouldn't have too. If somebody wants to go to all the effort of analyzing a paint and writing up the results, that's a great contribution to the community.

I'm not throwing stones here at anybody, I'm far from without sin on this subject! Somebody slammed me for not posting all of my data on the Glidden paint and boy did I let loose on that psycho, Oops I mean poster! smile.gif See? It's easy to get personally involved. It'd be more fun if we could all get together for a beer once or twice a year. Puts a face to a faceless internet post. But it'd have to be here in Portland, 'cause we have the best beer in the world, and THAT is scientific fact. I've put considerable effort into that analysis! smile.gif

If any of this sounds weird or seems offensive, it's 'cause I had knee surgery today and am on massive painkillers. tongue.gif

superleo 12-15-2012 08:21 AM

Quote:
Originally Posted by smokarz View Post

There is a free calibration disc right here on AVS.

wink.gif

It has the most needed patterns even with out instruments. You would need a blue color filter if your projector/tv doesn't have a blue mode.

http://www.avsforum.com/t/948496/avs-hd-709-blu-ray-mp4-calibration




NewGate88 12-16-2012 09:34 AM

Quote:
Originally Posted by curttard View Post

No offense but they don't at all. Pretty much any screen with any projector can produce a screenshot with pitch black blacks and blinding whites given the right camera settings etc. I first came to this forum in the days of the Infocus 4805, and you can go back in that thread now and see screenshots with contrast that rival a top of the line JVC. I can tell you from firsthand experience as an owner that the 4805 wasn't capable of anything approaching that.

Yes, they can. They don't always, but they can.

The validity of the screenshot is dependent on the intent, integrity, and skill of the individual taking the picture. Having posted some of my own, I know that one CAN (if pains are taken) accurately convey the appearance of the image with a photo.

Just as it is possible to post a screen shot that has very little resemblance to reality.

prof55 12-16-2012 09:44 AM

Q: What is happening here? Opinions?

A: Maurice is posting cryptic screenshots of something he thinks is obvious, but escapes me entirely. (You did ask for opinions!)

curttard 12-16-2012 11:31 AM

Quote:
Originally Posted by NewGate88 View Post

Yes, they can. They don't always, but they can.
The validity of the screenshot is dependent on the intent, integrity, and skill of the individual taking the picture. Having posted some of my own, I know that one CAN (if pains are taken) accurately convey the appearance of the image with a photo.
Just as it is possible to post a screen shot that has very little resemblance to reality.

Well, your original statement that I replied to said that screenshots "factually" show what the screen/projector can do, which isn't the same as saying it's possible for them to look like what you're seeing. But I'll still disagree with even that, though, for the simple reason that the photo cannot capture the full range of black to white in even a low contrast projector. Put up that ANSI checkerboard on your screen and take a photo, and you'll find that either the black squares or the white squares (or even both) are clipping in the photo.

NewGate88 12-17-2012 04:52 AM

Quote:
Originally Posted by curttard View Post

Well, your original statement that I replied to said that screenshots "factually" show what the screen/projector can do, which isn't the same as saying it's possible for them to look like what you're seeing. But I'll still disagree with even that, though, for the simple reason that the photo cannot capture the full range of black to white in even a low contrast projector. Put up that ANSI checkerboard on your screen and take a photo, and you'll find that either the black squares or the white squares (or even both) are clipping in the photo.

I didn't MAKE any original statement. I was just disagreeing with your blanket statement that screenshots are basically useless.

smokarz 12-17-2012 06:10 AM

Quote:
Originally Posted by NewGate88 View Post

I didn't MAKE any original statement. I was just disagreeing with your blanket statement that screenshots are basically useless.



The validity of screenshots have been dissected thoroughly on this forum and elsewhere.

MississippiMan 12-17-2012 08:07 AM

Quote:
Originally Posted by smokarz View Post

The validity of screenshots have been dissected thoroughly on this forum and elsewhere.

Except on the "Screenshot Wars" Threads where countless judgements are made.....

......and anywhere else where someone uses a "Camera" to show the supposedly poor results of someone else's own efforts. Then...they becomes strangely valid.

While the uninitiated may well not know how to compensate for the variations Digital Point-N-Shoot & SLRs can introduce, those who do can indeed come very close to ACCURATELY portraying what they see using the Camera's abilities. As said elsewhere, perfection in representation is not the goal, (...nor even possible...) but coming very close is...and has been achieved before.

"Dissected" is actually a very good word to describe the concerted effort some feel compelled to make so as to wholly discount any posted visual exclamation as being "essentially worthless".
Then it's always comical to see the same person post up his own images of his own PJ / Screen and crow about the "supposed" quality.

The variables in PJ lumen output, screen gain or the lack thereof, room lighting or the lack thereof, zoom or no zoom, contrast on-screen and spot metering difficulties..................................

Simply put, it's really not easy to take an accurate depiction of what the eyes see, (...the eyes being the final judgement of visual nirvana, not a Graph or Pattern) but when it does happen, just as in any well composed photo, the quality of the resulting image speaks for itself.

Gary,

I didn't mean to confuse you. Or anyone else. A recent change in what is a SF 2.52.0 mix with the intent of boosting gain a small amount and also reducing the potential graininess effect to ZERO led to the creation of a very light gray concoction that did indeed have improved Gain and yet still improved contrast "on-screen" by deepening blacks without affecting whites.

At least as I and others with me could plainly see. The photos DO show that, albeit not as pronounced as in person, because I made no overt attempt to try to optimize my effort. I intend to make that attempt. I'd like to be able to use the AVS BluRay Disc, but since it seems it's just a File to be downloaded and burned onto a BluRay Blank that is escaping me at the moment. I do have no doubt that the difference would be easily enough discernible.

superleo 12-17-2012 09:36 AM

Screen shots have been discredited... Here we go again, by whom and why?...

Once again this is too a matter of opinion. My opinion that are very valid if done correctly... once again!? Just my opinion.

curttard 12-17-2012 11:07 AM

Quote:
While the uninitiated may well not know how to compensate for the variations Digital Point-N-Shoot & SLRs can introduce, those who do can indeed come very close to ACCURATELY portraying what they see using the Camera's abilities. As said elsewhere, perfection in representation is not the goal, (...nor even possible...) but coming very close is...and has been achieved before.
Quote:
My opinion that are very valid if done correctly.

I think you can take a picture that says "on my individual laptop screen, this is a decent representation of what I'm seeing when I look at the projector screen." Beyond that I don't think there's much else the typical screenshot can illustrate.

How do the initiated take pictures that accurately portray, for example, a screen's/projector's contrast when the camera is literally incapable of capturing the range?

How does a screenshot illustrate color accuracy unless it was shot with a manual white balance calibrated to a white card, and then viewed by everyone on correctly color-calibrated monitors?

How does a screenshot taken in any kind of auto mode illustrate off-axis brightness? I.e., unless we have an on-axis AND off-axis pic taken with the exact same MANUAL settings, including identical exposures, how can we possibly learn anything from such a pic?

Just as an example, here's the first image I found with a google image search of this forum for Infocus 4805. This was a 480p projector with Darkchip1, 300-350 calibrated lumens, 2000:1 contrast:



Despite those specs, and despite its real-world performance that I'm very familiar with, having had the projector for years until it died, that screenshot shows contrast that is quite literally unbeatable by the most top of the line JVC today. The white in the glare on the tunnel maxes out the brightness of the photo at 255; the black of the area behind the aliens plummets down to 2. In other words you could take any screenshot of any projector on any screen and you would not see better contrast. So how much trust can we put in a screenshot like that?

IMO any projector and any screen can look as good as any other in a screenshot. Their only utility comes in directly COMPARING aspects of one to another, and even this is only the case if they're in the same shot (assuming camera settings that allow for comparison of the aspects in question) or, better yet, in two different shots taken by a camera on a tripod in the same location with identical fully manual settings.

MississippiMan 12-17-2012 11:56 AM

Actually, as far as screen shots go of that particular scene, it's pretty crappy looking.

I just have to say you sooooo wrong in your last statement. It's the sort of generalized comment that in effect misleads far too many in it's all sweeping intent.

When I post a screen shot, it's always composed so as to represent what someone using a similar or identical PJ / Screen set up should and will achieve. Of course variable will exist, but just the same, with a little input all of those things can be compensated for. And never it is stated that the shown results would apply in every instance, so going on about how no one has identical circumstances is redundant...and really not so very true because in the end, it's the purpose of this Forum to educate people on what IS best and correct as far as matching Screen apps to PJs to Room conditions. Would that we could be 100% successfull at that all the time. rolleyes.gif

After having taken well over 30,000+ screen shots, most to "correctly" show what is possible and what is being seen, I feel confident in my ability to provide accurate assessments. Others might not have or feel that assurance, while others will steadfastly deny the very possibility of such ever being the case. And those individuals can certainly offer many reasons for that to be so. But all / everyone of those reasons are predicated on someone being unable to know what to do and how to do so.

And that is most certainly not the case in 100% of all instances.

curttard 12-17-2012 12:11 PM

Quote:
Originally Posted by MississippiMan View Post

Actually, as far as screen shots go of that particular scene, it's pretty crappy looking.

Yes, but I'm using it only to illustrate the particular property of contrast in this instance. It is literally, factually impossible for any screenshot of any projector on any screen to show brighter whites OR darker blacks than that picture of the lowly 4805. Knowing that the 4805 itself has mediocre abilities, one would almost be forced to conclude from that screenshot that it is on some magical grey screen that lowers the black level to Pure India Ink while simultaneously boosting the whites until they burn your eyes.
Quote:
When I post a screen shot, it's always composed so as to represent what someone using a similar or identical PJ / Screen set up should and will achieve.

Yes, but as I've said, it is simply impossible for the camera to accurately represent that. From a screenshot, my setup would appear to produce letterbox bars that are indistinguishable from the dark navy fabric on my walls. This is far, far from the case. Yet if I adjust the exposure to compensate and make those bars appear as grey as they do in person, then I have absolutely eye-searing whites -- I could put a plasma tv in Vivid mode in the shot for "comparison" and its 46ftL whites would be identical to my 5ftL pj/screen combo. So one might think "well, I need brightness, so this looks like the perfect projector/screen combo".

Yet in reality, I have grey bars AND dim whites, relatively speaking. There is no way for a single screenshot to show this. It's simply impossible. You need two pictures, one over-exposed and one under-exposed. It makes no difference how much experience one has in taking screenshots. The physical limitations of the camera make it literally impossible. So how do I (or you) take a picture of my setup that represents "what someone using a similar or identical PJ / Screen set up should and will achieve"?
Quote:
others will steadfastly deny the very possibility of such ever being the case. And those individuals can certainly offer many reasons for that to be so. But all / everyone of those reasons are predicated on someone being unable to know what to do and how to do so.

No, they are predicated on the physical limitations of digital cameras.

smokarz 12-17-2012 12:52 PM

I would love to see a screenshot put side by side with the actual projected image, so the 'uninitiated' can examine it themselves.


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