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Discussion Starter · #1 ·
This is the question for the video bigwigs - Mike Parker, Tim Martin, Ken Hotte, Curt Palmer, Stacey Spears, Guy Kuo, David Abrams, Michael Hamilton, Mark Haflich, Alan Gouger ETC ETC


Assume you have a dark, light controlled room. A Stewart Studiotech 16:9 80" wide 1.3 gain screen. And a front CRT projector say with contrast range from 0 to 100, with factory preset at 50.


Have you ever run across an installation, ISFed with grey scale set in vicinity of 6500, where the contrast is set say at 10, or even at 20 - or say even less, at 0? And this is assuming that any video processor/scaler with its own contrast control is set at the halfway mark where it doesn't change the contrast at all.


OR AM I CRAZY???


Two years ago, John Gannon ISFed and setup my then brand new Dwin HD-700 7" CRT setting contrast to 10 on a 100 scale, 50 being the factory preset. Back then I was using Bybeeized (with internal Bybee devices at AC input and outputs) PS Audio Power Plants to power projector and scaler and other front end components. And this was using USPL color filtered red and green lens, too, which decrease light output by at least 20 percent!


Since then, I've changed all my power cords to Granite Audio 10 guage cords with toroids each end for high frequency noise filtering. And I've changed from Canare and Better Cables Ultra video cabling to Wireworld (silver) video cabling. And almost 4000 hours now on projector. Wouldn't you expect that the additional hours would now require a boost in the prior contrast setting? But Michael Hamilton just the other weekend completed re-ISFing my system and setting contrast across the board to

--- "0".


SO AM I CRAZY or are these tweaks doing something????


***I challenge you guys to "FORGET ABOUT IT", that is, the usual jokes.

How about having a substantive discussion. And other folks with the Dwin HD-700, if you've ISFed your setup, what are you running your contrast at???
 

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It is possible to do the setup at a different master contrast setting than middle, but achieve the same image provided the gain controls for each CRT have enough range. You can think of the individual CRT gains as being in series with the master contrast. If you turn up one and the other down you end up with the same signal level arriving at the CRT. This of course assumes that you keep the signal within the linear range of each video signal amp stage.


Personally, I wouldn't prefer doing the calibration with the master contrast set to one extreme because that doesn't allow the owner to adjust the contrast up and down slightly to compensate for source differences.


Without knowing what was done to the CRT gains and the beam current or light output level, there is no way to evaluate what the low contrast setting means regarding to what the tweaks which have been applied. There are three variables that have changed and we only know one (the contrast setting). Basically we have at least one hidden thing (the individual gains) that alters the scale of proxy "meter" of contrast setting level so there is no way to use the contrast setting number to measure anything.
 

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Steve,


Guy is right. There are many variables here and without actually knowing all of them it is hard to determine what is really going on. I know I have setup several projectors with contrast real low like yours because the tubes just cannot do any more than that. John could have set the contrast at 10 and arrived at the same results that Michael did but using the gain controls.


Perhaps if we could get some more information on the settings i.e. where they were when John finished and where they were when Michael finished we could take a better look, but I feel that there would still be certain variables to make any kind of definitive answer.


Best of Luck,
 

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Discussion Starter · #4 ·
Thanks guys.


Following are the Gannon two year old vs the Hamilton current ISF settings:


A. Dwin "Hidden Menu" R G and B values:


Gannon ---- Hamilton


R 200 --------- 191


G 205 --------- 206


B 235 --------- 248



B. Dwin Transcanner 2 settings, E.G., 1080i and 480p Component Video

Dwin TS2 Input:


Gannon ------- Hamilton


Contrast 55 --------- 50


Brightness 53 ---------- 50


(Note: My impression is the Dwin TS2 contrast setting has very minimal fine tuning effect on contrast, whereas the projector contrast setting has much more significant effect.)


C. Dwin HD-700 Menu Settings, E.G., 1080i and 480p Component Video

Dwin TS2 Input:


Gannon------------ Hamilton


Contrast 10 --------------- 0


Brightness 35 ----------- -- 47


R Gain 40 ------------------ 40


G Gain 100 ---------------- 100


B Gain 0 -------------------- 0


R Level 43 ------------------ 35


G Level 10 ------------------ 7


B Level 67 ------------------ 62
 

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Discussion Starter · #5 ·
Guy, don't you or didn't you have the Dwin HD-700 CRT with color filtered USPL red and green lens??? And how wide and the gain of your screen?

How did your settings compare to mine listed above???
 

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Yes, there are other things that could play into a low contrast setting. I faintly remember where the contrast is usually set on the Dwin 700, but I would think it should be more towards the center than on the low end. But not knowing the source, if the processor is putting out more than 0.7 Vpp, that could explain the low contrast. And as David indicated, it could be related to the condition of the tubes. It's really hard to tell without actually being there.


I really don't think the addition or removal of certain gadgets, I mean tweaks:) could have any effect this.


I would say that if it looks right, don't worry about it. We all do things a little different to accomplish the same thing. And it's alright if it's done different. The most important thing is that you're not experiencing clipping or a darker than usual image.


"OR AM I CRAZY???"


No, maybe a little too critical. A few weeks ago you were boasting about your setup, now you've become concerned about perfection. trust me, this is all normal, we all wonder if it could be better...


And whatever you do, don't waste, I mean spend anymore money on gadgets, er tweaks to correct what may not be an issue.
 

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Discussion Starter · #7 ·
Quote:
Originally posted by mp20748
Yes, there are other things that could play into a low contrast setting. I faintly remember where the contrast is usually set on the Dwin 700, but I would think it should be more towards the center than on the low end. But not knowing the source, if the processor is putting out more than 0.7 Vpp, that could explain the low contrast. .
Mike, I have the Dwin Transcanner 2 processor/switcher. www.dwin.com lists that the processor is at 0.7 Vpp for component

inputs and for RGB outputs to projector.


And Mike, haven't you set up the Dwin TS2 several times along with setting up the Dwin HD-700 a number of times???
 

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Discussion Starter · #8 ·
Quote:
Originally posted by mp20748
I would say that if it looks right, don't worry about it. We all do things a little different to accomplish the same thing. And it's alright if it's done different. The most important thing is that you're not experiencing clipping or a darker than usual image.


"OR AM I CRAZY???"


No, maybe a little too critical. A few weeks ago you were boasting about your setup, now you've become concerned about perfection. trust me, this is all normal, we all wonder if it could be better...
Mike, I'm not being critical. I am perfectly happy with my setup and am keeping it as is. I'm perfectly happy with my tweaks and I'm keeping them as is. I am simply starting an interesting esoteric discussion, asking not only AM I CRAZY (come on Tim Martin, you know you want to say that I am!:D :D :D ), but more importantly, does the current ISFing of my projector and settings two years later support objectively to any extent that my further tweaks have been effective so that the projector runs more efficiently allowing us to set the contrast rate even lower than before.
 

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Discussion Starter · #9 ·
Quote:
Originally posted by Guy Kuo
Personally, I wouldn't prefer doing the calibration with the master contrast set to one extreme because that doesn't allow the owner to adjust the contrast up and down slightly to compensate for source differences.
Since my Dwin Transcanner 2 contrast remains at the factory preset midpoint of 50, this gives me any fine tuning that I need. So far, I haven't found the need to fine tune contrast at all, and the only source material so far that I've had to change the brightness from the settings Michael Hamilton set are for the local digital UPN station, for which I've setup a separate projector memory with reduced brightness.
 

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Quote:
Originally posted by Steve Bruzonsky
Mike, I have the Dwin Transcanner 2 processor/switcher. www.dwin.com lists that the processor is at 0.7 Vpp for component

inputs and for RGB outputs to projector.


And Mike, haven't you set up the Dwin TS2 several times along with setting up the Dwin HD-700 a number of times???
Only twice, the other Dwin setups were using other processors.


Based on your posted numbers, both calibrators were close enough for this to be a non issue...
 

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There are a lot of variables going on here. I agree with Guy. I would move the processor setting up a little to avoid reaching a projector range extreme. However, it is calibrated now and it works, so . . . if it isn't broke do not fix it.


If a tweak makes it better to your eye, its a good video tweak. Now there is a fundamental difference between a video tweak and a video nerd. However, perfect convergence is obtainable, ala Joe Kane.


Its 2:30 AM and I just finished making two batches of ice cream custard to freeze tomorrow morning.


Saw the new James Bond flick tonight at my local theater. Not very bright, very non uniform light levels on the screen (bright in the center) and no blacks, just gray. Ugh.
 

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I think the core issue here is Steve is baiting us to comment on the dramatic improvement that the "tweaks" in his system have rendered, rather than anything that John or myself have done.

Analogously, it might be that Steve is intimating (perhaps to my highly esteemed friend, Tim Martin) that some of the things that one would not suspect could make a difference, perhaps do, a la Chris Stephens and Reference Imaging.

I can't fathom how many of Steve's add ons do their magic, but the results are ever-present and luxuriously so.

When I worked for the Dark Side (read: Retail...HAH!) We connected a Cardas power cord to a #23 Levinson power amp. The only change...period. Whoa!!! A manifest difference in sound quality. I called Dave Nauber, who at the time was our territory rep, and asked what in the world was going on; how could this be? He was due in town within a few days, and though he heard a difference, he could not explain that with all the power supply filtering that went into a Levinson reference unit, how this could be occurring.

I think Steve's post here (and correct me if I am off base, Sir Steven!) is to get us thinking not so much about constantly improving the core hardware when we want to improve our systems (or get bored!...not sure which!) but to examine extraneous issues that can make a great deal of difference in the system outcome.

Whether it is an issue of overcoming a performance obstacle with an actual, bona fide tweak, or further adding to a systems synergistic properties, Steve has become the master at the concept of "more is less",

that is, more tweaks lead to less grunge, background noise, and one dimensionality both visually and aurally. We were viewing a scene with a hurricane, and not only did I hear an ant "toot", but could tell that it was a Red ant. When he appeared on screen, we both could see that he was ATSC red, and not NTSC! And you guys think that we make this stuff up!!!

Seriously, Steve's set up is the best 7" rig I have seen, principally due to John Gannon's initial dialing in of all mechanical related issues, and just a minor enhancing on my part to rein in the system characteristics that became altered as the image became brighter from the improvements in all the support items (cables / power enhancements).


One other thing: Steve's room is nothing short of ideal. The walls are completely video dark, so any light off the screen is conducive to image quality and does not get refracted with light colored walls or fabric. My opinion is this impacts video dynamic range to a great degree, and the fact that Dwin PJ can be run with contrast at "0" is indicative of the "perfect room".

Traveling around for another PJ company, I see rooms that win awards for their aesthetics (not that Steve's wouldn't, but I think Martha Stewart might clutch her chest when she first walked in...[ha!]) but any environment short of one that is darkish and light absorbing definitely impacts front projection to a degree substantially higher than can be imagined by the average consumer. No designer relishes working with "gray", let alone black, but when results matter, it can effectively be proved, especially in Steve;s room.


Now if I can just get him to tune into HD Net and watch his local hockey team, perhaps their fortunes will start to turn!!!
 

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Discussion Starter · #13 ·
Quote:
Originally posted by Coyotes
I think the core issue here is Steve is baiting us to comment on the dramatic improvement that the "tweaks" in his system have rendered, rather than anything that John or myself have done.

Analogously, it might be that Steve is intimating (perhaps to my highly esteemed friend, Tim Martin) that some of the things that one would not suspect could make a difference, perhaps do, a la Chris Stephens and Reference Imaging. ............................................................ ................

Seriously, Steve's set up is the best 7" rig I have seen, principally due to John Gannon's initial dialing in of all mechanical related issues, and just a minor enhancing on my part to rein in the system characteristics that became altered as the image became brighter from the improvements in all the support items (cables / power enhancements).
I think Mike's got me figured out. I know that subjectively, my tweaks improved my picture. But even with that improvement, my system needed re-ISFing to redo grey scale in consideration of the tweaks. At least that is my take. But again, this is my own subjective interpretation, I don't pretend to understand that much technically from an engineering standpoint. And I started this thread to have a good discussion, both subjective and objective, by inviting in some of the forum's (and indeed Earth's) best experts on video setup to discuss this. And hey, you can indeed disagree that the tweaks do anything re contrast level, that's ok, just please DO NOT tell bad jokes to make fun of me for my subjective interpretion.


Here's some threads discussing some of my tweaks:


Granite Audio power cords

http://www.avsforum.com/avs-vb/showt...threadid=38366

http://www.avsforum.com/avs-vb/showt...hreadid=148950



Wireworld (silver) video cabling (by the way, we measured the 5M RGB H/V Sync cables, bncs each end, on a TDR and measured perfect 75 ohm all the way across including bncs)

http://www.avsforum.com/avs-vb/showt...hreadid=136384



PS Audio Power Plants

www.hometheaterhifi.com/ go to Master Index under Power Conditioners for several PS Audio Power Plant reviews



PS Audio Power Ports

http://www.avsforum.com/avs-vb/showt...hreadid=163064


USPL ECP color filtered lens for Dwin Projector

http://www.avsforum.com/avs-vb/showt...threadid=37754
 

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Quote:
Originally posted by Coyotes
I think the core issue here is Steve is baiting us to comment on the dramatic improvement that the "tweaks" in his system have rendered, rather than anything that John or myself have done.

.......


I think Steve's post here (and correct me if I am off base, Sir Steven!) is to get us thinking not so much about constantly improving the core hardware when we want to improve our systems (or get bored!...not sure which!) but to examine extraneous issues that can make a great deal of difference in the system outcome.
Yeah, we know what's up ;).... The DWIN 700 is a very fine projector, they have done a very good job on the video performance of it. It's definitely one of the best 7" CRT projectors manufactured, however.... well..... ok, I'll be quiet.


I'll see for myself when I get out there.


Steve, I'll be sending my HTPC ahead of me.
 

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Discussion Starter · #15 ·
Mike, ya wanna send the MOVI with your card instead - won't it have as good or better performance and be a lot less finicky for me to setup??

When are ya comin'?????? Remember, my daughter has her surgery this Friday at minimum a week thereafter, possibly longer, I will be unavailable.
 

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Discussion Starter · #16 ·
Quote:
Originally posted by Steve Bruzonsky
(Note: My impression is the Dwin TS2 contrast setting has very minimal fine tuning effect on contrast, whereas the projector contrast setting has much more significant effect.)
Funny thing. I swear when I tried this last a few months ago, the Dwin TS2 contrast control seemed to have very minimal effect. But today, post-ISFing, I tried it and it is a very dynamic adjustment. Maybe I am crazy after all!!!??? (Still waiting for Tim Martin to come after me. Maybe he's on vacation!!??)
 

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Ok. I will ramble a bit.


I jumped in to discuss the 0 setting. Bottom line, set the contrast control down on the transcanner and move it up on the 700, no thread.


Do power supply tweaks make video differences. Yes! What a surprise. Make the power cleaner, make greater reserves available, filter the suppply better, use bettter caps, make the circuits better, use faster chips, wider bandwidth etc. Ask MP about drastically increasing the size of 2 caps on the Marquee neck boards (caps that were added to the bds to protect the tubes during turnoff and that should do nothing to improve the spot)

(I guess Chris and Ken and the other modders may know something the engineers don't)(naw can't be) and improving a chip on each board and 4 more chips elsewhere. Change a few resisters to eliminate convergence drift. Please, I will not argue here. The results speak for themselves.


Now why do certain tweaks work. Basic EE theory cannot explain some of them. So an engineer may laugh. I am an engineer (at least I was one many years ago). I do not laugh except at those idiots, yes idiots, who do laugh.


Now I own a high end audio/video store. I have sold maybe $60K of PS Audio stuff to tweaks this year. Lots of non PS wires and cords too. So I am biased, right?


Sorry, guys, expensive line cords can make substantial audio and video improvements. (They can screw things up too. So be careful. Use your eyes and your ears.)


Can I explain why somethings work? Sometimes yes, often no. Laugh at people who spend money on something YOU KNOW IS STUPID. Its stupid because you KNOW its stupid, STUPID. Improvements, even those others maybe more stupid than you, see and hear. It just can't be. Can it? Be happy with yours, theirs can't be better. It just can't be because you know it.


The earth is flat, and man will never fly. Hell even Steve B can fly (with the aid of a plane)


Steve. Congrats on your daughter's Bat M. We all wish her a successful operation and wish her a speedy and gentle recovery.
 

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Steve,

it'll be later this month. I may have a MOVI by then. Oh, you'll never convince Tim that any tweak would improve on a 7" electrostatically focused projector - he's far too practical.


The best setup for contrast on your TS2 would involve a scope and AVIA's step pattern. You'd need to adjust the contrast and brightness for 100IRE and 0 or 7.5 IRE black level. Forget the factrory presets, they could only apply if you used the same input source the factory used. The rated 0.7 Vpp output of the TS2 is contingent on the contrast being properly adjusted using a scope/input source, and at that point (100IRE) you should see 0.7 Vpp on the output BNC's. Increasing the contrast would also increase the output from the TS2.



many an engineer would agree that changing components would make a slight difference in performance, they know and understand the BOM, and why cost is a factor in manufacturing and profit. The problem has been that there has been very little actual proof as to a real increase in making these changes, for instance, who has improved the performance of a projector and has provided actual data on an increase in the bandwidth?


Who has performed such mods and tweaks and has provided evidence of technical data showing a lower S/N?


It all seems to be subjective. And of course, there's always the claim when replacing leaky caps. If there's truly an improvement, why can't it be documented. Many of us make changes to various products (my self included), but the real change has more to do with components being old and leaky.


There was a time awhile back at INFOCOMM when projectors where displayed in a "shoot out" and from that same signal shoot-out we knew how well the projectors compared. Now it's all about hype.


Personally, I think that people who believe that cables should have a polarity, and that you should raise your cables off the floor to improve the sound, have entered the "Twilight Zone"
 

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Discussion Starter · #19 ·
Well, Mike, as my home theater was the FIRST featured in a magazine using cable elevators, you will be officially WELCOME TO THE TWILIGHT ZONE. Now if this thread degenerates into a slam the cable elevator

thread as a result of your joke (like the thread at the $20K up forum), then you will find yourself in the twilight zone permanently.


As for your instructions re the best setup for contrast for my Dwin setup, my understanding is that is precisely what Michael Hamilton, and John Gannon two years before him, did!


Please lets keep this thread substantive. Please avoid those jokes which are funny to you and belittling to someone who tweaks. Thank you.
 

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Quote:
Originally posted by Steve Bruzonsky


Please lets keep this thread substantive.
OK, Steve, what is your intent with the thread?


You invite us to comment on a non issue, and then you reveal your real intent, and that is that you want us to know how tweaks can have an impact on our projectors. So what is it want us to do?


I'm not making fun of you and your hobby. I would believe anything that's proven, that's why I said "I'll see for myself when I get out there"

I'm into modding and tweaking stuff, but I'm not into believing without proof. When I designed my mod, I sent it out to be tested and evaluated, it has as well been tested at two independent testing labs, and also by two very competant engineers. I did this because there were things that I needed to know, I needed to "substantiate" my findings.


Now, I'll stand back off of this tread, and keep an open eye to see the "substantive" proof as to whatever you're trying to do here.


Sorry if you're offended, but I'm only stating my position on this matter.
 
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