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What about a higher gain screen like the Stewart Ultramatte 150 or even Videomatte 200 if your looking for a 100" diagonal or larger image with a small amount of ambient light? The brighter image sounds more appealing since the Sharp already does a decent job with contrast. With the lower lumen DLP do we have a problem with ceiling mounting the projector and having a bright spot at low viewing angles?
 

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To further confuse the issue:


Does the answer depend on your light control? I mean if you have complete light control then you may have enough Lumens with your DLP for the Greyhawk. Greyhawks were made for DLP's and the blacks needed.


Also does distance from the screen and size of the screen also dictate a particular screen type? I will have a DWIN Transvision with a ISCO II so my distance from screen will close to 20'. In my case would a Greyhawk work given that I have complete light control.


Grace and Peace.
 

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Quote:
Its fairly easy to calculate your set up if you know the ANSI lumen output of your projector. The formula is: Projector LUMENS divided by screen SQUARE FOOTAGE multiplied by screen GAIN equals peak white FOOT LAMBERTS.
This formula was provided by Don Stewart of Stewart Filmscreen in another thread on AVS Forum. There are a couple of issues that can determine screen selection. For example, a 100" GrayHawk might be acceptable with the 9000Z, but larger screens would be begin to show a significant reduction in light output. The ability to control ambient light will be another factor. Some people might not enjoy watching their projector in a darkened environment, so they may need the additional light output with a higher gain screen. If you calculate the screen brightness for the 9000Z with a 16:9 100" diagonal (sq. footage= 29.58) GrayHawk (.95 gain), it is roughly 25ft/l with 800 lumens, and 19ft/l with 600 lumens. Both figures should be plenty bright for someone who can have control over ambient light.
 

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At Cedia, I am pretty sure that they used a Greyhawk to demostrate it.
 

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JeffY,


Is this because the better contrast of the Grayhawk improves blacks and colors that might otherwise be washed out by the ambient light?


How much ambient light are people talking about here? I will be putting the projector into the living room (could not swing a dedicated room). I will be able to put blackout shades on all the windows, but it will never be fully dark during the daytime. Definitely no direct light onto the screen, but definitely some ambient light seeping in from a corridor.


Is there an easy way to measure ambient light?


------------------

Before you criticize someone, you should walk a mile in their shoes. That way, when you criticize them, you're a mile away and you have their shoes.
 

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DLP, DILA, LCD all benefit greatly from a Grayhawk.


These digital projectors cannot and do not project an absence of light due to their reflected light designs, so if you want good black level, get a GrayHawk, just as simple as that.


19 ft is plenty..


-- Cain

 

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Or if you can't afford the $1,000+ Grayhawk, buy a $200-400 matte white (gain 1.0) Da-Lite or Draper.
 

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When I get a little further on my construction, I will get a 130" 16x9 GreyHawk. Can't wait...


I will get it from the the guys here at AVScience.


Grace and Peace
 

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Another option, which you don't see much talk about, might be the VuTec BriteWhite material with a gain of 1.5. I got one of these from AVS awhile back for use with my Davis clone DLP and have been very pleased with the results. I got it to last for a few projectors, my next may just be the Sharp and I'm doubting I'll see any reason to upgrade. Just my $0.02.


Cheers,

--Geoff
 

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Quote:
Originally posted by ggolamco:
JeffY,


Is this because the better contrast of the Grayhawk improves blacks and colors that might otherwise be washed out by the ambient light?

If you have a look at the stewartfilm web site they push the ambient light benefit of the GrayHawk quite a lot. My room is fully light controlled so the GrayHawk is less of a benefit. The way I see it is with a positive gain screen you would use the 600 lumens setting which should equate to a quieter projector and longer lamp life. I checked with Gordon (our UK ISF guru) and he also recons on the StudioTek for this projector.


Jeff
 

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I think that the projector isn't bright enough for a GrayHawk, I'm going for a 2.35:1 StudioTek (1.3 gain)


Jeff
 

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In my case, I have no PJ yet but I do have a screen: A Grayhawk 16:9 100". Bought material only for $485.


So the only thing I need to do is to figure out what projector to get... http://www.avsforum.com/ubb/rolleyes.gif


The original plan when I got the screen back in May was to use it with a VPL-VW11HT with Cinema Mode off, i.e. 1000 lumens, as soon as it was going to be made available this fall.


However, since then my focus has shifted towards the new 1280x720 DLPs, e.g. the Sharp, but I'm afraid that they would look too dim for my taste on the Grayhawk with their mere 600-800 lumens. (What's the matter with these new PJs http://www.avsforum.com/ubb/mad.gif )


For me, decent blacks are crucial to overall PQ and was the primary reason I got the Grayhawk in the first place. However, I also appreciate the more vibrant colors and how the picture pops out at you with a higher gain screen, especially with some ambient light present. Not surprisingly, I would like to have both qualities in my future setup.


Is there a magical threshold in ftL at where the desired pop factor would be achieved? If there is, given constant screen area and gain, one could easily solve for ANSI lumen in the equation given above in order to find out how bright the projector needs to be.


Let's say that some ambient light would be present. Even though critical viewing would be done in a totally light controled environment, it would be nice to be able to have some soft (ambient) light present in the room when having a couple friends over for a football game (got to be able to find those beers http://www.avsforum.com/ubb/smile.gif ), while still achieving that pop effect.


Also, what is the typical light output histogram of a UHP lamp? If such a lamp outputs 1000 lumens when new, how many would it output after 75% into its life cycle (e.g. at 1500h of totally 2000h)? And is the deterioration linear? These factors would need to be considered when choosing a PJ since one wouldn't want to fall below that ftL-threshold after only 100h on the lamp.


[This message has been edited by NiToNi (edited 10-04-2001).]
 

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I wouldn't worry to much about ambient light for football, in that I find with my 10HT with cinema black on that the image itself produces a good amount of room light anyway http://www.avsforum.com/ubb/smile.gif But I know what you mean, I'm have a bought a dimmer that I'm going to try with the overhead lights so that you don't have such dramatic shifts in room light. I.E. during the game/movie the room maybe really bright but then when you switch briefly to a commercial the room gets really dark. When the commercial starts it gets bright then dark and so on and so forth. If it interferes with the projector then I'll just put the original switch back on.
 

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Quote:
Originally posted by 704set:
Is there a consensus oth there which screen would be the best fit for the Sharp 9000?
Definitely no consensus. Most people praise the Grayhawk for its help with contrast. But the Sharp already has good contrast, so maybe a much cheaper matte white screen would do. But the Sharp is not very bright compared to some other LCD/DLP projectors, so to help the colors pop off the screen, maybe a 1.3 gain screen is the way to go. Ugh!


The good news is, it sounds like the Sharp looks good on just about any screen.
 

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No consensus, but think about this.


Contrast is one thing, black is another. No digital projector can project the absence of light very well, due to the nature of their function (reflecting light off of mirrors).


If you want black, then the GrayHawk is the one for you. If not, then it makes no difference.


-- Cain

 

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I used the 9000 on both a GH and a Draper 1.3 gain screen. Both were 100" diagonal 16:9. The image was, to me, far better on the GrayHawk. Blacks were deeper, colors were better, and the image felt more three-dimensional.


Light level was fine with the GH. The 9000 is like a supernova compared to the light output of my Sony 1292! But for the best image, I'd go 100" maximum diagonal for the GrayHawk/9000 combination.
 

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Pat, for those of us who can't afford a Grayhawk, do you think matte white is a reasonable compromise?
 
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