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Discussion Starter · #1 ·
I have got a JVC HX1 on the way to me and the dealer I got it from has offered me a really good deal on a 106" 16:9 Draper Clarion screen with m1300 coating. The projector will be in a room with total light control and will be projecting about 17' with the front row being at about 9' from the screen.


Does this projector/screen combo sound like a good match? This is my first front projection set-up so I'm still learning, but the 1.0 gain of the Draper m1300 has me worried if my setup will be bright enough from that distance on that size screen.


Like I said earlier, the dealer is offering a good deal on the Draper, but if I will be disappointed in it, I would rather go another direction.


Any help is appreciated.


Mick
 

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If we take 800 lumens as a real number, the screen brightness would be 24 ftL for first hours and about 12 ftL close to the end of bulb's life. But we live in real word, so taking into account that:

a) lion portion of watching time will be with about 60-70% of initial brightness (bulb may loose about 30% of brightness within first 200 hours);

b) the real light output less then given in the spec;

c) after professional calibration the light output becomes lower in about 1.5 times;


I would suggest to consider a screen having at least 1.4 gain. Another constrain comes from the the viewing angle for the first row, which is about 46 degrees. This rules out any screen with narrow and even average viewing cone.


The resulted list of choice is small enough:

- Carada Brilliant White;

- Stewart Ultramatte 1.5;

- SilverStar (questionable - personal preferences/tastes, the viewing cone is on the edge of acceptable).

Added: I recommend to check prices with Jason Turk (AVS, 585-454-1460 x10, [email protected] ). He has very good deals and he is honorable seller.
 

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Well, I have an HX1 and I have a temp screen that is only 1.0 gain. (80x60) It is plenty bright enough right now but I only have 50 or so hours on it so far. I ordered a 1.4 gain screen for it though. My final screen size will be 110 inch diag 16 x 9 . Its in a totally light controlled room with black ceilings and upper walls. GOM etc...



My pj is calibrated by William Phelps and had a final lumen output of 530 lumens.


I don't think you will go wrong but depending on cost, consider the Carada brilliant white screen for under700 bucks. Its 1.4 gain and the sample I have looked awsome and about the same as the Ultramatt 150 of stewarts as far as picture quality.


FWIW
 

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Quote:
Originally posted by PCARACER
I don't think you will go wrong but depending on cost, consider the Carada brilliant white screen for under 700 bucks. Its 1.4 gain and the sample I have looked awsome and about the same as the Ultramatt 150 of stewarts as far as picture quality.

FWIW
From my observations Carada BW is better than Ultramatte for large viewing angles for two reasons:

- it has less brightness drop for angles 40-50 degrees;

- picture loses less contrast for large view angles.


That's why I put Carada BW the first in the list.
 

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ehScorpio,


That is good to know. I feel even better about my purchase. Can't wait to get the screen up.


I better get my butt up there and get started on the trim work so I can finish this thing.
 

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I ran my sx21 on a 144 inch m2500 for a while and it look great. The only problem i had was that this material needed to be stretched every couple of months.
 

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Discussion Starter · #7 ·
Thanks for the replies. Sounds like I need to look at a screen with a higher gain.


One other question. Will I lose black levels by going with a higher gain screen? I'm still learning. Is there a screen FAQ??


Thanks,


Mick
 

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Black levels wont change compared to white levels. Its all relative to your on/off contrast. Its the final footlamberts that determines how everything will look. In other words, the blacks at 15 foot lamberts on a 6 foot wide screen with the HX1 will look exactly the same as 15 footlamberts on a 20 foot wide high gain screen. 40 footlamberts on a 10 foot wide screen will look higher and more grey. ( These numbers are not actual calculations but just there as an example to make a point!!!)

You could fine tune the final brightness with a ND filter depending on your taste. You can always go dimmer with the high gain screen but with a dim screen you can't go brighter. Now keep in mind there will be a viewing cone to deal with but most theaters with seats in front will not notice it depending on the screen. I am using a 110 inch diag screen with 1.4 gain. My final footlamberts calks out to 19. It looks plenty bright to me and I have to squint on some bright scenes. Now over time when the bulb starts to go down 30% or so, I should be safe as that will only put me at 14 Foot lamberts or so.


Make sense?


Good luck.
 

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Quote:
Originally posted by Jon_Patrick
I ran my sx21 on a 144 inch m2500 for a while and it look great. The only problem i had was that this material needed to be stretched every couple of months.
Not the case for Mick's setup. M2500 has narrow view cone. And if first row is within 9' of 106" screen, viewing angle is about 46 degrees. Hotspotting will be terrible...
 

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I have a 120 inch diagonal M2500 and I can walk right up to the screen and no hot spotting. I'm projecting at 19 feet from the screen though.


The M2500 has a very smooth transition of gain as you move off access so yes you will see a slight drop off in brightness from one side of the screen to the other when sitting way off access like 40 degree to one side.


As long as you use a long throw distance, hot spotting isn't a problem with the M2500. I have people over that sit any where in the room and know one has ever commented about hot spots and I've tried every angle and the picture looks great. The cone is not that narrow with this screen. Check out the Draper web site...the gain is still at about 2.0 at 20 degree off access. After looking at the High power Dalite I can verify that 20 degree claim. The High power's cone drops off very fast when you move off access and it is annoyong when walking across the room since my head will pass just below the projector when doing so. The M2500 gain looks the same at 15 feet from the screen and walking from one side of the room to the other in a 13 foot wide room. That says a lot!


Ron
 

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Quote:
Originally posted by mickster
One other question. Will I lose black levels by going with a higher gain screen?
Well, the answer for this question is "yes" (if two screens have the same size). But:


1. For the room with total light control (which includes dark ceiling, walls and floor), the picture's contrast is the same for low and high gain screens, as white also be higher and ratio white/black remains the same.


2. Depending on personal taste, high absolute level of black might be an issue (even if picture contrast remains the same). But visually the black levels gain from M1300 to Brilliant White is not noticable even for dark scenes (as eyes and brain adapt to the black level), so if black levels on BW will bother you, the same would be with M1300. Then you may use ND filter to adjust black levels to your taste, as PCARACER suggested.


3. Dim too bright picture is question of $20 - ND filter. Brighten too dim picture - question of $XXX, $XXXX or even $XXXXX - screen replacement, setup change, projector's replacement.
 

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Quote:
Originally posted by Ronomy
I have a 120 inch diagonal M2500 and I can walk right up to the screen and no hot spotting. I'm projecting at 19 feet from the screen though.


The M2500 has a very smooth transition of gain as you move off access so yes you will see a slight drop off in brightness* from one side of the screen to the other when sitting way off access like 40 degree to one side.
Ron,

The slight drop off in the visible brightness the most likley means pretty large difference in numbers (logarithmic sensitivity of human's eyes). For example, in my setup with SilverStar (103" diagonal, 90" width, 14' throw, 8.5' distance from the screen to the first row, watching from the side seat, viewing angle is about 41 degrees) I have no visible brightness drop from one side of the screen to another side. But measurements say there is about 1.7 times drop off**.

Added later.


You may do simple experiment: put uniform 70% IRA grey to all screen (e.g. from calibration DVD), make a screenshot with digital camera from the side (se sure that exposure time long enough to get average over image scanning - set high aperture and use tripod), download to a computer, convert to grayscale (discard color information) and measure difference between the brightest and darkest regions (e.g. with PhotoShop). In such way you may roughly estimate numbers of brigntess drop. Of course, the precision is far from the video photometer one, but is enough for the rough estimate.


Be sure that brightest region values are in range about 190..220 (of 256 levels). If they are lower you loose even that precision you may have (pretty poor already). If they are higher, you are in the risk to go to non-linear part of CCD sensitivity (crushing whites), which leads to the totally wrong results. It is good idea to make few sceeenshots with different exposure times and pick one with brightest area closest to 200 level.




* Highlighted by ehScorpio

** Measured with video photometer
 

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EhScorpio,


I agree with what you say...in fact white field uniformity with LCD projectors is not perfect either so selecting a point in photoshop can be all over the map when you factor the screen into the equation.


I'm just saying compared to the High Power Dalite the drop off is gradual with the M2500. That means you really don't see hot spots as you said...at least I don't see any and know one else at my house see's them.


With my setup I'm within the 20 degree cone at 15 feet back from the screen and because of the long throw, the angle or cone of light from the projector to each side of the screen is small compared to the center of the screen. Sitting down I'm at about 13 degree or a little less with a ceiling mount. Sitting or standing I see no change as with the High Power it is blinding standing up. I don't care for that shift...your eyes have to re-adjust. With a short throw and angular reflective screen I can see the angles would be much higher between the center of the screen and the side of the screen thus a narrow hot spot would show up.


The High Power would be better for short throw distances I would think...I just don't have experience with the short throw setup and large screen size.


My statement about walking up to the screen was over exagerated. Yes at that close range there is a hot spot but it tends to be right where my head is blocking the light from the projector so its hard to tell it is a hot spot. If I stand to the side and shine a light from the side of the screen, yes I see a hot spot. Under normal use I don't see any...even with a 0 IRE screen. My LCD does have a dark grey black level and if there is hot spotting I will see it as a higher level grey. I just don't see it! Angular refective screens with a long throw work quite well.


Ron
 

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Quote:
Originally posted by Ronomy
In fact white field uniformity with LCD projectors is not perfect either so selecting a point in photoshop can be all over the map when you factor the screen into the equation.
If non-uniformity is less than ~10%, you may ignore it taking into account that drop's difference will be much larger. If you suspect that non-uniformity makes good portion of the drop, make a screenshot from the other side of the center line (in this situation non-uniformity will work in opposite way) and calculate average drop before taking the ratio.

Quote:
Originally posted by Ronomy
I'm just saying compared to the High Power Dalite the drop off is gradual with the M2500.
I don't argue with this, but I had suggested neither High Power nor M2500 for Mick's setup. Please see my posts. And the primary reasons are:

- picture will be very bright and black levels will be high;

- brightness drop-off will be visible for angles in his setup.

Quote:
Originally posted by Ronomy
With my setup I'm within the 20 degree cone
And Mick's setup has up to 46 degrees cone...
 

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I use a ND filter to drop the brightness watching movies with the lights off so I can adjust output on the screen with filters. Works great since I can turn on the lights and watch without the ND filters and have a nice bright screen. That's the advantage of a high gain screen even if you don't need it for light controlled viewing.


If my front row is 10.14 feet from the 120 inch screen that would be about the same as what Mick has with his 106 inch screen at 9 feet.


First of all DVD's will not look that great at 10 feet and screen door will be obvious. Who cares about the front row...I would not govern my selection of screen, except maybe a smaller screen, if I had to sit that close.


I'll experiment tonight with 10 feet and see if there is any hot spotting visible. Sure measurable but does it standout by eye? My guess is there will be some drop off and only the sides of the 16x9 screen will drop off but it should not be an exagerated spot. Mick is projecting from 17 feet so he has a fairly long throw. Long throw will enlarge the hot spot because the light to screen angle at the projector is minimized. The spot is basically larger than the screen so you don't see it. The closer the projector to the screen the smaller the hot spot if your viewing at the same distance. The larger the angle of projection at the projector lens means the reflected angle off the screen is greater back to the viewer from the edges of the screen. The light is reflected away from you towards the walls with an angular reflective screen. Short throw and large angular reflective screens would not work...in that case a High Power Retro screen at table height just behind and above you or right to one side of you would be best for that setup since the light is reflected back to you instead of towards the walls.


Ron
 

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Follow up on my observations!


Yes I see a hot spot...but like I said it is so minor visually that it's a non issue. Actually at 9 feet distance to a 120 inch diagonal screen I was surprised how well HDTV looked forget the hot spot. I never noticed it till this thread and I had to look hard for it.


Your right though! I do see it...I can see with a short throw it would probably shrink in size and be more noticable. The longer a throw the better.
 
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