What Screen gain to run??

Discussion in 'Projectors, Screens & Video Processors' started by Swiss-Steve, Dec 31, 2006.

  1. Swiss-Steve

    Swiss-Steve
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    Hi Everyone,
    Merry Christmas and Happy New Year to you all :cool:


    I am looking for a new screen material and woud like some advice from those with higher gain screens.

    I currently run a 1.1 gain screen material off eBay,
    16x9 screen width is 98 inches for my 9500LC.

    I am happy with this material, but want a little more punch, with out getting a hotspot.

    So what should I run??

    Would an increase of gain to 1.3 give me more?
    or should I look at 2.8??

    What are the other issues running higher gain??
    color shift off axis, narrow viewing cone.



    Appreciate your comments
    Cheers
    Steve
     
  2. Mad Mr H

    Mad Mr H
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    Hi Steve,

    I doubt 1.1 to 1.3 will make that much differance.

    Could it be that the room you are in needs some "darkening" treatment around the screen and the ceiling between PJ and Screen ???

    I have finally decided to go BLACK with my room, Originally I thought that a little to much but now as I watch in darkness at night the colour of ceiling and walls does not really matter.

    It will take me time to do this but the decision is made.

    I am suprised to hear a 9500LC needs help with brightness, The ones I have seen have all been OK, even in white rooms.......


    "color shift off axis, narrow viewing cone" are both reported by others as issues when using high gain screens, I have only ever used 1.3 gain screens or close.


    (Of course 6 tubes is brighter than 3 :D)
     
  3. Tom.W

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    Hi guys, I have both the stewart studio tek 1.3 and 1.5 gain screen's and I would highly recommend both . Any higher then 1.5 on a flat screen you risk hot spotting and color shift with CRT's . Stewart screens are expensive but you can find good buys on E bay .
     
  4. Tom.W

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    Oh I forgot .... HAPPY NEW YEAR ! :arty:
     
  5. Swiss-Steve

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    Thanks Andy and Tom,

    I don't have an issue with brightness really, it is plenty bright,
    but for daytime viewing I want it brighter without pushing the tubes.
    This is the reason I am looking for a screen with gain.

    But we just bought an appartment, so I am planning everything now.
    The living room where our HT is located,
    we don't think we would use a dedicated room often enough,

    The screen wall will be a dark red, but the rest will be light colored,
    we currently have all white, with a black screen wall.


    The new appartment has a full wall of glass which overlooks the Zurich lake, there is going to be shutters which will block out the light, so it should be pretty close to full blackout conditions during the evening.


    Cheers
    Steve
     
  6. Peter Parker

    Peter Parker
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    Grey screens with gain are the best option for ambient light conditions, but may not be your ideal screen for viewing in blackout conditions, so would you consider a pull down option for the grey screen so you could roll it up out of the way and then use the white screen for night time viewing (which could be either fixed or pull down)? Not sure how that would work out with the focussing though.

    Da-lite do a 1.1 gain grey screen which is similar to the Stewart FireHawk (but cheaper) and Optoma do a screen which is 1.8 gain and retro reflective but unless you are sitting with your viewing plane close to the projector, you won't get the full gain. Being RR it doesn't hotspot. Da-lite's Hi Power is a RR screen which is 2.8 gain so might work well, though doesn't combat ambient quite as well as a grey screen.

    Gary
     
  7. Swiss-Steve

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    Thanks Gary,
    I didn't think that running a grey screen with a CRT was recomended.

    The color temp would have be set for each screen type. Solvable with a recall setup.

    Focus would be an issue, but I think it could be solved, using the electronic focus adjustment. Have the correct focus for the white screen, then adjust it for the grey screen,
    would not be optimal, but no problem as the grey screen is not for HD Movie viewing.


    Next question, does anyone run a grey screen with their CRT????

    Hmmmm, something to think about.


    Cheers
    Steve
     
  8. Mad Mr H

    Mad Mr H
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    Hi Steve,

    I use a 1.3 gain screen. My Cinema room has windows/doors in one wall. I use blackout blinds over them.

    At night very dark room, During the day some light does get past them, BUT its VERY rare I am in there during the day to actually watch a movie.

    I think it almost more important to get the colours in the room better than White ceiling or cream walls......

    IF your screen takes up most ot the "screean wall" then maybe black for the rest of it does not look so bad, even in a living room.

    Wall paper in a tan/light brown looks very nice.

    Check out the "Home Cinema" section of this forum, some great rooms in there might give you some ideas........

    Whatever colours you paint or paper the room do tell us, this crops up often and I think is one of those areas were WAF usually has a high input........

    Thats why people go for a dedicated "Its MY room I will paint it MY colours :D " cinema room :smashin: .
     
  9. Alaric

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    Hi There,

    Mad - Black walls are a bit on the depressing side, even if its a dedicated boys room. We went for Kodak 18% grey - 6000N on the dulux paint machines IIRC (Gary ?). Its a darkish, but neuteral grey colour which fades to black when the lights are off....Far less dungeony. The ceiling is the the same colour and the carpet is a 3 tone shag pile black/dark grey/grey colour. The boxing/paneling is one of the ice storms which is a touch lighter than the 18%, but will eventualy have stone like dark speckle effect. The one concesion is some computer printed matt posters that we made as 'Window' like effects through the archways, however i got the wife to both slightly blur and mute the colours, which adds both a distance feel and stops any picture interferance.

    As for screen comments, i have a woven perferated screen so i'm probably nearer 0.8 than 1 even....However there are no windows in the room and we watch in darkness, even the kit is located ouside, and the PJ has a hush box, so ZERO external light....brightness is 40, contrast 60

    cya,
    Lee
     
  10. Mad Mr H

    Mad Mr H
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    I agree that an all black room might be depressing, I have my deep red seats and acoustic panels, the carpet is also a deep red.

    There is also an issue with an all black room - Your perception of things , Distance and persective, I have not had this issue myself but have heard people talk about it, an ALL black room though perfect might not actually be the ideal thing.......

    That said I doubt many (if any) rooms are actually BLACK BLACK.

    And I currently have Dulux "Ice Storm 1" waiting here, previously my from wall was "Ice storm 2" - 2 is actually fine for the front wall, what I actually want is to remove is the reflection from the walls, maybe fabric is the answer, BUT not sure about ataching it to the plaster !!! :eek: .
     
  11. acave

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    Russian Velvet from Dulux is a good colour to go. As for the Screen gain . . I don't think you can beat the Stewart 1.3 material for CRT. The overall image is just too good compared to other screens I've tried. Another thing to consider is with lower gains you run the tubes brighter to compensate. Is it worth it considering the cost of replacent tubes.

    Of course I say all this without having a CRT to watch for the last 5 weeks as installers are too busy lol.

    I purchased a new Stewart screen in the end for the above reason. The Vutec 1.3 screen material was good but I did not like the texture on the surface.
     
  12. Swiss-Steve

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    OK, I will give you a picture of how big this room is

    The screen wall is 6.62 meters long, with a 2.5m wide screen.
    This wall will be a Dark Red/burgandy color
    Black edge around the screen.
    On each side of the screen is my 6 foot tall Martin Logan Electrostatics.
    Martin Logan Electrostaic mounted under the screen.

    The Room width is 6 meters, with a ceiling height of 2.4 meters.
    The rest of the walls will possible be a light mushroom color,
    with a one shade lighter on the ceiling.


    Now this is what my Wife has come up with, which I am pretty happy with, as the dark screen wall is pretty much what we have now, except it is Black on the entire wall. The mushroom on the wall will be a lot better than white.


    I am now just trying to choose between the 1.3 or 1.5 gain Stewart screen.


    Appreciate your comments, keep them comming

    Cheers
    Steve
     
  13. Neal W

    Neal W
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    Hi Steve

    I too have a 9500lc with 1:1 screen on 80" width.
    Have played with the putting black felt material on ceiling and this gives massive difference in contrast ratio, its cheap to try and probably worth doing if your running a dedicated room.

    There are a couple of people who are all wise to 9500lc`s and both run draper m1300. one is a professional installer and the other runs crtprojectors (both have 9501`s), have discussed screen gain and apparently "a 1:1 screen will look rubbish on a 9501, you need 1.3 gain as anything else will give you hot spots".
    I really regret getting the 1:1 screen at all but bought a cheap screen before i move house and do a dedicated room, was a really bad move.

    Also G2`s on 9501`s are apparently particularly sensitive to getting a good picture, if your trying to preserve your tubes its worth making sure they’re set correctly. You could end up pushing the projector if these are set incorrectly and burn tubes early.

    Out of interest are your tubes in good nick? e.g. low hours
     
  14. Swiss-Steve

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    Tubes are pristine,
    about 1000hrs on them, no wear marks or masks.


    I currently have a ceiling mask which is about 400mm, really helps.
    Don't think that I will be able to do the same in the new appartment as the wall is so long.



    Cheers
    Steve
     
  15. Peter Parker

    Peter Parker
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    Many people think that a grey screen is just for low black level digitals to give them better blacks, but they've been around for a long time and they help subdue cross reflections and ambient light and improve ANSI contrast (though not on/off CR) in non light controlled environments due to the grey tone. Grey is the equivalent of white at a lower luminance, so unless the screen itself has a colour shift (some white screens do too, so it's not necessarily a 'grey' issue) it shouldn't be noticeably different unless you have a white screen as a reference. if you ever see a demo of a Stewart splitscreen with one side being Firehawk (measured at around 1.1 gain) and the other StudioTek 130 (1.3 gain) in a bright room with plenty of light, you will clearly see the advantages of a grey screen.

    I think most people would prefer a white screen given the choice, but greys do work very well with ambient.

    Good question. I think Jeff (now has a Ruby) used to use a Stewart Greyhawk screen with his Barco (?) IIRC, though I could be wrong. I'd certainly be interested to know if there are genuine CRT related issue with a white screen though I can't see why there would be off the top of my head.

    Hi Lee,

    Yes, I think it was me who got a Kodak 18% grey card colour matched by Duluxe for my walls with the 6000N being the colour code for it. Although it prevented any colour shift due to reflections, it still has a reflectance compared to material, so if you can use a cloth of some sort that would be better.

    I used black felt speaker cloth from Maplins going from the (black) screen wall to about 6ft into the room, so it covered the walls and ceiling, and it doubled my ANSI contrast due to greatly reduced reflections, so although the grey was OK for colour, it was not so good with black wash-out in mixed scenes. I can even notice the improvement over the grey carpet I have on the lower walls, so I wouldn't really consider anything other than black material for a dedicated room for my next theater.

    Having white walls with a CRT is very noticeable and detrimental compared to even a fixed pixel display with black walls, and the FPD will have better blacks in mixed scenes. I've seen the black level change luminance and colour as the scene changed due to the bright elements causing wash-out in the image. It was very noticeable with scope material as the top 'black' bar became lighter and bluer with a bright sky for example.

    Having black walls and ceiling near the screen give the impression of the image floating in space, and you have less visible distraction by not being able to see anything else other than the projected image. I know it's not really possible in a living room, but it does make a considerable difference in comparison.

    Gary.
     
  16. Gordon @ Convergent AV

    Gordon @ Convergent AV
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    I did three almost identical cinemas a few years ago. Each with the same SIM2 HT800 CRT projector. I spec'd the three different Stewart materials specifically so I could evaluate them in realife situation I can say that studiotek130 is my favourite followed by the 1.5 gain one. The 1.8 gain one has too rough a texture and shows too obvious hotspotting for me (the client likes it though as he likes his footy BRIGHT).

    By far the best way to gain more punch imho is as MMrH says...make the room really dark. Gary's idea of a grey high gain screen for daytime sports is also excelent but I think it could be problematic in practice with a non fixed pixel device. Perhaps a better solution is to just get a mental light canon fixed pixel thing for daytime sports then leave the Ultra for critical viewing in evenings

    Gordon
     
  17. Swiss-Steve

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    This is Great guy's, Keep the ideas comming :thumbsup:

    Gary,
    I understand what you are saying in regards to the Grey screen, BUT I don't think I can get past the idea that it should be white with CRT.
    Anyone have a big piece of Grey screen I could play with to see what it would look like??
    I had a piece of Firehawk, it was only 30cm x 20cm, but gave it away sometime ago.


    Gordon,
    could you comment a little more on the 1.5 gain screen.
    Could you see a hotspot? as this is my biggest concern.
    Is it a smooth screen?? or has some texture to it??




    Much Appreciated
    Cheers
    Steve
     
  18. Peter Parker

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    Grey screens help improve an image that is contaminated with ambient light. They give a better base black and subdue cross reflections giving better ANSI contrast. That's what the screen does regardless of the type of projector being shone on it. If there are any side effects for CRT I don't know but I don't see why it should be. You're probably thinking that grey screens are for fixed pixel displays with low on/off contrast, but although they do help there too, that isn't the only reason grey screens are around. Conference rooms have had ambient light issues for years.

    With any light in the room, your screen can only go as black as the lighting in the room will allow, so no matter how black you have your CRT set to go (even total fade to black), you will never get a good black because of the ambient in the room (your screen will only go as black as a dull white or grey). Your contrast will be dimished and has already been said, the only way to get contrast back is to then increase the white level or darken the room (and adjust the pj as necessary). If you want a more watchable image in those conditions (shadow detail for example), then a grey screen will improve it.

    You can see some good pictures here of just that here:

    http://www.avforums.com/forums/showpost.php?p=3644875&postcount=11


    I think given the choice, most people would prefer a white screen (since a grey screen is generally used for certain conditions and without those conditions their advantages are moot), and a high gain white screen does help reduce reflections onto the walls, (more is reflected towards the viewer or projector depending on if the screen is angular or retro reflective), so you then get less reflected back onto the screen, and light that does hit the screen from the walls will be reflected back more onto the walls than the viewer. It all depends on the viewing cone of the material, and generally the higher the gain the tighter the cone. It could work better if you set the black level higher so you have a daytime mode perhaps as well.

    If you want to have a better looking black with ambient light, you can use bias lighting to fool the eye into thinking the image is blacker than it is. The bias lighting (if done correctly) will cause the eye to adapt, closing down your iris and letting less light in, so the blacks look blacker. Again you may have to have a recalibrated black level setting so that shadow detail is more visible.

    Gary
     
  19. Alaric

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    Hi There,

    Gary - The screen wall is either screen or black speaker cloth as the whole wall is acoustic....My whole front sound stage is behind it so it was a necesity.

    The boxing & images are vaugely visible when a light scene is on the screen, but after spending so much time and effot creating the enviroment i doubt i'll change in to squeeze another ounce of picture quality out, as for me, the ballence between PQ and room asthetics is about as good as it gets. The room & decoration isn't fully completed, and has been ongoing for a year or two now, but still makes me go wow everytime I enter the room and that certainly enhances the expiriance if not the actual picture quality :thumbsup:

    Cya,
    Lee
     
  20. mrking

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    I should probably put up the gallery of the construction of my theatre.

    About 1000 pics of some crazy swedes putting alot of blood, sweat and tears into building a theatre.
    Anyways I used black out cloth for my walls and it is really the best way I know of getting your light controlled room black.

    The good part is that there is no reflection off this material so you will get a very nice ansi contrast in this room.

    Not sure if you have the same brand in the UK but it is called Molton. It's cheap too! About £10 per meter and each meter is 3 meters wide.
     
  21. Swiss-Steve

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    OK, lets throw another screen into the discussion,
    SILVER,
    or SilverStar as it is called.

    Is this something I should be looking into???

    Anyone had experience with a Silver screen and a CRT??????



    Appreciate any comments
    Cheers
    Steve
     
  22. acave

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    I had a sample of the Vutec silver material. I could pretty much run the CRT with the lights on :clap: but, that aint what it's all about for me.

    Hotspotting was a huge problem on this material. It sure was impressive at first. I'm still a Stewart 1.3 studiotek lover (as I've stated before).

    It might be worth your while getting samples as that is the only way you can decide for yourself.
     
  23. Peter Parker

    Peter Parker
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    I've got a sample of the SilverStar and it is indeed very reflective, so can give you the brightness you want at a larger screen size (I think the gain is more like 3:1 in reality). It may also be angular reflective so more suitable for ceiling mounted projectors.

    The only thing I noticed with it was that sometimes the strcuture of the material was noticable. Admitted this was on a lamp projector that didn't really need any help, but you'd see that with the sample if you get one.

    The other thing is that it comes as a complete screen - you don't get a frame and material, but a complete assembly, so you have to be sure that it can be brought in and manouvered around the house to where you want it to go.

    Gary
     

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