Can you give me a guestimate of what is the maximum ANSI contrast I can achieve in the following room ?


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The carpet is not as white as it looks at the picture of the back of the room, it's more brown, as you can see at the picture of the fron-left side of the room.

Impossible to answer. What about light control? What PJ? What budget? The color scheme will certainly cause issues and will be a crippling factor.

Impossible to answer. What about light control? What PJ? What budget? The color scheme will certainly cause issues and will be a crippling factor.

Light control is full. Regarding the projector, I thought that the room will limit the ANSI contrast to some value, regardles of the projector used...

Light control is full. Regarding the projector, I thought that the room will limit the ANSI contrast to some value, regardles of the projector used...

Thats true but some machines are very low to start with and the room may not be the limiting factor if you have full light control. Those colors are a killer, can you not darken at all? Just a bit? Also the blinds look as if theyd let some light in during the day, there a 100% sealed types available, I use the japanese Shyzip automated ones.

I once had a light room but darkened just the screen wall and the difference was huge.

As an aside and not in any way being critical, if your surrounds need to be positioned where they are and cant be moved to a better position, it may be worth having a look for a set of dipoles.

PS i put a response to your ANSI question in the other thread. Hope it helps.

The projector currently running in this room is the Mitsubishi HC3100, which is a Darkchip3 DLP unit.

Well you need to change the room. I dont know the potential calibrated ANSI of that unit is, but it will be almost certainly higher that the room can handle. Just checked and your unit, properly adjusted is capable of around 500/1 ANSI.

Do you think that treating the screen wall, and the first 3-4 feet from the screen towards the room (ceiling, side walls and floor), with black velvet, can make dramatic difference ?

In a one word answer...... YES

Thanks coldmachine.

Do it, baby.

Display a white field - and look around your room. any surface area much brighter than the rest - darken it. This can greatly improve your ANSI. It very much depends on your screen - you would prefer a grey gain screen rather than a matte white in such a room.

check out my post, i got the same projector, your room is gonna kill your ansi

http://www.avsforum.com/avs-vb/showthread.php?t=893495

Can you give me a guestimate of what is the maximum ANSI contrast I can achieve in the following room ?
I would guess around 40:1.

For comparison, my room has slightly darker walls, my front wall is 14 feet wide (168"), and my matte-white screen is 80" wide. I measured the maximum possible ANSI CR of my room & screen combo to be around 50:1. In other words, if I used a hypothetical projector that has infinite ANSI CR, the ANSI CR on the screen would be 50:1 because of room reflections. My projector has an ANSI CR of about 250:1, so the ANSI CR on the screen is around 42:1. If I used a wider screen, which would reduce the ratio of the room size to the screen size, then the maximum possible ANSI CR would be even lower than 50:1.

you'd need a 3000lumens light canon with great native contrast ratio and ansi ratio.

problem is close by side and ceiling wall.

or a Mirage screen which is designed for white rooms. it dramaticly increase the brigthness and contrast ratio. but it's around $4000

I would guess around 40:1.
Holy cow!. This explains why nothing seems to pop of the screen at bright scenes, everything looks dull. Darker scenes are much better.

you'd need a 3000lumens light canon with great native contrast ratio and ansi ratio.

problem is close by side and ceiling wall.

or a Mirage screen which is designed for white rooms. it dramaticly increase the brigthness and contrast ratio. but it's around $4000

But don't you think that treating the first 3-4 feet of the room with black velvet will be good enough ?. If I'm at 40:1 now, where will I be more or less after doing it ?

Your room is very theater unfriendly. Hardwood floor, white ceiling and light blue walls.
He is right with his estimated 40:1. I always say those who rush to buy DLP for its ansi with such room setting are wasting their time and energy.
With dark and absorbant material you get close to your pj native ansi but without measurement in actuall field it would be hard to give you any meaningfull number.

Just go with medium color or darker and black ceiling and you will be in happy you did. That would be the most cost effective measuable upgrade to your viewing experience imo.

Hi Jones!
I recently blackened most of my ceiling by tacking up black foam core to the ceiling. It took about a half hour and isn't permanent. In my case, it was easy to do because the ceiling is a low-basement ceiling.

But, the change from white ceiling tile to black foam core (which is still surprisingly reflective) has made a dramatic difference. And when I say "dramatic", I mean "well worth the effort." So, like the rest of the gang here, I suggest getting creative with dark carpets, and lots of wall treatments and ceiling treatments. Of course, if you're "allowed", get a power painter with some black paint and get jiggy with it.

Holy cow!. This explains why nothing seems to pop of the screen at bright scenes, everything looks dull. Darker scenes are much better.



But don't you think that treating the first 3-4 feet of the room with black velvet will be good enough ?. If I'm at 40:1 now, where will I be more or less after doing it ?


i meant without touching the walls. of course dark painting or even better for side walls, heavy dark curtains and for ceiling non reflective paint is better.

i'd say first 5feets

Thanks everyone.

A cheap way to demonstrate the change to yourself is to obtain several queens or king size, black, flat bedsheets. Tape them to your rear wall and the walls near your screen. Attach a string to them so you can sit at your chair and use the strings to "deactivate" your black panels while viewing the screen. Once you have been convinced (and I think you will be floored), then go on to a more permanent method or darkening the surfaces.

A cheap way to demonstrate the change to yourself is to obtain several queens or king size, black, flat bedsheets. Tape them to your rear wall and the walls near your screen. Attach a string to them so you can sit at your chair and use the strings to "deactivate" your black panels while viewing the screen. Once you have been convinced (and I think you will be floored), then go on to a more permanent method or darkening the surfaces.

Sage advice indeed.:D

I have made a measurement in my theatre of this. The room is 14 ft by 23 ft with the screen on one end. The walls are light coloured and the ceiling is white and stippled while the floor has fairly dark carpet. The screen is a 110" diagonal 16x9 format Stewart Greyhawk RS with the top of the visible screen about 8 inches from the ceiling and each side is 3 ft from the wall. I measured the light intensity with a meter at the centre of the screen and facing the projector (i.e. facing out into the room) and then took another reading while holding a small disk between the projector and the meter so that a small shadow was cast over the meter and it was reading only light reflected back from the room. The ratio of the light directly from the projector to that from the room was 55:1. The complete screen was illuminated at 100 IRE for this test (although the ratio is unaffected by the illumination level). This result is similar to Eric Garci's guess of 40:1. In my room, most of one side is occupied by an entertainment unit and shelf units, so that side will have reduced reflections.

I had tried the dark sheet approach mentioned above in front of the back wall, but that seemed to have no effect. Thus the light is being reflected mainly from the ceiling and to a lesser extent from the side walls.

This means that if I put up a checkerboard pattern for an ANSI contrast test that even perfect projector would be limited to 110:1 by the room (remember only half of the screen would be illuminated during that test).

Al

Here is the easiest way I have found to test your room (if your PJ mounting allows).

Project a bright scene. Pure white is best. Block half the lens, or move the PJ so that the image is only projecting on half of the screen.

If you can see the other half, ask yourself why?

In a good room, when you block the projected image from half the screen it gets so black as to blend into the screen frame. Any less is killing your blacks.

Have FUN!