AVForums.com is the UK's biggest & best home consumer electronics discussion resource New to AVForums.com? Start by reading our introduction here.


Go Back   AVForums.com > Video Electronics > Projection Screens

Reply
 
LinkBack Thread Tools Display Modes
Old 30-08-2004, 10:51 AM   #1 (permalink)
Member
Join Date: Apr 2004
Location: Peterborough
Posts: 248
iTrader: (12)
Thanks: Gave 0, Got 0
Grey or White. What screen is right for me?

After being blown away during a recent demo, I have ordered an InFocus 4805 projector. The projector will be ceiling mounted, but I have yet to decide if I should mount it length ways down the room, or width ways.

My room is 5 metres by 3 metres, and I have calculated (using projector central), that I would either be projecting a 200 x 112cm image length ways, or 160 x 90cm width ways.

To be honest, I think 200 x 112cm is too big for the room. My wife won't let me move the projector any closer to the screen because it will creep towards the middle of the room, which she's not happy about.

The width ways option, means that the projector will have to go far back to the wall (which is good from the wife's perception), and even then I will only be able to acheive 160 x 90cm with maximum zoom, which I know beacuse the light is dispersed more, is not an ideal situation. However, I'm hoping that given it's a relatively small image, it won't affect image quality to much? Any views on this?

Secondly, and perhaps more importantly, the projector will be used during the day (sky broadcasts) as well as the evening and although I have blinds covering the windows, there is some light creepage around the sides. From an aesthetics stand point, the wife won't let me go to any further measures to block out ambient light. Given the relatively low lumens output of this projector (750 lumens), I am concerned that the image will be a total washout. Is this a good reason to go for the smaller width ways through? I guess it would help?

Anyway, I plan to have a play with the projector when it arrives to determine exactly how unwatchable the picture might be, and then order a screen.

From what I understand on other posts, I might benefit from either a grey screen and/or a high gain screen. I have seen this one from Ellie (grey advantage electric for £462.46 160x90, or £514.40 200x112)

http://www.ellie.co.uk/acatalog/advantrange.html

Although it doesn't say what the gain of the grey material is (the normal white material is 1.2 I think), would this be a good choice? Apart from the slightly off-whites, what are the other downsides to grey screens?

Failing that, I could go for a matt white or high gain white. Opinions on gain or screen manufacturers would be most welcome. My maximum budget for a motorised screen is £600

Thanks

Gary
galewis1 is offline  
Reply With Quote
Old 30-08-2004, 12:54 PM   #2 (permalink)
Senior Member
Join Date: Jan 2003
Location: New Crobuzon
Posts: 1,706
iTrader: (18)
Thanks: Gave 4, Got 43
A grey screen won't work for you in dim daylight as they have a gain of about .8 on average and you'll be lucky to see an image at all. Even the smallest amount of light will washout the picture so IMO you should go for as high a gain as you can get, providing you can sit within the recommended viewing cone of the screen material.

I found the best way was to get screen material samples from the manufacturers and test them in the room.
__________________
Mat
avanzato is offline  
Reply With Quote
Old 04-09-2004, 1:05 AM   #3 (permalink)
Distinguished Member
 
Gary Lightfoot's Avatar
Join Date: Apr 2001
Location: Surrey. UK.
Posts: 7,307
iTrader: (7)
Thanks: Gave 5, Got 303
The Da-Lite High Contrast Cinema Vision is a grey screen around 1.1 gain, and this would work quite well with ambient light. Grey screens neutralise the effects of ambient light and improve apparent contrast as well as black level. The best product in your situation would be the Stewart Firehawk (grey with 1.35 gain), but it's very expensive (more than your pj).

As avanzto says, a plain grey screen will be less than unity gain, so although it'll work in some respects, it'll reduce the lumens further.

High gain screens can work almost as well, as they tend to have a viewing 'cone' - more light is reflected back to the viewer than to the sides (so the image will look dimmer if viewed from the far left or right of the screen), so you get a brighter picture. They also reflect the ambient light back towards the window (for example)rather than the viewer due to the viewing cone effect. Blacks still look greyer than they should - your screen will only be as dark as the room will allow.

Grey screens may be harder to come by, so a higher gain white screen may be your best choice. It's a good idea to experiment first to see what works though - and you're right - a smaller screen size means a brighter picture. Halve the image, and you quadruple the brightness, and vice versa.

Here's an interesting link if you have a few hours to spare:

http://www.avsforum.com/avs-vb/showt...hreadid=240074

HTH

Gary.
__________________
My Old Home Theater
Basic Projector Calibration
Gary Lightfoot is offline  
Reply With Quote

Bookmarks

Tags
grey, screen, white


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


All times are GMT. The time now is 11:02 AM.

AV ForumsOptimised for Firefox.
RSS Feed
AVForums.com is owned and operated by M2N Limited.
Copyright © 2000-2008 M2N E. & O. E.
Global Gold
Web Hosting