[Cain]

I plan to get a Seleco HT300, and I'll assume it outputs 700 ANSI Lumens.


I plan to use a Stewart GrayHawk MicroPerf Screen.


I'll be sitting about 10-11 feet back (closer to 10).


What size 16:9 screen would you folks with similar projectors recommend??


I want the screen to be impressively large, but not so large I'm distracted by imperfections in source materials??


-- Cain

 

[aviman33]

I would recommend 80" wide for an XGA projector, however you should reconsider the micro-perf option. Some people on this forum have indicated it is not compatable with DLP projectors. Try searching the forum.




Jon

 

[DanHouck]

60 inches wide based on rule of thumb of optimum seating = 2 times screen width. You could go 72" with this projector because it is DLP, but I wouldn't exceed that IMO.


Dan

 

[Wireless]

I sit about 10.5 feet from an XGA DLP with an ISCO II and a 92" wide matte white screen. With the Selco you could go larger because of its greater pixel density and still not see screendoor, but 1.2 times screen width may be enough for even those nose against the screen aficionados (LiOn ). I'm getting 24 ft lambers at my size, plenty for a light controlled environment (only watch at night). I personally think you should go as large as you can while taking into consideration the resolution of the source. Of course I sit fairly close at the cinema as well.

 

[Chris Carollo]

I've got a 102" wide (DIY greyish) screen with my G15 & ATI HTPC setup, and I sit roughly 9' from the screen (so, roughtly 1 screen width away). On well-mastered material I see absolutely no artifacts from source material, on average source material I rarely see them, and poor masters are, well, poor. And I'm pretty picky.


I don't know how the screendoor from the DLP or microperfs compare to my setup, though, so YMMV.

 

[C Clark]

Quoting from a tech note I found at a web page called CinemaSource, based on a January 1986 issue of the SMPTE journal, the image should occupy >30 degree of the horizontal field of view (subtended viewing angle) or >15 degree of the vertical field of view.


A formula: Distance = Width/(2*tan(15)) or Width=Distance*2*tan(15)


This gives approximately the 2x factor stated by Dan (actually 1.866 but who's counting). So, 9'=>58"; 10'=>64"(~74" diag); 10.5'=>68".


Pixel structure may cuase you to want to sit further back, but that's a different issue. I'm planning on the 2x factor for my stuff which will be one of the new 16:9 DLPs.

 

[Cain]

Thanks for the thoughts gang.


Mr. Clark. Is it possible those calcs are incorrect??


There is no way a screen that small, at those distances will take 30 degrees of a field of view...


I'm gonna ask around, perhaps the numbers are set only for the vertical angle??



-- Cain

 

[JG]

Cain,


My advice is simple. Do not buy a screen until you have lived with your projector for a month or two. My theatre, with a LT-`150 projector has two seating positions. One at 9 l/2', the other at l5'. Initially I painted a 92" wide screen on the wall. Then seeking a more cinamatic experience, enlarged it to 96" and finally settled on l04" wide screen. I prefer the seating positon at l5' but my wife insists that the front row is much nicer. So you see, screen width and image size is a personal preference and cannot be determined by formulas and other's opinions. You must choose what you like best. A can of white paint and a little masking tape can go a long way in helping you choose the screen size that is right for you.


Jeff

 

[William Mapstone]

Cain


Those numbers are correct. A 30 deg field of view at 10' would require a 64" wide screen. Dont forget that this is a min. recommendation. I would recommend atleast a 40 deg field of view which would be 87" wide. Assuming that projector is the new 1280x720 dmd i think the 2x rule is being too concervative. I am running a 96" wide screen with a 1366x768 LCD at a 10' viewing distance, and YES i do see pixel structure but it is not that bad. I also have a set of seats at 14.5 feet which is more film like. If DLP does indeed have a larger fill facter than LCD then a 96" wide screen might (?) be tolerable for you.


Is it necessary to use the greyhawk on these new DLP's?

I'm thinking that it may not be nesasary if the blacks are improved.


William

 

[Cain]

Thanks again guys.


Jeff,


I plan to get the projector and spend at least a few days shining it on the wall to determine what size image we like best, before I buy a screen.


The only problem is this delays the start of my HT for a considerable period of time!!


William,


Good points, many thanks for the note, and the info.


I'm leaning strongly towards 96" wide, I guess I can always project smaller, then put curtains on the side if I think it is too large..


Yes I am told the new DLP's still benefit from a GrayHawk, to improve their black levels.


Take care guys,


-- Cain

 

[Wireless]

Another idea.


I went to a fabric store and bought some blackout fabric and Home Depot to pick up a couple of long 1x2s. Stapled the blackout fabric to the pieces of wood, cut the farbric to about 104" and hung it from hooks screwed into the wood. Less than $40 and gave me a better idea on what size screen to order.

 

[Gary P. Gibbs]

In terms of field of view:

My seating distance is 12.5' with a XGA DLP. I originally started with a 92" wide screen (1.6 distance to width), but recently changed to a 104" screen (~1.4:1). I am much happier with the new distance. I still can not see pixels at this setting. I would recommend trying different settings with either a sheet or such. You could also try different seating distances at a local theater and "step off" the width and distance to get a rough idea of what you like.


Brightness is another matter which depends on screen size and gain and projector output. for example I use a Hi Power Da lite now and probably could not get away with a low gain screen in my configuration. With a closer distance and smaller screen I could make out with a low gain screen. YMMV.

 

[Paul_Seng]

Why don't you trace corners of different size screens with a pencil. Sit back and look at the wall and see if it is too big or small. Try different sizes. At 10 foot back I have a 80 X 60 screen and it is fine for me.

 

[Augie]

To help with your 30 degree angle of view calculations. If you are prompted for a username and password, just click Cancel. The "30%" stated on the spreadsheet is a typo. It should be "30 degrees".

http://www.teamzim.com/augie/screen_...calculator.xls