# Front Projection screen size at 13ft?

Discussion in 'Archived Threads 2001-2004' started by Roger Kint, Dec 24, 2002.

1. ### Roger Kint Stunt Coordinator

Joined:
Jan 2, 2002
Messages:
161
0
At 13ft, what would be the image size from a front projector?

I have a 36" and it's kind of small from 13' away when watching DVDs.

2. ### Dave Getson Stunt Coordinator

Joined:
Nov 15, 2001
Messages:
167
0
What really determines screen size the throw distance. Some projectors have a short throw (larger screen in shorter distance from projector to screen) or a long throw (larger screen in farther distance from projector to screen). Each projector is different. Check out the calculator on www.projecorcentral.com. It will give you a size for 4:3 and 16:9 sized screens. It has the throw distance for just about any projector you can think of!

3. ### Brae Supporting Actor

Joined:
Jul 25, 2002
Messages:
509
0
Actually, I 'think' he is referring to the viewer being 13-feet from the screen and not the projector. You will find a typical 'rule of thumb' being that a screen width times 1.5 is your seating distance. Thus, 13' divided by 1.5 yields 104" screen width.
For a 16:9 screen with a 104" screen width the diagonal measurement would be about 119.3 inches. Of course, depending on the projector, lens, etc. the actual distance the projector is from the screen is an entirely different matter.
Additionally, you will want to consider the amount of light hitting the screen. If you go with a screen that is 13'/1.5 in width be prepared for major light-output requirements. Of course, all of this is based on what I 'think' you were posting about.

4. ### RayJK Stunt Coordinator

Joined:
Nov 25, 2002
Messages:
131
0
I'm 12' 8" away from my screen so I guess that is close enough to 13' to give an answer. My screen is the standard 92x52 105" diagonal and it is fine even when viewed from the second row of seats. I've sat at a friends house who had a 120" diag screen and that was too big at 13'. I kept having to move my focus all of the time and it was very tiring.

5. ### Brae Supporting Actor

Joined:
Jul 25, 2002
Messages:
509
0
RayJK, that's interesting that you found the 120" screen too big at 13'. In my quest for immersion, I find that 13' from a 120" screen to be the ,limit of far far away I wish to be from the screen.

I do understand that when THX conducted research and forward their model they took into account neck strain from a viewer in the primary viewing position having to move their head left & right in order to sweep the screen. They also measured the strain of eye fatigue under the same sweeping activities.

I find myself less suseptable to this kind of fatigue than, say, iris fatigue when a presentation has a lot of continuous bright/dark/bright scenes. Of course, those with very bright projection systems, RPTV with bias lighting, etc. can help reduce this type of fatigue, those CRTers and those digital projection users with calibrated units for maximum contrast are without this option.

I will also say that in my quest for immersion the aspect of a torus screen of sufficient magnitude is amazing. I good friend of mine has a DIY 120" 16:9 torus screen that is hard to describe, but I want one! Watching from an extreme off-axis was actually attainable and because of the shape of the screen (torus) no hot-spotting occured even though the gain was 3.1 (VuTec).

6. ### Robert James Clark Second Unit

Joined:
Oct 25, 2001
Messages:
353
1
I definitely agree that you should aim for a screen that should encompass, but not exceed, your field of vision.
It's that immersion effect that we are going for with front projection and what makes it truly a "home theater" and not just a big TV...

Joined:
Jul 6, 1999
Messages:
1,262
1

8. ### Gabriel_Lam Screenwriter

Joined:
Mar 7, 2002
Messages:
1,402
0
Let the nasty debates begin!!!
Hehe, kidding, kidding. No one string me up.
Like Brae, I've found a larger screen to be comfortable. At 13' the minimum THX recommended size (based on their optimal viewing angle of 36 degrees) is a 112.8" wide 16:9 screen. With a well set up torus, I'm guessing you can get away with more.

9. ### Alan Pummill Screenwriter

Joined:
Jul 6, 1999
Messages:
1,262
1
How cute, Gabriel.....

Joined:
Oct 25, 2001
Messages:
353
1

11. ### Alan Pummill Screenwriter

Joined:
Jul 6, 1999
Messages:
1,262
1
Peace be with you too, my friend!!

12. ### Parker Clack Schizophrenic Man Moderator

Joined:
Jun 30, 1997
Messages:
12,214
58
Location:
Kansas City, MO
Real Name:
Parker
I have always heard to use the 3 times the height or 2 times the width of the screen as the "rule of thumb" for screen size. (This is with a 4::3 screen). So if you have a 120 inch diagonal screen this would be a 6' x 8' frame and you would want to be back between 16 to 18 feet from the screen.

I had a 120 inch screen with my front projector and I set back about 18 foot and the picture was great. The whole time though I wanted to have a 9' x 12' screen because I like for the screen size to be more enveloping of my peripheral vision.

I personally have found that a front projected image that requires a little more use of my peripheral vision (as seen with a larger screen size) that my viewing experience is that much more enjoyable.

YMMV.

Parker

13. ### Brae Supporting Actor

Joined:
Jul 25, 2002
Messages:
509
0
Parker, I know what you mean about being enveloped somewhat beyond my peripheral vision. I think this is why I might still be seriously considering that torus screen and sitting no more than 13' from it with a 120" diagonal.
But, the original poster has not come back and offered any additional information so its hard to continue offering suggestions.