Epson 3800 projector distance calculator - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 
Thread Tools
post #1 of 6 Old 11-05-2019, 06:22 AM - Thread Starter
AVS Forum Special Member
 
genaccmiller's Avatar
 
Join Date: Oct 2012
Posts: 1,200
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 647 Post(s)
Liked: 84
Epson 3800 projector distance calculator

Folks - I am a bit unclear on this topic and need some help. My room front to back is 185 inches. In the front I will lose 24.5 inches due to the construction of an Accoustically transparent screen wall. The Epson 3800 dimension is 13 inches depth. If I add another 4 inches to that for wiring there will be 17 inches from the back wall to the front of projector lens. So subtracting this as well as the previous 24.5 from 185 gives me 143.5 inches from front of projector lens to screen. Is this sufficient to produce a 120 inch diagonal 16:9 image? The results from Projector central are attached and it looks like I could theoretically go to 124 inches. This is for a 1.1 gain silver ticket screen. Why does the result show an estimated brightness of 77fl? Is this bad?
@noob00224

Sent from my Moto G (5) Plus using Tapatalk
genaccmiller is online now  
Sponsored Links
Advertisement
 
post #2 of 6 Old 11-05-2019, 06:53 AM
Advanced Member
 
Join Date: Jul 2017
Posts: 953
Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 491 Post(s)
Liked: 149
Width of an 120" screen is 104.6".
Minimum throw range is x1.32.
104.6x1.32=138.072‬"

Distance from screen to projector lens can be up to 143.5".
So it can be placed with the lens between 138" and 143.5".
Placed at 138" 100% of zoom is used. If placed at a longer distance, the zoom can be decreased.

Screen square surface is 42.71 ft².

In this review, the lumen values are measured depending on mode and lamp mode:
https://www.projectorcentral.com/Eps...s,-Connections

Lumen values in the review were taken with the lens zoomed at 100%.

From the review:
Bright Cinema in Eco lamp is 1683.
1683/42.71=39.4fL

Cinema in Eco lamp is 1204.
1204/42.71=28.19fL

These values are if a screen has a 1.0 gain. The ST actual gain may not be as advertised.

Quote:
Originally Posted by Dominic Chan View Post
They don’t have the Epson 4010, but using the 4040 the expected luminance is 34 fL. Also keep in mind the ST 1.1 gain screens measures closer to 0.9 gain, so the fL will be even lower.
Not sure if the screen Dominic is referring to is the regular or acoustic transparent one. Maybe ask in that thread, perhaps someone has measured the specific material you're interested in.

However, the difference between 0.9 and 1.1 is small with such a bright projector.
If the screen is actually 1.1 gain, then the brightness is increased by 10%. If it's 0.9, then the brightness is decreased by 10% as well.


15fL is recommended for SDR and 30+fL for HDR.
noob00224 is online now  
post #3 of 6 Old 11-05-2019, 10:57 AM - Thread Starter
AVS Forum Special Member
 
genaccmiller's Avatar
 
Join Date: Oct 2012
Posts: 1,200
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 647 Post(s)
Liked: 84
Quote:
Originally Posted by noob00224 View Post
Width of an 120" screen is 104.6".
Minimum throw range is x1.32.
104.6x1.32=138.072‬"

Distance from screen to projector lens can be up to 143.5".
So it can be placed with the lens between 138" and 143.5".
Placed at 138" 100% of zoom is used. If placed at a longer distance, the zoom can be decreased.

Screen square surface is 42.71 ft².

In this review, the lumen values are measured depending on mode and lamp mode:
https://www.projectorcentral.com/Eps...s,-Connections

Lumen values in the review were taken with the lens zoomed at 100%.

From the review:
Bright Cinema in Eco lamp is 1683.
1683/42.71=39.4fL

Cinema in Eco lamp is 1204.
1204/42.71=28.19fL

These values are if a screen has a 1.0 gain. The ST actual gain may not be as advertised.



Not sure if the screen Dominic is referring to is the regular or acoustic transparent one. Maybe ask in that thread, perhaps someone has measured the specific material you're interested in.

However, the difference between 0.9 and 1.1 is small with such a bright projector.
If the screen is actually 1.1 gain, then the brightness is increased by 10%. If it's 0.9, then the brightness is decreased by 10% as well.


15fL is recommended for SDR and 30+fL for HDR.
So essentially we are saying it would work.

Sent from my Moto G (5) Plus using Tapatalk
genaccmiller is online now  
Sponsored Links
Advertisement
 
post #4 of 6 Old 11-05-2019, 11:16 AM
Advanced Member
 
Join Date: Jul 2017
Posts: 953
Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 491 Post(s)
Liked: 149
Quote:
Originally Posted by genaccmiller View Post
So essentially we are saying it would work.

Sent from my Moto G (5) Plus using Tapatalk
Yes, but before mounting it try it on a table to see if the distance is ok.
noob00224 is online now  
post #5 of 6 Old 11-05-2019, 03:22 PM
AVS Forum Special Member
 
AV_Integrated's Avatar
 
Join Date: Jun 2005
Location: Northern, VA - Washington, DC
Posts: 6,629
Mentioned: 102 Post(s)
Tagged: 2 Thread(s)
Quoted: 1645 Post(s)
Liked: 1197
I'm not sure what confuses you.

THROW DISTANCE: 143"
IMAGE SIZE: 76"-124"

Is 120" between 76" and 124"?

Of course it is!

Yes, you are perfectly fine at that image size from that distance.

You read everything fine, and you can ignore the brightness claim. You can almost always adjust projector brightness way down to deal with whatever screen size you actually are working with.

AV Integrated - Theater, whole house audio, and technology installation in the Washington DC metro area.
AV_Integrated is offline  
post #6 of 6 Old 11-05-2019, 04:43 PM - Thread Starter
AVS Forum Special Member
 
genaccmiller's Avatar
 
Join Date: Oct 2012
Posts: 1,200
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 647 Post(s)
Liked: 84
Quote:
Originally Posted by AV_Integrated View Post
I'm not sure what confuses you.



THROW DISTANCE: 143"

IMAGE SIZE: 76"-124"



Is 120" between 76" and 124"?



Of course it is!



Yes, you are perfectly fine at that image size from that distance.



You read everything fine, and you can ignore the brightness claim. You can almost always adjust projector brightness way down to deal with whatever screen size you actually are working with.
Thank you. Was just getting nervous.

Sent from my Moto G (5) Plus using Tapatalk
genaccmiller is online now  
Sponsored Links
Advertisement
 
Reply Digital Projectors - Under $3,000 USD MSRP

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

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 Off
Pingbacks are Off
Refbacks are Off