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Discussion Starter · #1 ·
Every now and again, there's a thread about what is an appropriate riser height. Unfortunately, there is no one answer that covers all situations. Everyone's setup is different, and requires a different answer depending on many different variables. Here's a fairly easy formula to figure the exact minimum riser height for your setup.

Riser Calculator
Courtesy of trunks in Post #2


First, take the following measurements in the same increment (e.g. inches):


S=Floor to screen bottom

H1=Height of seated front row viewers top of head

E1=Height of seated rear row viewers eyes (no riser)

D1=Screen to front row viewers eyes

D2=Screen to back row viewers eyes


Then, plug them into these calculations:


H1-S=V1

V1/D1=R

R*D2=V2

V2+S=E2

E2-E1=Riser height


V1=Vertical 1, V2=Vertical 2, E2=Back row eye level (with riser).


This formula uses a single height viewer in both rows. If you think you'll have taller people in front and shorter people in back, you might want to adjust the numbers slightly to compensate. You will probably come up with a number that seems too high. It is not. This number is the minimum riser height that will allow a person seated in the back row to see the entire screen, over the head of a person seated directly in front of them. Anything less, and some of the screen will be blocked.


Happy Building!


Rob
 

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Rob -

I made a simple script based on this forumla.. I hope you don't mind.


thanks,

jake


Sorry, I didn't notice this domain had expired. Here's a new link:

 

http://calc.xn--f5a.net/
 

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Discussion Starter · #4 ·
Jake,


Great job! That is absolutely fantastic! Anyone else think that this should be a sticky? Moderators?


Rob
 

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That is definitely a keeper if it works! Hall of famer.
 

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Since I originated the particular discussion which resulted in showing the basic math followed by the helpful Riser Calculator, I'd like to see further adjustments, such as:

1. A variable number for the height of the seated rear row viewers eye

2. The picture actually changes as different variables are put into the calculator.

3. Assuming the height of the seated front row viewers eye is supposed to be 1/3 to 1/6 of the screen height, somehow add that.


Not being a programmer, it's easy for me to ask for something as complicated as this might become. In any event, nice work.


Sincerely, Take Aim
 

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Discussion Starter · #9 ·
Take Aim,


Regarding 1. above, you can use any height you want in the "front row viewers eye" space. It's actually the rear eye height that you need . I simply called it that because I used the same seats for both, and used the front seats to figure the eye height, before I actually had the rear seats. As for the other two, that's all Jake!


Rob
 

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Discussion Starter · #10 ·
Jake,


I realize now that my wording of the original formula might be confusing. If you agree, and would like to change the third line of your script to read "Height of rear row viewers eyes", with the tan line connecting the rear heads eyes to the top of the riser, I would change my original post as well. If not, I think people can figure it out.


Rob
 

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Quote:
Originally posted by robbyc30
Jake,


I realize now that my wording of the original formula might be confusing. If you agree, and would like to change the third line of your script to read "Height of rear row viewers eyes", with the tan line connecting the rear heads eyes to the top of the riser, I would change my original post as well. If not, I think people can figure it out.


Rob

Done

Quote:


2. The picture actually changes as different variables are put into the calculator.

3. Assuming the height of the seated front row viewers eye is supposed to be 1/3 to 1/6 of the screen height, somehow add that.

I thought about this a little more, and since the room isn't drawn to scale, the second request doesn't do a whole lot for us. Now the third option is a good idea, but I would also need the screen height (and probably the room height) to make it work.

What I would like to do is make a new calculator, this will be much more complex and take some time, but here are my ideas:


this will require room height, width, length. It will make a recommendation for number of riser levels, but allow the user to select how many they actually want (IE room size will allow for 3 riser levels, which script recommends, but user only actually wants 2 in room...) it will have defaults for several items, but all of course are user changeable: 4' riser for standard theater seats, 5' for nonreclining chairs/sofa, 6' for recliners (In my experience these approximate numbers usually work pretty good).

It will then give recommendations for riser height/placement, screen placement and maximum size (limited by riser visibility, or SMPTE/THX viewing angle for closest row)

Any recommendations? Hopefully I can have this done in a week or two (don't have a lot of free time)
 
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Quote:
Originally posted by trunks
Rob -

I made a simple script based on this forumla.. I hope you don't mind.


thanks,

jake

Riser Calculator

Very nice guys!


Just one comment.


The brown dimension line associated with the text "Height of rear row viewers eyes " are drawn showing the height of the FRONT row viewers eyes.


Larry
 

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Quote:
Originally posted by LarryChanin
Very nice guys!


Just one comment.


The brown dimension line associated with the text "Height of rear row viewers eyes " are drawn showing the height of the FRONT row viewers eyes.


Larry

Sorry, you must've been using it right as I was making the change. Should be fixed now.


-Jake
 

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robbyc30

Thank you for taking the time to post the formula


trunks

Thanks to you as well for writing the script so as to input info and get dimensions on the fly.


Best regards

Don
 

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Discussion Starter · #17 ·
You're very welcome. Glad to be of service. With so many people here, with so much great information, and giving such helpful advice, this makes me feel a little less like a mooch!


Rob
 

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Ok... I'm at work and don't have exact measurements in my brain, but that is just down right cool!!! Thanks!
 

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I spent lots of time before construction drawing sight lines etc... to be sure I got the riser height right.


I went and plugged in my numbers to compare with what I came up with in real life and your calculator was only one inch off of what I came up with for my riser.


I can see this being very helpful to everybody starting to plan their theater. Saves time.


Just make sure your eye, head height is the same as the defaults set here. Change them to be more accurate.


Very good job guys.


Jeff
 

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Very nice. I built my riser 10" high and my second row is about 3 inches to low. Your calculator says it should be 13-1/2".
 
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