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I recall this being discussed in great detail, but I cannot find it in the archives (after half an hour of searching).

How do you determine the slope required in an auditorium?

Here are the hypothetical auditoriums:

Cinema 1
45' long and 38' wide
130 seats (older style model, sloped)
35' screen maxed in scope
43' Throw

Cinema 2
37' long and 28' wide
70 seats (older style model, sloped)
25' screen maxed in scope
35' Throw

Please note that the throw assumes that the projector is set 1' away from the port within the booth, and the room length includes the 3' behind the screens.

Thanks for the help.

BUMP!

You might get with John Pytlak on this, Andrew. I think some of his papers deal with the subject, in one way or another.

3 feet seems pretty tight. Will you be able to service your speakers after the screens are installed?

[This message has been edited by rodeojack (edited December 23, 2006).]

You can request packets of info from any architects in the directories who specialize in theatre design. Also: lense manufacturing companies have nice little display charts for lense needed. Also: ask a seating company for a simple quote on seats and ask them for a sample drawing on theatres like this. Also: I believe Magna Tech makes a slide chart that computes all this. Bottom line: you have to see over heads, it's good to stagger a little if you can so you see between also, and there has to be room for the booth and the acreen can't be too high so they're craning

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Michael Hurley
Impresario

Mike,

Above the screen, as seen in the auditorium is masked by 1' and the screen's skirt is 4'.

This is all for my learning purposes, and I think its good to have in the archives for others.

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Since 1987

I have an article on cinema design.It doesn't calculate the slope but lets you know the distance that each eye sight line to the bottom of the screen should be above the average head height of the person in front. From memory I think it is about 10-15 cm. You can't always just go 15 cm though because the higher up the cinema slopes the more people look down at the screen which affects their sight line. The secret is to keep the stadium seats as low as you can say about 300mm so the stadium if it is really long the back rows are not too high. Each design though I beleive should be drawn to scale to have the sight lines checked. Each architect in my experience always has a different way of doing things and what is the riser for one architect could be different from another. For instance some cinemas also have riser height of 400mm.I haven't read the article for a while but if anybody would like a copy just let me know and I can try to get one to you.

I'd like a copy.

I know that 15cm is 6 inches (I live in Canada, so I know the metric system pretty well, but love many parts of the Imperial system), so is 300mm one single foot?

How can I get you a copy?

I’m putting on my fireproof suit for the flaming I’m gonna probably get for this, but are you sure you need a slope? When I went to beer and wine my insurance company had an opinion about me having drinking people navigating a sloped floor. The premium reflected that. So I tore out my slope, pushed the screen back a bit, raised it up a couple feet, and was very strategic about the placement of the seats. Been reopened since October and no complaints about sight lines. If I build another theater, I will seriously consider if I wanna do a sloped floor.
If you like VRs, hit this and move through the image with your mouse: http://nancyandgene.com/vrcorvallis/qtvr/avalon/avalon_theater_new/avalon_theater_new.htm

Avalon
If you wouldn't mind, what is the dimensions of the room pictured above including height?

SamCat-

Is this e-mailable or post?

Orephuem, the room is roughly 40x40. the ceiling is a bow truss that is 15' at the walls and goes to 21' in the center. I moved the screen to the corner to give more space and it actually improved the sound. I went with a digital projector in the room so throw is not too realivant, but will be reintoducing 35mm again when I get time. I put LED lighting under the tables between the seats to put a glow on the floor and keep it off the screen. The booths in the back are the big hit, second only to the sofas. A note about the floor: it's concrete. When i finished building my 4-plex i had about 25 gallons of paint. Rather than paying hazmat fees to dospose of it, we just Jackson Pollocked the floor with it, then sealed.

Avalon, thanks for posting the link to the pictures! I love your set up. It looks like it has a great authentic "art house" feel.

There is a difference on seat spacing with table involved and rows of seats
In each location local codes dictate the maximum slope or step height allowed for fixed seating
In Canada at least 35mm film can only be shown in venues with fixed seating (except for special occasion permits)
And since Andrew is in canada he would require an registered engineer and arch. for not only canada but mann.