Film-Tech Forum ARCHIVE: Lens Calculator

This is topic Lens Calculator in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Eric Womack (Member # 4458) on 07-25-2008, 04:12 PM:

Searching for a piece of software that will calculate image size, lens size based on throw distance and desired image size. Any one know where I can find that? i think there was one called lenscalc.exe.

Posted by Adam Martin (Member # 641) on 07-25-2008, 04:35 PM:

There are a couple right here on Film-Tech.

Posted by Eric Womack (Member # 4458) on 07-25-2008, 06:25 PM:

Thanks Adam.

Sooner or later I'll learn to not ask stupid questions and look a little more at this site and see before I make a fool out of myself

Posted by Galen Murphy-Fahlgren (Member # 4535) on 07-26-2008, 12:09 AM:

Neat. I was planning on writing one a few months ago, but never got around to it.

Posted by John Wilson (Member # 269) on 07-26-2008, 12:15 AM:

Here you go Galen. One of your very own.

Posted by Galen Murphy-Fahlgren (Member # 4535) on 07-26-2008, 02:28 PM:

I may have misrepresented myself. When I said I was planning on writing one, I meant I was planning on making my software engineer father do it. [Big Grin]

Posted by Galen Murphy-Fahlgren (Member # 4535) on 10-30-2008, 11:00 AM:

Does anyone know of an html based calculator? I run Mac, and am not particularly interested in booting power sucking Windows every time I want to use such a one. If not, I guess I will have to make my own. I'm looking for something pretty variable, so I can enter a couple of criteria (picture area, focal length, throw, projected image size) and have it produce the output I'm looking for.

Posted by Robert Minichino (Member # 3495) on 10-30-2008, 11:06 AM:

For what it's worth, the Schneider calculator works great with Wine on my Linux system.

Posted by Sean Weitzel (Member # 244) on 10-30-2008, 12:08 PM:

www.cssinc.com used to have a web based one last time I checked. The site currently appears to be down at present.

Posted by William T. Parr (Member # 677) on 10-30-2008, 02:41 PM:

I just got into the ccsinc website and used the calculator.

Posted by Galen Murphy-Fahlgren (Member # 4535) on 10-31-2008, 11:41 AM:

The CSS is exactly the sort of thing I'm looking for. I'd also like 16mm support, but that can wait until I get off my duff and make my father write one to my specifications. Thanks!

Posted by Scott Norwood (Member # 30) on 10-31-2008, 12:25 PM:

Alternative option: International Cine in Miami, FL sells a cardboard slide-rule lens calculator that covers pretty much every format known to man. It's not as sophisticated as the Schneider software, but it's easy to use and more convenient than carrying around a laptop (or doing the math by hand) at film festivals and similar events.

Another thing that I have done is memorize some common focal-length/throw distance/screen size combinations, since those can be easily re-used (e.g. doubling the throw distance without changing the lens will double the width and height, increasing the image by 4x).

Posted by John Hawkinson (Member # 1135) on 10-31-2008, 04:49 PM:

At that rate, Scott, someone should just make up a PDF file of a nice set of facts and nomographs and soforth. You could even do a sliding paper affair like Andy Kinsman (of Kodak!)'s PostScript slide rule (in PDF).

--jhawk

[ 10-31-2008, 07:44 PM: Message edited by: John Hawkinson ]