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#1 Louis

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Posted 01 September 2005 - 01:08 PM

Hello. I will be shooting a short film this semester for film school and I have a choice between shooting with either an Eclair ACL and a CP-16, and I just read in the Professional Cameraman's Handbook that the shutter angles of each are not 180 (170 for the CP16 and 175 for the Eclair). My question is: is this common among 16mm cameras, and will that exposure difference be noticeable? The only light meters I have available to me are based on 180 degree angles, and I realize that it's only about 1/6 of a stop difference, but on a smaller format projected on a big screen, will that be a problem?

Edited by Louis, 01 September 2005 - 01:10 PM.

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#2 John Pytlak RIP

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Posted 01 September 2005 - 01:32 PM

Hello.  I will be shooting a short film this semester for film school and I have a choice between shooting with either an Eclair ACL and a CP-16, and I just read in the Professional Cameraman's Handbook that the shutter angles of each are not 180 (170 for the CP16 and 175 for the Eclair).  My question is: is this common among 16mm cameras, and will that exposure difference be noticeable?  The only light meters I have available to me are based on 180 degree angles, and I realize that it's only about 1/6 of a stop difference, but on a smaller format projected on a big screen, will that be a problem?

<{POST_SNAPBACK}>


A 1/6 stop difference is negligible for any camera original film. Color negative films are even more "forgiving" because of their latitude. You can always "tweek" your T-Stop to give a bit more exposure if your shutter is less than 180-degrees. The Kodak incident light exposure tables assume a 170-degree shutter (1/50 second exposure time):

http://www.kodak.com...t/h2/ilit.shtml
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#3 Preston Herrick

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Posted 01 September 2005 - 03:01 PM

If you're using a CP with the butterfly shaped shutter (It will either have the butterfly or moon shaped shutter), then rate your film 1/3 stop slower. In other words, when you set the ASA rating on your light meter, set it 1/3 stop slower than you would normally and then you can forget about it.

Or, do what John suggests, and don't worry about it. A slight "overexposure" will give you a slightly denser negative with less grain. I've had telecine guys tell me 2/3 over works well for them.
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