The sunny F-16 rule applied to motion picture cameras?

Robert86

Robert86

Carbonite Member
So I was reading a segment on exposing without a meter(still photography) and came up with a theory(I'm certain this has been thought up before) relating the sunny F-16 rule to the motion picture camera.
"The correct exposure is the number on the shutter speed dial closest to the film's ISO number, at F-16. Or, Exposure = 1/ISO @ f-16." For example, if I am shooting(w/ a still camera) 200 speed film, the correct exposure would be a shutter speed of 1/250 at F-16. Now I am going to try and apply this to the motion picture camera. This is where I need some kind of confirmation, a yes that is right or no that is WRONG.
Now since the normal shutter speed for a motion picture camera is 1/50sec(1/48 rounded off) at 24fps and that is all I am able to use with my camera, can the sunny F-16 rule be applied properly? Say I am shooting with my 16mm camera and using a 250 speed stock and I can only use a 1/50th shutter speed with my camera would my correct exposure(on a bright day outdoors) be around F-32? Every shutter speed up or down the scale equals an addition or loss of 1/3 of a stop. So, since going from the shutter speed 1/250sec(closest to speed of film) to 1/50sec(typical shutter speed on motion picture camera/only useable shutter speed) I would stop down 2 and 1/3 stops which brings me to F-7. Same with a stock at a speed of 50. I would use a 1/50sec shutter speed(closest to film speed) and open to F-16, since I didn't have to compensate for an adjustment of shutter speeds I would stay at F-16.
Does all that make sense? Is the sunny F-16 perfectly applicable to the motion picture camera? Thanks for reading and please let me know if this would be a correct assumption or not.
 
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If the rule works for still photogrpahy, it should work for motion picture photography, wherein you're simply exposing a series of individual stills.
 
That's what I figured. But is there nothing that would defy this rule for motion picture photography.
 
the theory is sound, your understanding of F-stops is not. At 24 fps the shutter speed is locked at 1/48, or a 50th for easy math. So the rule works for f16 using 50 asa stock. For 250 you would need to stop down at least 2 stops to f32, not open to f8. As most lenses don't go past f22, you'll need at least one stop of ND filter (.3). Yes to add to the confusion ND is a different calculation. The filters marked .3 are one stop, .6 equals 2 stops and .9 is 3. and if you use color correction you'll have to account for that.

Rule of the thumb until you have more experience, don't shoot 16mm without a decent light meter and an ASC manual, it's just too damn expensive to make mistakes.
 
Doh! That's what I meant, to close down some stops. So this rule, in theory, is perfectly applicable to a motion picture camera?
 
dop16mm said:
the theory is sound, your understanding of F-stops is not. At 24 fps the shutter speed is locked at 1/48, or a 50th for easy math. So the rule works for f16 using 50 asa stock. For 250 you would need to stop down at least 2 stops to f32, not open to f8. As most lenses don't go past f22, you'll need at least one stop of ND filter (.3). Yes to add to the confusion ND is a different calculation. The filters marked .3 are one stop, .6 equals 2 stops and .9 is 3. and if you use color correction you'll have to account for that.

Rule of the thumb until you have more experience, don't shoot 16mm without a decent light meter and an ASC manual, it's just too damn expensive to make mistakes.
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is the shutter angle not adjustable? just reduce the shutter angle for the same effect.
 
You are shooting film without a light meter?
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Yes. Although I plan to get one eventually, I do not want to become dependent on a light meter. My goal is to learn how to expose without the need of a light meter then once I can make better judgments on exposure I will use one, but the principle is to learn on my own first.
 
>I do not want to become dependent on a light meter

Don't let the producer hear you saying that!
 
... I do not want to become dependent on a light meter.
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Kids Say the Darndest things

kids_say2.jpg
http://www.seamovies.com/images/kids_say2.jpg
 
dop16mm said:
Rule of the thumb until you have more experience, don't shoot 16mm without a decent light meter and an ASC manual, it's just too damn expensive to make mistakes.
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Totally agree.
 
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