Measuring Focus through a Mirror??

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#1 Doron Kipper

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Posted 14 February 2008 - 01:22 AM

I have a film camera without a reflex viewfinder...so I've had to resort to using a tape measure for my first film shoot at school to achieve sharp focus. How should I go about focusing on something in the reflection of a mirror? Should I measure the distance from the mirror to the object, and then from the mirror to the camera and add them together? or measure just to the mirror?
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Posted 14 February 2008 - 01:27 AM

I had to do this on a bolex once. If i recall correctly, I measured from the mirror to the camera. I was working at an F4 or so and It came out well enough (most people thought it was a window, not a mirror, though, but that's filmschool). Working at a higher stop will help, if you can (and you want to meter what's reflected in the mirror not just the mirror itself, obviously) as the DoF will help sharpen things if you're a bit off.
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#3 Satsuki Murashige

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Posted 14 February 2008 - 02:00 AM

I have a film camera without a reflex viewfinder...so I've had to resort to using a tape measure for my first film shoot at school to achieve sharp focus. How should I go about focusing on something in the reflection of a mirror? Should I measure the distance from the mirror to the object, and then from the mirror to the camera and add them together? or measure just to the mirror?

Your first instinct is correct - measure from the camera's focal plane to the mirror and then from the mirror to the object. The sum of the two measurements will be the correct distance for focus.
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