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Focus Breathing

Basil

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Focus Breathing is one of those things that I knew about, but never really paid attention to since it never really impacted my images, which generally shot with a single focus point. But with my recent foray into shooting using focus bracketing, then combining several images together in post, made me experience the effects of focus breathing first hand.


Fortunately, Photoshop has the capability to take these image, all with slightly different focal lengths, and normalize them so as to allow them to be stacked. But if you looks at this short video, I step through a series of images taken with my 85mm f/2 lens at f/5.6. No settings changed and the camera is on a tripod and not moved. No other setting changed from shot to shot other than the focus point on the coin.

 

DrEntropy

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Never had to contend with it but it makes sense with trying to digitally stack the images at different focal points. I would expect the shorter the focal length lens the less the effect, too.

The "old time" solution was to throw more light at it! If the lens aperture can be cranked down to ∱32 or 64, no problem!

Problem solved! ;):D
stack.jpg
 
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GregW

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I would think you'd notice breathing on a motion picture camera when they rack focus from one actor to another. If it happens, it's never bothered me.
 
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Basil

Basil

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I would think you'd notice breathing on a motion picture camera when they rack focus from one actor to another. If it happens, it's never bothered me.
I'm certainly no expert but I've read somewhere that Cinema lenses are constructed so that they control / or eliminate the problem of focus breathing which is why cinema lenses cast so much more.
 

DrEntropy

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IMHO, the issue never came up before. "Focus stacking" only became possible with digital image manipulation. As I posted above, the answer used to be "throw more light at it."
 
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