DOF and Cropping take 2

Started 6 months ago | Discussions thread
awaldram
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Re: DOF and Cropping take 2
In reply to awaldram, 6 months ago

Let break it down even further

DoF and Focal Length is an inverse Quadratic.

As you increase focal length so magnification increased therefore fairly obvious as we know the entry pupil is as viewed through the front of the lens that if we double focal length then for the same F number the physical aperture is doubled.

So for the same F number at the same Magnification you have the same DoF.

so if you shoot 50mm f2.8 at 10ft then walk 40ft away and shoot the same target with 200 F2.8 then DoF and image will be identical.

I suggest you read

http://groups.csail.mit.edu/graphics/classes/CompPhoto06/html/lecturenotes/22_DepthDefocus_6.pdf

which is the lecture notes for courses 6.098 (Digital and computational Photography) and 6.882 (Advanced Computational Photography) MIT-EECs

or are you now going to say

Cambridge in colour are wrong

Luminous Landscapes are wrong

I'm wrong James is wrong and the Massachusetts Institute of Technology is wrong as well !!

Do you not think maybe they are not ?

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