DOF for 50D w/ EF 100-400mm lens w/ 1.4X Extender

Started Feb 28, 2010 | Discussions thread
Karl Gnter Wnsch Forum Pro • Posts: 11,408
Re: DOF for 50D w/ EF 100-400mm lens w/ 1.4X Extender

dukw_butter wrote:

However, my concern is that I have no way to tell the calculations whether the lens is an "EF-S" lens (designed for the smaller sensor) or an "EF" lens (designed for a 35mm sensor). Because the 100-400mm lens is an EF lens (designed for a 35mm sensor), I'm not clear that putting in 560mm as the focal length will get me the correct DOF results.

It simply doesn't matter if a lens is an EF or an EF-S lens as this only affects the size of the image circle but the focal length is a physical measure of a lens design irregardless of the size of the image circle or recording media, so a 17mm EF-S lens has the same focal length as a 17mm EF lens!
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regards
Karl Günter Wünsch

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Canon EOS 7D Mark II
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