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06-09-2013, 01:45 PM   #16
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QuoteOriginally posted by Bob from Aus Quote
So if you are still reading this confusing thread with all the mumbo jumbo the 35mm lens will provide a lot more depth of field compared with the 100mm. Why exactly is not really important.
Wow, so you call my post mumbo jumbo when I even linked to legitimate sources that explained exactly what I wrote? So how is the 35mm providing more DOF at the same magnification compared to the 100mm? I'm open to it.

06-09-2013, 01:49 PM   #17
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Here is a practical test: Theory - Depth of Field vs. Focal Length - Worth1000 Tutorials
06-10-2013, 05:45 PM   #18
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QuoteOriginally posted by Bob from Aus Quote
So if you are still reading this confusing thread with all the mumbo jumbo the 35mm lens will provide a lot more depth of field compared with the 100mm. Why exactly is not really important.
A 35mm has more depth of field at the same distance from a given subject. However, if you move closer to compensate for the difference in focal length, so the scene is framed the same, then the focal distance effect cancels out the focal length effect, and so for a given subject size in a given image, the DOF is independent of focal length, and depends only on aperture.
06-10-2013, 05:56 PM   #19
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QuoteOriginally posted by Kozlok Quote
A 35mm has more depth of field at the same distance from a given subject. However, if you move closer to compensate for the difference in focal length, so the scene is framed the same, then the focal distance effect cancels out the focal length effect, and so for a given subject size in a given image, the DOF is independent of focal length, and depends only on aperture.
Thanks - I have read a couple of articles since i first put the above comment down. It doesn't seem to fit in with my experience. I will do some tests, but I will try and work out the physics to get my head around it.

06-11-2013, 06:12 AM   #20
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I think we can cut through the technical information and focus on the important difference. 100mm is firmly in the telephoto range, and is going to be most useful at taking pictures of small subjects from a distance. This makes it perfect for insects and other critters which will take offense at a big object getting "up in thier grills." If you're more interested in a lens for museums, flowers, still life etc of fairly large items, the 35 is right for you (or another wider macro from other manufacturers).

I have a FA100 macro and a Sigma 28mm macro and use them for very different purposes.
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