Originally posted by Volker76 no, no, no and very false. The depth of field for a 50mm on apsc or 'full frame' is completely the same.
This ^ leaves out just enough information to be misleading, IMO.
50mm on FF and 50mm on aps-c also delivers a completely different image, because the aps-c shot is 1.5x tighter. It's kinda moot to worry about DOF differences when the framing is radically different.
50mm f/2.8 on FF vs. 35mm f/2.8 on aps-c from the same position - there we have the same FOV, and the FF shot would have a bit over a stop less DOF (equiv to 35mm f/1.8 on aps-c.)
50mm f/2.8 FF == 35mm f/1.8 aps-c in terms of FOV and DOF.
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50mm f/2.8 FF on left, 35mm f/2.8 aps-c on right)
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---------- Post added 02-12-15 at 01:48 PM ----------
Originally posted by DeadJohn Last night I was talking to a professional whose work includes night landscapes. He often travels from NYC to national parks. He's using a FF camera (Nikon D800). He mentioned he uses a 70-200/f4 instead of f2.8 because of weight.
I get why you'd want to do that, but using f/4 zooms on D800 doesn't give you any or much IQ advantage over say a sigma or Pentax 50-150 f/2.8 on D7000/K5. You'll get more overall pixels, more lp/ph in the image, but you give up the noise advantage and additional DOF control.
I guess it's attractive if you want to just have one camera and want a lower-weight
option for it, and if that f4 zoom is awesome... but buying FF and then
only shooting f4 zooms with it is not taking full advantage of what you bought, IMO.