[Brightcolours]

[quote name='PuxaVida' timestamp='1286970603' post='3604']

...if only we're talking about fixing the FOV (size of object field) and comparing the DOF of cropped and FF bodies. I never had the chance to test it with a FF body but the readings regarding this show that it's the other way around. Let's say that we have a FF compatible 50mm lens and two bodies (FF & 1,5x cropped). The [url="http://www.dofmaster.com/dofjs.html"]DOF calculator[/url] gives following results:



FF + 50mm (F=5.6 and 10m distance from subject) --> DOF = 24,8 meters

1,5 Cropped + 50mm (F=5.6 and 10m distance from subject) --> DOF = 11,3 meters



But,



FF + 75mm (F=5.6 and 10m distance from subject) --> DOF = 6,58 meters (same FOV as in cropped 50mm, shallower DOF)



This relationship between focal length / sensor area / and field of view is very tricky.



Kind regards,



Serkan

[/quote]

It is very simple.



if you use 100mm and f2 on full frame, you need to use 100 / 1.6 and f2 / 1.6 (Canon) or 100 / 1.5 and f2 / 1.5 (on Nikon/Sony/Pentax) with APS-C to get the same field of view and the same DOF.



Nothing tricky about that... <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/cool.gif' class='bbc_emoticon' alt='' />



Problem is, that there is no 63mm f1.2 lens (Canon), no 67mm f1.3 lens (Nikon).



There is also no equivalent for a 85mm f1.8 (for Canon, the 50mm f1.2 comes close... but look at the price), a 85mm f1.4, a 85mm f1.2, a 50mm f1.4, a 50mm f1.2, a 35mm f1.4, a 24mm f1.4. Or even a 200mm f2.



So yes, of course you can get similar field of view/DOF combinations with APS-C and FF. But also, of course you can do things DOF wise you can not do with FF.



FF only is "important" if you are a photographer who actually uses shallow DOF.