[Guest]

[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]



Not exactly.



Let's say you have the same 50mm f/5.6 lens from your example:



If you shoot with 1.5x crop sensor from 10 m distance, DOF is 11.3 m (so far so good).



However once you mount it on a FF camera, in order to fill the frame with exactly the same picture, you need to get closer to the subject by 1.5x factor.



And if you shoot with FF from ~6.7 m distance, DOF is ~7.5 m.