Depth of field/focus Question: FF vs. Crop

[tintinb]

I am a bit confused about this issue and hope someone can explain better.

I commonly hear that the crop body offers more dof to work with, which is an advantage of the crop body.

I can see that given the same focal-length lens, and the same subject (with a fixed dimension), the FF-body will be closer to the subject than the crop-body. (I am assuming we are looking for the same composition in frame, except for the perspective issue).

Now, if I placed the subject at the same distance from either body - will the crop body still have the dof advantage?

(I understand that by placing the subject at the same distance, I will not be utilizing all the pixels of the FFbody, that is not what I am concerned about).

I hope the following schematic diagram helps make my question easier to understand.

[LordV]

The DOF of a FF camera vs 1.6 crop is higher for the FF camera if the lens is the same and at the same focal length/magnification. If you use a longer focal length or higher magnification on the FF camera to get approx the same FOV as the 1.6 crop camera then the DOF will be slightly lower for the FF camera.

Liewwk has a useful macro DOF formula for macro here http://liewwk-macro.blogspot.com/2008/10/what-depth-of-field-dof-you-have-while.html

[tintinb]

The DOF of a FF camera vs 1.6 crop is higher for the FF camera if the lens is the same and at the same focal length/magnification. .....

Liewwk has a useful macro DOF formula for macro here http://liewwk-macro.blogspot.com/2008/10/what-depth-of-field-dof-you-have-while.html

Thanks Brian !! :)
You definitely should write a book .
The appropriate answer and so quick!


The .... If you use a longer focal length or higher magnification on the FF camera to get approx the same FOV as the 1.6 crop camera then the DOF will be slightly lower for the FF camera.


Will it be slightly lower or slightly higher?