Merhaba Bülent,
you're lucky because I can reduce your question :-)
I know there are a lot of threads about DOF here and some people are already tired of it, but never mind, here goes:
DOF of one given lens is exclusively (no other factors) determined by:
- FL focal length (independent of sensor size, FL is always the same)
- A aperture area divided by focal length (independent of sensor size, aperture = FL / aperture diameter), just like jfsavage pointed out already
- COC circle of confusion: the degree of acceptable sharpness/unsharpness (dependent on sensor size, full format COC ~ 0,03mm, APS-C COC ~ 0,02mm) This is actually the easiest way to describe magnification ratio and viewing distance in one simple number.
- distance to subject (obviously independent of sensor size)
So I have reduced your question to four factors. Please believe me, nothing else contributes to the DOF.
Common myths:
- special 'digital' 'reduced-sensor' lenses with different optics than 'fullformat' or 'film' lenses (the industry was quite successful with this myth, since so many people believe they have to buy 'digital' lenses)
- exposure differences due to that special lens design (it is only that lenses with a chip inside can tell the camera much better what is going on. Also, some non-chipped lenses use the contacts of the camera bayonet better/different than others)
I think the easiest to start with is the basic lens design, like focal length and aperture, and what is actually inside a lens.
That is quite simple after all.
Hope this was not too much of things that you already know,
Georg (the other)
PS: Nice article on
Digital Depth of Field (start at the end with points 1. - 5. )
.