Focal length + DOF

[teefin1]

Am I correct in assuming that a longer focal length with a larger F number can possibly effect equal or shallower DOF to shorter focal length/smaller F number?

(I.e 50mm 1.8 v 85mm 2.8)

 

[nianys]

It's taken me long to realize how much focal length has in fact MORE impact on compressing backgrounds and creating blur, than aperture itself. A 135/3.5 very easily totally erases backgrounds, sometimes more do than a 35/2, for instance. Distance to subject, and from subject to background, is also tremendously important.

 

[eno789]

Yes. See also: https://www.talkemount.com/f12/newbie-legacy-lens-question-1713/#post13502