Originally posted by eddie1960 Sorry Jim that is only valid for FF
hyperfocal distance can be compared at the online DOF calculator (it likely won't be perfect but it'll give you the zone of focus pretty closely)
Online Depth of Field Calculator Logical experiment. With the same lens, if you aim your camera at a ruler lying on a table and take one photo with a FF camera and one with an APSC camera with the same settings (centre of ruler is the focus point and then it fades into bokeh in front and behind that). What you are in effect doing with the APSC is cropping out a smaller frame in the middle of the FF picture. So the absolute DOF will be the same in the two photos, right? I would be very surprised if the picture taken with the APSC had a shorter absolute DOF.
If there isn't something very fishy going on here the hyperfocal distance should not change because of capture format. Now I understand that circle of confusion might just be that fishy thing so I guess I should read up on the physics behind this to be sure.
Or then if someone with a nikon FF could just take the pics in the above mentioned experiment using the autocrop function the camera has and post them here.
Originally posted by sewebster The way I remember is to think that if I enlarge more (as will be the case with a crop sensor) then slightly OOF areas will be more obvious, reducing apparent DOF.
This is a very good way of thinking about it, makes it much more logical.
Think I might be getting a hang of CoC now. Will leave the above text standing though because I'd still want someone to take the pics and compare them, 1-0 to physics if there is actually a difference.