Hyperfocal distance and DOF experiment

[Ehcalum]

Try manual focusing on the hyperfocal distance using your distance scale. AF doesn't always hit the right spot.

[David Selby]

when you are hyperfocal distance focusing you are placing the focal point on a subject matter. What this means is that obviously there is DOF in front and behind your focal plane. However, the calculation alone will not gurantee perfections in the lens opticals and what you are doing is placing too much demand on the lens at that aperture.


I would have used live view if i were you, and then focused on the tree, this would help with focus to begin with.


I woul also stop down the lens to F/8 or F/11.





What you also need to realize is that, at the far ends of the DOF buffer, that resolution is lost you aren't resolving as much. However, when viewing the print "normally" the background trees appear as sharp and within the DOF.





I believe if you stopped down to F/8 or F/11 you would see a noticable increase in the resolved trees.





FOcus on car @ F/2.8








aperture down to 4.0








Aperture to 5.6








Aperture to 8








While my focus did not change at all, I left all of that stationary, I did stop down my apertures and you will see how the items in the rear are better resolved. However, you just can't expect that great of a performance at F/4.

[David Selby]

Also the following scenes are with the 17-40 L on an XSi


THe slices are full size and taken from images that look like this:











F/8





F/11





F/16








I believe this shows the other side of the Hyperfocal problem, where you resolve better at F/8 and the narrower you go, the more your image suffers from diffraction at 100% views.