Graflex.org

[SYNCHROJAMES]

My CG has a 135mm Graflex lens and a 6x7 roll back. Any one out there have an easy way to calculate hyperfocal distance?
Thanks, James

[Henry]

Well, Graphic Graflex Photography, 10th ed., defines hyperfocal distance "as that object distance on which the camera must be correctly focused in order that the far limit of the permissible depth of field shall just reach infinity" (PP. 43-44). This definition is followed by almost three pages of discussion, formulae, illustrative photos, and a table. From the table, I can tell you that, for your 135mm lens, the hyperfocal distances for each lens aperture are as follows: f4.5, 98 ft.; f5.6, 79 ft.; f8, 55 ft.; f11, 40 ft., f16, 28 ft.; f22, 20 ft. What I generally do, if and when I think about it at all, which is seldom, is predicated on the fact that as lens aperture decreases, depth of field increases (i.e., infinity moves "farther away"), therefore after focusing on the subject one can nudge the focus point a tad nearer the lens; the smaller the aperture, the bigger the "tad." If done right, everything on out to just infinity should be acceptably in focus, and objects closer to the lens which were formerly not in focus should now be acceptably in focus. I *think* that's how it works---that's my rule of thumb, FWIW.

Help us out here, gang!

[tsgrimm]

http://www.dofmaster.com/custom.html

This may help. If not, a web search for hyperfocal will bring up more than you may want to know.

[Henry]

To add to my previous post, again from Graphic Graflex Photography, p. 44: following the quoted definition given above is this: "Alternatively, if a camera is correctly focused on infinity,the hyperfocal distance becomes then the nearest distance that is just acceptably in focus....If a lens is correctly focused on its hyperfocal distance, then the far depth of field extends to infinity, as we have seen, and the near depth of field becomes just half the hyperfocal distance." Using the hyperfocal distances for a 135mm lens, as given by the table cited above, those respective near distances, in feet, for each f-stop from f4.5 to f22 would be 49, 39.5, 27.5, 20, 14, 10.