Hello Leica fans

Does any one of you know how to calcualte DOF. I mean I would like to programm this formula in a small calculator like a HP15C and just typ in aperture and distance and the calculator gives out the DOF range. Thanks for your help.

-- Salvatore Reitano (reitanosalvatore@hotmail.com), January 27, 2002

Answers

Yes, I'll give it a try.

If:

h = hyperfocal distance (in m) F = focal length (in mm) f = f stop c = circle of confusion (in mm): say 0.033mm nd = nearest distance of acceptable focus (in m) fd = furthest distance of acceptable focus (in m) df = depth of field (in m)

Hyperfocal distance is:

h = F^2 ÷ f ÷ c ÷ 1000 (F^2 means F squared)

Then:

nd = h × d ÷ (h + d)

fd = infinity (if d >= h)

fd = h × d ÷ (h - d) (if d < h)

df = fd - nd

I tried the thing with the programmable calculator when I had a Contax G (no DOF scales!), and found it to be a complete faff. That's one reason I've now got an M6TTL! Who knows though, it might work for you.

Anyway, best of luck with it.

-- Nigel Bowley (nigel.bowley@btinternet.com), January 27, 2002.

Many older photobooks came with DOF tables for the various focal lengths. You could also buy small pocketbooks or cards with the info as well. A quick look at card seems a great deal easier than carring a calculator. Here are some links to card sized DOF calculators:

http://www.konermann.net/dof.guide.html

http://fotosharp.safeshopper.com/4/4.htm?453

http://www.execpc.com/~gbonsack/dofad.htm

http://www.photocritique.net/dof.html

And some online DOF calculators:

http://www.outsight.com/hyperfocal.html

http://www.reftools.com/reftools/Arts/Photography/Photography.ht ml

http://www.johnhendry.com/gadget/dofcalc.htm

http://www.peternorquist.com/technotes/photo_calcs.html

http://www.dudak.baka.com/dofcalc.html

http://www.kaeri.re.kr/photo/lecture/hyperfocal.html

You might want to check out the FotoSharp Depth of Field Guide, (c) 1995 by Robert J. McCabe, available from KBR Enterprises, telephone(206) 248-1840. It has a depth of field guide for 35 mm format lenses from 20 mm to 100 mm in all of the popular focal lengths. It appears to use a fairly conservative CoC (I'd guess .025 mm). It is in a slide rule form, about 4" x 81/2", and includes an Action Stopping Shutter Speed Guide on the back side.

-- John Collier (jbcollier@powersurfr.com), January 27, 2002.

Sorry about the dead links, here they are again:

http://www.outsight.com/hyperfocal.html

http://www.reftools.com/reftools/Arts/Photography/Photography.ht ml

-- John Collier (jbcollier@powersurfr.com), January 27, 2002.

John is dead on. The Photosharp DOF calculator fits in your kit and is extremely helpful. Call John Mccabe, give him your VISA CARD (or other) and you will have your calculator within days. It is actually a slide rule and very easy to use. You will never leave home without it!! (8>))--Albert

-- Albert Knapp MD (albertknappmd@mac.com), January 27, 2002.

Nigel and John

Thanks very much for your help.

I am going to programm it now ...

Have a good week.

-- Salvatore Reitano (reitanosalvatore@hotmail.com), January 27, 2002.

This same topic came up just a few days ago on another Greenspun photo forum. I dug out my old Leica manual and had some luck with it. Here's the link. I'm not sure how well I explained it but the result I got was realistic. Let me know what you think.

-- Bob Fleischman (RFXMAIL@prodigy.net), January 27, 2002.

If you have a PALM, you can go to the PALM website and download a program that does the calculation for you (At least it was there a few years ago...) I don't bother with it personally, but know others who do. I instead use the dof scales on my lenses at one stop smaller than indicated, which effectively just reduces the value for CoC that I am willing to accept.

:) Cheers,

-- Jack Flesher (jbflesher@msn.com), January 28, 2002.

I use Bob Wheeler's Vade Mecum program on my Palm Pilot, and it's great when you need the extra features for view camera work and such. Sometimes, just having a table for a particular lens is handy, though.

I've extended an HTML DOF calculator written originally by Michael Gillett to handle f/1.4 through f/45. It handles multiple film sizes and uses different circle-of-confusion values for the different formats. Distances can be changed to fit your needs.

It's available on the "Other Resources" page of my regular site here if you want to try it and print out tables for your favorites.

-- Ralph Barker (rbarker@pacbell.net), January 28, 2002.

Here's the program at Palm: http://makeashorterlink.com/?I1672165

-- Duncan (airborn@euromail.se), January 28, 2002.

Here's a program for Windows that you can use on your computer (click and drag to set distance), or use it to print DOF calculators (circular slide rules) to take into the field: http://dfleming.ameranet.com/custom.html

Here's another Palm program: http://dfleming.ameranet.com/custom3.html

Both programs are free.

The equations for DOF and the theory underlying depth of field scales on lenses are here: http://dfleming.ameranet.com/theory.html

-- Don Fleming (drfleming@altavista.com), March 06, 2002.