DOF CALCUALTION

[salvatore]

Hello Leica fans

 

<p>

 

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.

[nigel_bowley]

Yes, I'll give it a try.

 

<p>

 

If:

 

<p>

 

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)

 

<p>

 

Hyperfocal distance is:

 

<p>

 

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

 

<p>

 

Then:

 

<p>

 

nd = h × d ÷ (h + d)

 

<p>

 

fd = infinity (if d >= h)

 

<p>

 

fd = h × d ÷ (h - d) (if d < h)

 

<p>

 

df = fd - nd

 

<p>

 

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.

 

<p>

 

Anyway, best of luck with it.

[john_collier5]

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:

 

<p>

 

<a href="http://www.konermann.net/dof.guide.html">

http://www.konermann.net/dof.guide.html</a>

 

<p>

 

<a href="http://fotosharp.safeshopper.com/4/4.htm?453">

http://fotosharp.safeshopper.com/4/4.htm?453</a>

 

<p>

 

<a href="http://www.execpc.com/~gbonsack/dofad.htm">

http://www.execpc.com/~gbonsack/dofad.htm</a>

 

<p>

 

<a href="http://www.photocritique.net/dof.html">

http://www.photocritique.net/dof.html</a>

 

<p>

 

And some online DOF calculators:

 

<p>

 

<a href="http://www.outsight.com/hyperfocal.htmlk">

http://www.outsight.com/hyperfocal.html</a>

 

<p>

 

<a

href="hhttp://www.reftools.com/reftools/Arts/Photography/Photogr

aphy.html">

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

ml</a>

 

<p>

 

<a href="http://www.johnhendry.com/gadget/dofcalc.htm">

http://www.johnhendry.com/gadget/dofcalc.htm</a>

 

<p>

 

<a

href="http://www.peternorquist.com/technotes/photo_calcs.html"

>

http://www.peternorquist.com/technotes/photo_calcs.html</a>

 

<p>

 

<a href="http://www.dudak.baka.com/dofcalc.html">

http://www.dudak.baka.com/dofcalc.html</a>

 

<p>

 

<a href="http://www.kaeri.re.kr/photo/lecture/hyperfocal.html">

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

 

<p>

 

You might want to check out the FotoSharp Depth of Field Guide,

© 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_collier5]

Sorry about the dead links, here they are again:

 

<p>

 

<a href="http://www.outsight.com/hyperfocal.html">

http://www.outsight.com/hyperfocal.html</a>

 

<p>

 

<a

href="http://www.reftools.com/reftools/Arts/Photography/Photogra

phy.html">

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

ml</a>

[albert knapp md]

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

[salvatore]

Nigel and John

 

<p>

 

Thanks very much for your help.

 

<p>

 

I am going to programm it now ...

 

<p>

 

Have a good week.

[Rob F.]

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. <a href="http://www.greenspun.com/bboard/q-and-a-fetch-msg.tcl?

msg_id=007mIL">Here's the link<a/>. I'm not sure how well I

explained it but the result I got was realistic. Let me know what

you think.

[jackflesher]

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.

 

<p>

 

:) Cheers,

[ralph_barker]

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.

 

<p>

 

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.

 

<p>

 

It's available on the "Other Resources" page of my regular site <a

href="http://www.rbarkerphoto.com/DOF2.html">here</a> if you want to

try it and print out tables for your favorites.

[duncan_mcmorrin2]

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

[don_fleming2]

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

 

<p>

 

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

 

<p>

 

Both programs are free.

 

<p>

 

The equations for DOF and the theory underlying depth of field scales

on lenses are here: http://dfleming.ameranet.com/theory.html