DOF guide numbers for telephoto lenses

Discussion in 'General Technical Discussion' started by Rich Gibson, May 24, 2007.

  1. Recently Flew pm'd me with a back of the envelope figure of depth of field for a particular lens. It occurred to me that I had no idea how he got that. Is there some source on how to go about finding/calculating these figures? Now that I'm shooting more birds and can see the distance on the lens to the subject and the aperture it would be nice to have some cheat cheet...or handy formula...nah, make that a cheat sheet to see what DOF I can expect on the bird. I know I'm not allowing enough right now.

    Thanks, Rich
     
  2. You can find some in the Sigma site. For example, the one for your 120-300 is here.
     
  3. Excellent Phil. Thanks; that was quick. Even stupid questions are answered in this place! Is the Cafe great or what? And the moderators, not only good looking, but smart....well, some of them!

    Rich
     
  4. Bob Coutant

    Bob Coutant Moderator Moderator

    May 17, 2005
    Pleasantville Ohio
    from a non-super, non-moderator...

    if that's allowed:smile:.

    Rich, if you want to know more, download this small calculator (550k)from DL&C. You can use the calculator directly or, after reading the help file, construct a spreadsheet or perhaps enter the equations in your pocket calculator. Or, you can construct your own cheat sheet for selected lenses.
     
  5. Woo hoo! It gets even better. Thanks very much.

    Update Great for PC owners. :frown:

    Rich
     
  6. Bill N

    Bill N Guest

    You might want to also check http://www.tangentsoft.net for a small program called f/calc. It has dof, hyper focal distance, field of view, angle of view, magnification and f stops. It is freeware, nice little program. Good luck, Bill
     
  7. Thanks, very nice site!

    Rich
     
  8. I once saw a t-shirt with a hyperfocal distance chart on it......upside down, so that as you looked down at your t-shirt, you could read it. :biggrin:

    I'm *sure* you could find something like that for DOF too!!!! :biggrin:
     
  9. Flew made his own (I think) in Excel, and if I can dig it up it has graphs and other cool things...so if you are still looking for one shoot me a PM, and I'm sure I can find it somewhere.
     
  10. Rich,

    I use the aforementioned DOF Master installed on my Treo PDA. It works very well.
     
  11. Last edited by a moderator: Mar 15, 2017
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