Depth of Field in Digital Photography

In my morning troll through the Pentax forums at DPReview (still lusting, wanting, and learning all I can about my object of desire without actually buying one (yet)), I found some interesting articles on Depth of Field, and in particular, how it relates to digital cameras.



Basically if you’ve ever wondered why your digital camera seems to put everything in focus, not allowing you to get nifty effects like the ones below (taken on my 35mm Pentax), even with the apateur wide open, the above might help to explain. It’s got math too, if you happen to like that πŸ™‚ Basically it’s got to do with the size of the surface capturing the image, as well as the lense, etc etc.







(Pentax P30T, 50mm F1.7 lense, F1.7 with unrecorded exposure, three closeup lenses on)


I think the quick and dirty answer is that if you have a nice D-SLR with a magnification factor of say, 1.5x (ie: a 50mm lense on a 35mm camera acts like a 75mm lense on your D-SLR), the depth of field is magnified the same way. Or something like that.

3 Comments on “Depth of Field in Digital Photography”

  1. Thats neat, i’ve been having trouble just figuring out how to do manual stuff like that with my digital camera… for a traditional SLR its so intuitive, I miss having a lens-barrel to hang on to…..

  2. Great articles, and nice example. πŸ˜‰
    That’s one thing that’s always been an annoyance for my Coolpix. Huge DoF is handy when you’re taking quick shots, or doing street work where you don’t necessarily have time to focus. But for situations where shallow DoF is required, digicams absolutely suck.
    At least I can get around it in post with lots of gaussian blur in photoshop. But that’s a pain. Damn, I wish Minolta would hurry up and release their DSLR….