Okay, first, I’m not going to write a lot of technical stuff about it when there is Wikipedia. If you want to know more than the average bear about the science of depth of field, read the linked article. It brought back some photo class flashbacks for me. Too long ago, I left studying Aeronautical Engineering for Fine Art to get away from formulas… But there is good info in the top pieces of the webpage:
Wait. Writing about it is what this is here for. Depth of Field (heretofore referenced as “DoF”…) is a basic photography fundamental, right?
Right. Well, Sort of. This section/site is not about being a “pro.” I’m assuming here that whatever it is, a DSLR, iPhone or a point and shoot camera is capable and in capable hands. If you use the auto programs, most of them will give you shallow DoF in macro mode, and deep in landscape mode – so the basic result I want to get at with this post is an understanding.
The picture at the top is a snap I took the other morning before the sun came up. The DoF is extremely shallow, too shallow, actually, as I wanted the bottom leaf in focus as well… but it was a quick snap, and I didn’t bracket, so I’m generally happy with it. It’s a nice example, of shallow DoF. It was taken with my favorite lens – the venerable Nikkor 50mm f1.8 – that collection of glass has become even more fun with the ~1.5x focal length factor on the DSLR versus my film camera… (Digital focus factors and 35mm lenses on DSLRs might be something I’ll discuss at some point. Note to self…)
So, depth of field is something a casual shooter should understand and be aware of. Read the wiki article until it becomes too scientific. Then look to play with DoF – if you use a DSLR, you have full control via your aperture priority mode or full manual mode if you choose to use it. With point and shoot, often your program seetings can manipulate the DoF enough to really make a difference – try shooting something about five to ten feet in front of you in portrait and landcape modes if your P&S has them… see if you can tell a difference… Go shoot!