Thursday, July 16, 2009.
I apologize for the late post today, I wasn’t able to get to it earlier. And, you’ll notice that I went with another flower today. Yes, that means I don’t really have the time to do a nice fancy writeup today either. But, hey, it’s a pretty flower! And it’s ORANGE! That’s, like, one of my favorite colors! It’s in the top 10 at the very least.
Actually, I just thought of something interesting I can say about it!
So, when you’re taking pictures of things that are really close, such as flowers (macro photography, if you will), you are generally dealing with an *extremely* small depth of field. Part of that is due to the aperture you’re using, but a bigger part of it is the much smaller relative distance of the subject. If you look at a camera lens that has markings on it for focus distance (there’s a fancy term for it, but I’m drawing a blank), you’ll notice that the ratio between how much you crank the focus and the distance to the focus point isn’t constant. Not even close. The first half of the focus gets you from a few feet away to maybe 20 or 30 feet away. (Just tossing these numbers out there without having a camera nearby, so the actual numbers are probably way off, I’m just trying to illustrate a point here.) But the rest of the focus moves it out to 50 feet, 100 feet, 200 feet, out to infinity. The difference between focusing on something that is 300 feet away and something that is 10 miles away is very small. But the difference between focusing on something that is 50 feet away and something that is 5 feet away is HUGE. It all has to do with math and all that, but just remember that the closer something is, the more significant small changes in distance are.
Why am I talking about all of this? Oh, right, flowers. As I was saying, even if you’re using an aperture that should result in a fairly large depth of field, the literal distance that depth of field will cover is pretty small when you’re taking pictures of things that are very close. Small enough that, unless you’re taking a picture of it straight on, you’ll be forced to deal with the question of which part(s) of the flower you want to be in focus. (If the center is in focus, that’s a much different picture than if the front of the petals are in focus, for example.)
As you can see here, in this picture I decided to emphasize all the dangly bits in the middle. (I really wish I was more fluent in talking about flower parts…) I felt that being able to see the crumbly nature of the pollen was more important than being able to make out every last wave and curl of the petals. Is it? Who knows, but that’s the picture I got.
Anyway, all this talk has made me hungry. Fortunately, I found a cake with lilies on it. Perfect?
Notes: Canon EOS Rebel XT, Quantaray 70-300 mm lens. 1/640s, f/7.1, ISO 100. Focal length: 183mm.