Otherwise known as “pay a fortune for sharpness nobody is really going to see” lure that many, many, of us fall for…
Ask yourself what you’re going to do with your images before running off to buy the latest and greatest lens that’s so sharp it cuts the subject on sensor. Why? Because the way 99% of people are going to look at your photos matters. Who are you catering to? The guy with the loupe carefully examining your 8″ x 10″ glossies? Oh, wait, you don’t print those any more do you? Do you put them online? Most of us do. That matters.
I’ve been thinking about this a fair bit recently, since I’ve been looking around trying to figure out what lens I should be getting for my nature walks. I like taking pictures of small creatures such as birds, chipmunks, and the like as I’m walking through the woods. When I first got my Pentax K10D, I had a Sigma 70-300mm f4.5-5.6 lens and used it for some time. It’s a pretty inexpensive lens, one that “professional” photographers are sure to avoid, but it did just fine. Why? Because a 1200×800 pixel copy of that image displayed on the average computer screen looks plenty sharp.
Fast forward to today and I’m now shooting with the Nikon D800. When this camera, with it’s whopping 36 megapixel sensor, was announced, everybody insisted that you were going to need the best glass you could get in order to really take advantage of this camera’s ability. Consider that the base image dimensions are 7360 x 4912 and at 300 pixels per inch (usual for gallery prints) you would produce a print that was 24.5″ x 16.4″ in size. Do prints that big very often? I don’t, though I do have a few images that I’ve printed 36″ x 24″ using good tools to scale the image, but this is pretty rare. These days, I often publish shots at 2400 x 1600 on Flickr, which is a pretty decent sized image for a computer display. Heck, I have a 27″ iMac and that’s almost a full screen shot for it! It’s also 4 megapixels… Hmm.
So, where did I land? Well, I ended up buying the AF Zoom-Nikkor 70-300mm f/4-5.6G for all of $500 (after taxes). It’s light, it’s quite well built despite the plastic body, and it’s sharp when stopped down. Sharp as I need it to be, and probably as sharp as most of us need it to be.
Now, I’m sure that this is going to elicit sounds of horror amongst some as in “that lens on a D800?!? My word, is he insane!” Maybe… However, I’m sure that I’l end up with something else in the future, maybe, but in the meanwhile it does okay…
So, the thing about lenses is that most of them are very sharp in the center. Many lenses do, in fact, get soft in the corners, but are you looking at the corners? Do you place your subject there? Probably not. Do your viewers minutely examine the image looking for signs of blur? Probably not. Do you hold the image inches from your face? I don’t, even when I hang it on the wall. If you ever get a chance, take a close look at a billboard photo, you’d be surprised at the size of those dots!
Now, don’t get me wrong, there are people that probably do need very sharp lenses. I don’t know how many, but I suspect it’s not a lot. It probably depends on how you sell your images. There are, though, masterpieces of photography that have all kinds of softness in them. It’s not the sharpness that defines the value of the image, it’s the image. To quote Ansel Adams: “There’s nothing worse than a sharp image of a fuzzy concept.”