THREE REASONS WHY YOUR PHOTOS MIGHT NOT BE SHARP
From time to time I run into someone who is disappointed in their new lens (usually some kind of telephoto) because ‘it just isn’t sharp.’ Yet when I put it to the test, I have no problem getting a sharp image. Don’t get me wrong…sometimes you can be unlucky and get a dodgy lens. But more often than not, it’s a failure in basic camera technique, and not the lens, that is at the heart of the problem. So here are three reasons why you might have trouble getting sharp photos.
SHUTTER SPEED IS TOO SLOW. A moving subject, or even a moving camera, can cause motion blur in your photos. At the very least, you need to have a fast enough shutter speed to eliminate motion blur caused by camera-shake. That can vary depending on the size of the lens. The larger your lens, the faster the shutter speed needs to be, and you can use the focal length as a guide (i.e. 200mm lens, shoot at a 200th of a second or faster, 300mm lens, 300th of a second etc.). But when shooting a moving subject, you probably need to go even faster. To freeze most kinds of action you usually need a shutter speed faster than 1000th/sec.
AUTOFOCUS IS MISSING THE TARGET. When someone shows me a photo that is ‘not sharp’ I can usually show then that it is sharp…just not sharp in the places they wanted it to be. If you are shooting a bird through the branches of a tree, the camera might focus on the branches and not the bird. Have you looked at your autofocus options? You should be able to refine your AUTOFOCUS AREA MODE to a single-point option (it may be called spot focus, single point, single area, one-area etc. depending on the camera). One way or another you need to be sure the camera is focusing exactly where you want it to.
THE PHOTO IS SHARP, BUT THE DEPTH OF FIELD IS SHALLOW. The closer you get to the subject, the shallower the depth of field becomes. The larger the lens, the shallower the depth of field becomes. So if you are close to the subject using a telephoto lens, you can expect the depth of field to be very shallow indeed. This is particularly true for macro photography where the camera is VERY close to the subject. So it’s quite possible your photo is very sharp, but only on a very small part of the image. In this case, you have some options to increase the depth of field. You can use a tripod and slow the shutter speed down, which will allow you to use a smaller aperture. Or you can simply move the camera a bit further away from the subject.
In any case, no matter what settings you use you are going to find yourself in situations where the depth of field is shallow no matter what. So that makes my second point (above) even more important. If only one part of your photo is going to be sharp, you need to be certain the camera is focusing EXACTLY where you want it to.
If any of these tips don’t make sense to you – or even if they do make sense but you don’t know how to make it happen on your camera – this is exactly the sort of thing I teach at my workshops. Contact me if you want to learn more, either at a Photography Essentials Workshop or a day of One-On-One Tuition.