Some folks live and die by the sharpness of an image. I am not one of them. I am totally fine with an image being downright soft as long as it’s sharp where it needs to be. But for those who want to maximize sharpness, here are some tips. NOTE: This list isn’t comprehensive, but should be sufficient to get you started.
1. Shoot in great light. If you’re relying on autofocus, it works best in good light. If the light is poor, the AF tends to work poorly.
2. Find the sweet spot for each lens. Most beginners make the mistake of thinking that by stopping down to the smallest possible aperture, they are increasing sharpness. They are actually increasing depth-of-field. If you want the sharpest possible aperture, it’s usually somewhere in the middle of the range. Test your lenses by photographing newsprint on a flat surface in consistent, good light. This will help you find out which aperture gives you the best performance.
3. Use a steady tripod. Locking your camera down on a good, heavy tripod will help you get sharp pictures. Use a solid head, a solid tripod and a good sturdy mount. Lock down all the legs and the head for maximum sharpness.
4. Use a fast shutter speed. Faster shutter speeds reduce the effect of camera shake or movement.
5. Use the correct autofocus mode. If you’re shooting moving subjects, make sure you use your camera’s AF tracking mode. If you’re shooting static subjects, simple one-shot mode is best.
6. Avoid subject movement. If you have to work in low light with low ISO and low shutter speed, subject movement can cause you to make out-of-focus or blurry images. Make sure to ask your subject to stand as perfectly still as possible in these conditions.
7. Pick the right ISO. Use an ISO that will allow for a fast shutter speed without introducing too much noise.
8. Avoid problems related to filters. Cheap filters can reduce sharpness in your photographs. Stacked filters can cause lens flare (both the obvious kind and the less obvious kind that reduces contrast and thus apparent sharpness.)
9. Avoid using too much noise-reduction software. Too much or improperly applied noise-reduction will reduce your image sharpness.
10. Use the right amount of post-processing sharpening. Many beginning digital photographers are unaware that you need to use more post-processing sharpening for printed images than you do for images displayed on the web. If you’re printing on photo paper, adjust the image on your computer monitor so it seems just a bit too sharp on the screen. This is usually the right amount of sharpening for a print.