Friday, June 11, 2010

As sharp as it gets

So you finally bought your dreamed DSLR with a couple of pro lenses, but you are not quite satisfied with the results. For some reason images are not as much sharp as you expected them to be. What can you do? Well there are a couple of things:

1. First make sure that your lens copy in not defective (you can check out Some companies tend to produce bad copies of lenses. If you find out that you own a bad copy, ask your dealer for replacement.

2. The rule of thumb states that best sharpness is being achieved at 3 stops above the lens’ wider opening (eg. for a f2.8 lens, use f8). Note that this rule in not true for every single lens, it’s just a general rule. The best thing you can do is to know the sharpness distribution of the specific lens you own. You also have to have in mind that aperture affects depth of field, so use it accordingly (eg. when photographing a landscape you should consider using a smaller aperture than f8; f16 for instance may be more appropriate).

3. Use a study tripod when possible. High speeds and stabilizers are good things to have, but nothing can contribute to sharpness more than a good tripod. Things to know:
a. Aluminum tripods are good and can be bought at reasonable prices, but there are also heavy and prone to vibration. Carbon fiber tripods are a better choice but (at the current moment) they are more expensive than aluminum tripods.
b. When using a tripod remember to turn off the stabilization system. When turned on, these systems are seeking for vibration and in situations that vibration is not present they tend to produce one.
c. Trigger your camera remotely; don’t press the shutter release button, since even the slighter vibration caused, is a sharpness sacrifice. Use instead a remote cord or a remote control (depending what your camera supports). If you don’t have one, use your cameras’ self-timer function.
d. Use mirror lock up (MLU). When you are taking a picture, the mirror is moving away just before the shutter opens. This movement causes a small vibration inside the camera body which results in some loss of sharpness. When using MLU, you press the shutter release once to lift the mirror and you press the shutter release a second time to open the shutter and take the picture. In that way vibrations caused by the mirror are dissolved before the shutter opens.

4. Check your camera’s settings. Most cameras have in their menu some settings for controlling the sharpness and color of the final image. These are post production settings in a sense that they are applied during the conversion of the RAW file and embedded in the final JPEG. If you are shooting RAW the settings do not affect the actual file (they affect only the JPEG preview of the RAW file) so you can change them later on. If you are a JPEG shooter, these settings are embedded in the final JPEG (and you have to leave with them).

5. Adobe Camera Raw, Photoshop and other image programs allow you to alter the sharpness of your image in the comfort of your home. The amount of sharpness for each image and the way to apply it varies (and these are not part of this tutorial; maybe in a future one!). The important thing to have in mind is that post-processing sharpness is not “real” in a sense that it produces the illusion of sharpness by applying edge contrast.

So, turn off your computer, pick up your camera, lenses & tripod, get out there (yeah , it’s a really beautiful world!) and make some great sharp images!

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