Friday, September 04, 2009

Focusing

Out of focus photographs should be carefully watched for. With today’s cameras focus often feels like a resolved issue. On view cameras this was an enormous issue requiring a high quality magnifying devise to accomplish the task. Autofocus on digital cameras has made this issue less significant, but not fully resolved. I have two Nikon digital cameras – an s52 and a D80. The D80 is clearly the better of the two cameras in terms of image quality, but with it the focus as at best pretty good. With the s52 the autofocus works great. I loose many more photographs than I care to loose from focusing issues on the D80, although this can always be corrected with a second shot if I have a chance to check the first shot on the camera monitor.

Focusing is changing the distance of the lens from the sensor to make the photograph appear sharp. Focusing becomes increasingly more difficult to manage with low light and/or longer lenses. For most photographs focus is important. Although since around 1990 there have been many photographs publicly displayed that were intentionally out of focus and were stronger photographs as a result of this technique. If a sharply focused photograph is the intended objective, this must be watched carefully.

A preliminary focus check can be made with the camera by using the control that magnifies the image on the camera monitor. On the s52 I check at maximum magnification. This is pretty accurate. On the D80 there are 8 levels of magnification. If it appears accurate at the 6th level, it is usually in focus. The most accurate way to check focus is after transferring the files to the computer view them on the computer monitor at 100% magnification in Photoshop or other image editing programs. If they are out of focus, there is no way to correct this with image editing software.

© 2009 Paul Light all rights reserved

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