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June 02, 2006
Imaging Problems – Part Two
Noise is the most troublesome imaging problem but it is not the only one. Other problems related to colour, contrast, detail and sharpness may also be experienced.
Most cameras can be set to automatically adjust the white balance. This setting is usually the most appropriate but for tricky light situations the automatic setting may be turned off to allow the photographer to manually adjust the camera. This can also be used for artistic effect -- a white balance set to an extreme can produce weird, unearthly colors.
Most of the time, however, accurate color reproduction is desired. Inaccurate colors can be compensated for with imaging software, but it is always good practice to capture the best colors at source.
Improper exposure times can also be corrected with software, but again, it is better to try to capture the best image possible. If you have the opportunity to re-shoot a scene which has been improperly exposed, by all means go ahead and try to improve the image. However, if the scene cannot be re-created, save the image and try to work on it with software.
Of all the imaging problems, those caused by poor quality lenses can be the most difficult to correct. Quite simply, a bad lens is going to give you bad images. That is why it is essential to choose a digital camera with the best quality lens you can afford.
However, even good quality lenses can produce distortion at their extreme focal lengths. This is usually easier to correct as the distortion will most likely be in terms of inaccurate horizontals and verticals. Imaging software can be used to compensate for minor variations in straight lines, and the slight irregularity in these situations are sometimes not at all unpleasing.
It is almost impossible, though, to clear up a blurry image caused by a cheap plastic lens. If image quality is important to you, be sure to get good-quality glass lenses and keep them well maintained. Dirt and dust on lenses can cause distortion and noise in the final image, so keep them as clean as possible without excessive handling. A soft brush and a blower should be all that is needed if the lenses are kept covered when not in use.
Most of the imaging problems discussed above can be fixed using software. Professional imaging software such as Photoshop can be used to correct color irregularities, white balance, lens distortion, incorrect exposure, and blurring. Although Photoshop has a steep learning curve, many of the same functions are available in other software packages which are easier to use and less expensive.
Digital photographs, after all, are computer data which can be manipulated down to the bit level, so it is always possible to change the minutest detail of any image. Software can automate many of these corrective functions, and manual manipulation is also possible to improve any digital image.
Posted by DigitalCamera at June 2, 2006 01:00 PM


