Monday, 3 September 2012

What is Overexposure in Photography?

In the previous article we discussed What is a Good Exposure?. Overexposure happens when more light enters the camera than it is required to make a good exposure. This could happen due to a number of reasons.

Photo By Jason

  1. The shutter speed used for the shot was too long.
  2. The aperture set was too wide.
  3. Wrong selection of ISO

At times photographers mainly those in the fashion industry deliberately overexpose their shots for artistic effects and this technique quite often produces fascinating pictures. But on occasions where it was not intentional, overexposure often spells disaster. Although some amount of damage control is possible in post production by adjusting the mid tones, (especially if the file format used was RAW), there is no way to recover detail from a grossly overexposed image.

In the case of digital photography, overexposure results in a washed out image with subdued colours and not much contrast. There will be little or no detail present in the highlight areas and such areas where only pure white is recorded with no detail is called ‘blown out’; meaning it cannot be recovered by any means.

When photographing using negative films you could easily identify an overexposed shot by looking at the negative, it will appear very dark. But unlike in digital photography, overexposure is not such severe a problem when using negative film, as details will still be captured on an overexposed negative film and the issue could be rectified by using the correct choice of printing paper contrast and increased exposure time during enlarging. This however is not applicable for grossly overexposed shots.

It is interesting to note that in cases were negative film is used overexposure could even happen during post production. It is called over development it usually happens when;

  1. The film is left in developer for too long
  2. The developing medium is too strong
  3. The developer is too hot

And film manufacturers have actually provided a way to photographers to know whether the picture was over exposed or over developed. If you look carefully at the edge of the film negative, you will find markings there; if the markings appear dark and smudged then the image was overdeveloped and if the markings are clean then the image was overexposed.

When photographing using transparencies you will have to nail your exposure right and if in doubt bracket your shots as there is no way to do any sort of damage control later on.

In the next article we will discuss about Photography - Tips For Beginners - Underexposure

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