Exposure Compensation

[geordie graham]

I am still very new to photography and after getting to grips with general bird photography I am now trying to get to grips with E V compensation.I have a Pentax K10D which has a digital preview which can show the histogram of the shot once it is focused etc.Am I right in thinking that by checking the histogram and dialing in +/- compensation depending on the position of the peaks and getting the peaks more or less central,then I should have the exposure more or less correct.Also is it best to use 1/2 or 1/3 increments.I have noticed some people have +/- compensation permanently dialled in,does anybody do this with their K10D.Thanks

Graham

[GerryNick2]

Hi Graham

Your assumptions are in the main correct. The left side of the histogram indicates dark pixels captured and the right side bright pixels. If there are peaks touching the left side this indicates underexposure and peaks touching the right side indicates overexposure. If the histogram indicates peaks mainly towards the middle then this indicates a balanced exposure.

If the image is underexposed dial in a +/ compensation factor,this has the same effect as selecting a slower shutter speed or larger aperture in manual mode, letting more light to the sensor. If overexposed select a /- compensation factor which if in manual mode is the same as selecting a faster shutter speed or smaller aperture letting less light get to the sensor.

My personal preference is to use 1/3 increments and leave /-1/3 selected for most of the time. This seems to give me the best results for my particular camera and something you will need to experiment with.

Nothing beats a perfect exposure but with the introduction of more sophisticated software there is a line of thought that it is best to underexpose and recover the lost detail in the shadows in post processing. Overexposure should be avoided as this results in what is termed as blown highlights, a loss of detail in the highlights which cannot always be recovered by software as the information is just not there to recover.

When shooting fungi for example in poor lighting I keep taking shots and adjust the exposure each time by -1/3 until I get a balanced exposure.

There are however exceptions to the rule so my advice is to keep practising, a good digital photography book will cover the subject in some depth. There are also some very good articles on the web.

The thing to remember is there is no good or bad histograms. A histogram just tells how the picture is exposed and the photographer retains the control to decide whether and how to adjust the exposure. You might decide to compensate for the under or overexposure, or you might even want to select an underexposure if that is the effect you are after.



Gerry

[Hobjob]

Originally Posted by GerryNick2

Nothing beats a perfect exposure but with the introduction of more sophisticated software there is a line of thought that it is best to underexpose and recover the lost detail in the shadows in post processing.

Absolutely true - but there was thread (+link) a while back about using very high ISOs, which said to do the opposite to reduce the noise; well worth a read.

[geordie graham]

Thanks to everyone good advice.Will just carry on enjoying and learning.thanks again.

Graham