If you look through the menu or manual of your digital camera, you will certainly come across the point exposure correction or compensation. What is it and do we need it?
If you come from the old school of analogue photography, you may have learned the following:
Slide or reversal film – in doubt underexpose
Negative film – in doubt overexpose.
The reason behind this was, that slide films, once exposed and developed could not be corrected and an overexposed part of the image, or a very bright part at least, would be disturbing. Even through copying with corrections the overexposed areas could not be recovered, while a ‘to dark’ colour negative could always be pushed during the production of enlargements to get more detail into the darker or underexposed parts of the image. Apart from that, film had a much wider exposure latitude compared to digital and thus could tolerate more extreme lighting.
In Digital all this has changed a bit, since our sensors have a narrower exposure range or latitude and tend to wash out bright lights very easily. Like slide film, once the details the exposure are gone, they are gone and you are left with a white blob.
To overcome this, technologies, such as HDR have been developed and I often use them if I take pictures with my smartphone. But if you have a digital camera, regardless which type, better understand and work with the exposure compensation.
In general I keep my cameras at -1/3rd or a third lower exposure then ‘normal’. This darkens the image ever so slightly and deals better with bright lights.
If I have very extreme light, and I do not want to change my metering type (Matrix, centre weighted or spot), I may even go to -1 or more. You can observe the result on the viewfinder or rear camera display. Some camera make it easy, like the Leica CL I tend to use a lot. Don’t worry if you think that parts of the image will be to dark. Even the most simple image correction program, as Preview in Mac or Picture in Windows lets you make the dark (shadow) areas brighter without washing out the the bright parts of the image.
If you look at this picture, taken from a moving car, you can see very bright light and very dark shadows. The camera a Leica T was set at minus 1/3. But the right side of the histogram below was still very high up. So I took the digital negative file and lowered the brightness of the lights (you can see the line on the right) a bit and now you can see that there still details within some of the very bright parts. But equally there are details in the shadow areas. If I had kept the camera at ‘neutral’, I may not have been able to save the bright lights.
A similar problem with this image. Dark shadows at the trees, neutral bright sky and white flowers. Of course you still want to see the yellow and blue details in the flowers as well. An added complication was, that this picture was taken with a Nikon 10mm fisheye lens, which really covers a very wide area. Again the camera was set at minus 1/3red of an aperture. This shot was taken with spot metering.
In summary. I recommend to keep you exposure compensation always at -1/3 or -1/2. Not only will you have more balanced results, but also deeper, more saturated colours or if you are into B&W photography, set it at -1 and you get deep blacks and detailed whites.