The tools or functions listed below may or may not be on your camera. Check your camera’s manual to see if they are available. If so, these tools can help you achieve better exposures even in default lighting situations.
RAW File Format
If available this is probably your first defense in better exposure but, it may require special software. Shoot in the RAW file format if possible. RAW files have all the information and will even have more detail in the shadows and highlights that are lost in the JPG file format. JPG files from your camera discards a lot of useful information that can help in post processing. This may save an otherwise bad exposure.
Use the histogram on your camera and try to keep the graph somewhere in between ether side of the histogram box. This will give you the best exposure possible. If the graph goes beyond the right or left it will be over or under exposed. This is called clipping. Just note that if you have really bright or dark spots in your photograph you may not be able to remove all the clipping.
Examples below of histograms with under exposed, properly exposed and over exposed photo
This is an example of an under exposed photo. Notice the graph is running past the left side of the histogram. This is clipping on the left. Remember all the information that is past the left or clipped is lost and will show up as pure black on your photo.
This is an example of a properly exposed photo. Notice the graph is centered and to the left side of the histogram. There is a small amount of clipping on the right. This is normal because there are some bright white spots in the photo.
This is an example of an over exposed photo. Notice the graph is running past the right side of the histogram. This is clipping on the right. Remember all the information that is past the right or clipped is lost and will show up as pure white on your photo.
Please note I have used Lightroom histograms in these examples. The histogram on your camera may look different but will basically work the same.
Highlights or Blinkies
Highlight point display or the “blinkies”. This is a mode where the display on the back of the camera will blink in bright spots on the display or photo. This works similar to the histogram. as the blinking shows the clipping only on the overexposed portion of the display or photo. This can be an easy way to check exposure. Just a note - some blinking may be ok in areas of your photo such as clouds, the sun or very bright spots.
Consider using the exposure compensation function in Aperture-Priority or Shutter-Priority. Use this function if your histogram is clipping. In manual mode this can be done by adjusting the aperture or shutter so that you compensate by over or under exposing as needed to get the histogram to not clip as much as possible. This is really handy in default lighting situations like bright sunny days or in winter with snow and sun.
One more option to consider is the exposure bracketing function. In this function you will take 2 or 3 frames or more (I set mine to 3 frames and +/- 5EV in increments 1/2) . 1 would be properly exposed, 1 over exposed and 1 under exposed. Then in your photo editing program pick the one with the best exposure.
Exposure bracketing can also be used in HDR or High Dynamic-Range photography and the program I use, Photomatix Pro 3.1, It is a standalone program and also has plug-ins for Adobe Photoshop CS5 and Adobe Photoshop Lightroom 4. In HDR you shot multiple photos all at different exposures. Then using a program in post processing to combining them into one photograph that uses the best exposed portion of each photo shot. Real Cool! I will cover this more in detail in a future article.
The post processing software available today can do a lot to repair a badly exposed photo, but it cannot repair or bring back information that is lost by clipping.
This is the software I use in the order that I use them the most.