IMPERFECT HISTOGRAMS?

Tuesday, September 06, 2005

While browsing through some digital photography forums, a link lead me to a discussion on photo.net which debates the correctness of the histogram displayed on the camera lcd. Being linear, histogram of a raw image would not be useful in understanding exposure. Hence the histogram displayed in the camera would not correspond to raw image, but of a converted jpeg image within the camera. This means that your histogram really depends on the raw conversion software you use and not just the exposure you have used. Besides, the parameters set on the camera can affect the hostograms and complicate the issue much more. What is shown as blown up area in your camera could well be recovered by using a different conversion software. So while we can still use the histogram as a reference for exposure to some extent, all may not be lost if you have blown up some portions of your picture. Your histogram may be lying to you! Read the threads that discusses the issue -

- http://photo.net/bboard/q-and-a-fetch-msg?msg_id=00DBgo
- http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00D5Kj