This discussion has been going on since the formats were made available years ago. Most inexpensive digital cameras only have jpeg/jpg format available. This ability is usually graduated in Fine, Medium and Small size meaning the Fine setting has more pixels and consequent quality than the Small setting which has lesser pixels in the image and consequently more images per memory card.

The better quality cameras have in addition to the jpeg format Raw capability. Raw has more digital picture information per image file. Therefore, it has better quality in terms of pixel density, color information and consequent reproduction/enlargement ability. This format is favorite of most professional photographers mainly due to the White Balance control availability. White balance is a light color setting not directly available in photo editing software. It provides for a color range from cool to warm and can change the mood and tone of an image dramatically.

Shooting jpeg lacks this adjustment therefore, if an image is shot under daylight conditions which has an average Kelvin reading of 5200, the image can not be made cooler or warmer other then changing the color cast greener/bluer or reddish/yellowish manually. This type of cooler/warmer picture change is not the simplest nor does it provide for the wanted results. So, raw has this ability and most photographers like to have it available even they do not need or use it. Another raw format plus is that the image file is not compressed (lossless) providing for multiple file handling without loosing pixels and consequent image quality.

Jpeg however, is a compressed format from the get go. A high quality raw image file of a certain camera can be  2.2 Mb whereas the same image with a high quality jpeg setting is only 5 Mb. This means that the camera image engine information was compressed from 2.2 Mb to 5 Mb loosing digital image information in the compression process. If image information has been changed from 2.2 Mb pixels to 5 Mb pixels something has been done away with and that something is part of the color gamut and consequent image quality.

The prevailing attitude toward this is surprising and probably bases on ignorance as the following suggested practice bears out;

A discussion with a well know photographer from the West Coast had the following to say on the subject, "I shoot JPEG because I can not see any quality difference between JPEG and other formats. I like the increased shooting capability when out in the field." When asked about the often discussed problem of image degeneration during image file handling he replied, "I convert my JPEG images immediately after uploading into Tiff format." thereby indicating that the image was not subject to further degeneration because of the Tiff conversion.

No further image quality degeneration after Jpeg into Tiff conversion I can agree with, but he seems to miss the point here that the Jpeg image was already degenerated by the camera software where it was converted and compressed by "in camera digital format conversion software." Converting the image into Tiff is a prevention for further image degeneration when he image is being handled over and over again but the conversion and consequent compression from Jpeg to Tiff can not restore what the camera software did away with. What happened to the 1.7 give and take Mb pixels that were deemed redundant during that compression? That question can not be answered precisely because the pixel elimination process depends on software algorithms used. One thing is for sure, no conversion process can create what was not there!

At the end of the day it comes down to this; If you are happy with Jpeg quality then that is the way for you to go. Saving the image into Tiff format will prevent further deterioration but will increase your storage needs. As a final word I would like to say this; a day on the beach is certainly not worth shooting Raw and I would shoot Jpeg and, probably archive in Jpeg or a lossless Jpeg format. A shoot however in the Botanical Gardens is certainly worth the extra processing to shoot the Raw format!

postscript7/2009

Recent developments in the HDR (high definition range) photography software converters with abilities to generate a pseudo HDR image from a single RAW picture has put another importance on the RAW format. The ability in detailed in our HDR Photography article of June 2009. This article is also available on the Atlanta Photographic Society web site.