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Mocavo

Some people eat, sleep and chew gum, I do genealogy and write...

Sunday, May 23, 2010

File formats for saving "original" photos -- Part One

A recent Blog post by Dick Eastman, "Never Save Original Photos in JPEG Format!" got me thinking again about the format for storing digital images. One of the first issues that came to mind was the limitations imposed by the camera you select. Many of the consumer level cameras do not give you an option for the file format of the images produced. Over my lifetime I have steadily evolved the cameras I use. My original camera was a cheap, off the shelf fixed lens 35mm view finder camera, which, by the way, took horrible pictures. My first real efforts to improve my photography began with a Canon 35mm range finder camera. That was a beautiful camera with an extraordinary lens.

When I served in the military in Panama, I took advantage of Japanese import prices to acquire a complete Pentax camera system. Of course, all of these early cameras produced slides and prints. I stuck with Pentax for the next level of photography, when the electronics began to improve the quality of the images and the ability of the cameras. I immediately saw the advantage of digital cameras, but like most photographers were not impressed with the quality of the images. Digital storage was expensive and computers were slow and clunky. Processing any image of adequate quality was a slow and painful process.

My first serious venture into the digital camera world was with a Panasonic Lumix. I am still impressed with the quality of the lenses and the camera itself. But time moves on. The next camera was 6.2 Megapixel, HP Photosmart R717. That camera took extremely good landscape pictures but did a poor job of closeups. It was not a camera for a photographer because of the lack of versatility. Although the camera is still for sale, many of the newer cameras have more and better features and better lenses. I now do not think it is a good idea to buy a camera from a computer company. Buy a camera from a camera company.

The next step, was to go back to my roots in Canon cameras and I purchased a Canon EOS Rebel Xti which has been replaced by the Canon EOS Rebel T1i 15.1 MP CMOS Digital SLR Camera with 3-Inch LCD and EF-S 18-55mm f/3.5-5.6 IS Lens for the same price (or less) than I paid. With that purchase I began to enter the real world of digital cameras. The next step came about as I began to realize the limitations of the Xti. The next level was the Canon EOS 50D 15.1MP Digital SLR Camera with EF 28-135mm f/3.5-5.6 IS USM Standard Zoom Lens.

Ok, now what were the real issues? I was learning more and more about digital imaging and realized that the manufacturers of the cameras had finally allowed direct access to the data from the camera. Creating, what was in effect, a digital negative. From Wikipedia, here is the explanation of the Raw image format:
A camera raw image file contains minimally processed data from the image sensor of either a digital camera, image, or motion picture film scanner. Raw files are so named because they are not yet processed and therefore are not ready to be printed or edited with a bitmap graphics editor. Normally, the image is processed by a raw converter in a wide-gamut internal colorspace where precise adjustments can be made before conversion to a "positive" file format such as TIFF or JPEG for storage, printing, or further manipulation, which often encodes the image in a device-dependent colorspace. These images are often described as "RAW image files" based on the erroneous belief that they represent a single file format. In fact there are dozens if not hundreds of raw image formats in use by different models of digital equipment (like cameras or film scanners).[1]
Raw image files are sometimes called digital negatives, as they fulfill the same role as negatives in film photography: that is, the negative is not directly usable as an image, but has all of the information needed to create an image. Likewise, the process of converting a raw image file into a viewable format is sometimes called developing a raw image, by analogy with the film development process used to convert photographic film into viewable prints. The selection of the final choice of image rendering is part of the process of white balancing and color grading.
Here was the key to getting high quality images from a digital camera. Use the camera's RAW settings. This ability of the cameras adds a great deal of flexibility and huge level of complication. Now, back to the comment about never using JPEG. Unfortunately, most of the consumer level cameras, especially those made by computer companies, do not allow the export of RAW data from the camera. More and more cameras are supporting that format, but even though the camera may allow you take a picture, store it in RAW format and then download the RAW image to your computer, that does not mean that you can use the photo at all in that format. To adequately use RAW format, you have to be willing to "develop" the pictures using some processing software, such as Adobe Photoshop CS5.

It only gets more complicated from there. Adobe Photoshop is likely one of the most complicated programs currently sold to consumers who are not professional programmers or computer experts.

What is the advantage of RAW format? Well, first of all it avoids all of the limitations of the JPEG and other lossy

Stay tuned for the next installment.

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