RAW Images
If you have a DSLR, you have probably noticed a file type called RAW. They have file extensions like CR2 (Canon) or NEF (Nikon) appended to their names. I would like to go over the benefits of using RAW files and how you use them in capturing the best image quality from your DSLR camera.

Definition of RAW

RAW image files are sometimes called digital negatives, since these files are not directly useable as an image, but has all of the information needed to create an image. RAW files like a film negative have a wider dynamic range than the final image format i.e. JPEG. JPEG because of compression and the fact that all of your camera adjustments, such as AWB and saturation are done results in some of the file quality is lost. RAW image formats are intended to reproduce as closely as possible the physical information about the light intensity and color of the scene.

Benefits of RAW

• Higher image quality because all corrections are applied at once.
• RAW is an lossless type of file whereas JPEG throws away a percentage of the file information to make it smaller this results in JPEG's having less colors.
• RAW conversion software allows you to have finer control of any corrections you apply. An example is that white balance is infinitely adjustable, whereas on the camera daylight is a fixed value. Corrections to RAW are previewed on the computer.
• Large changes in exposure, resulting in dramatically less visible flaws such as posterization with RAW files.
Drawbacks of RAW

• Camera RAW files are 2 to 6 times larger that JPEG files, so fewer files can be put on a memory card. This size difference also slows down the camera write speeds to the memory card.
• RAW files require specialized software to process the image after it is downloaded to your computer, so the file can be used to print images or transfer. Canon and Nikon make a converter for their RAW files and
Adobe has Photoshop and Elements for conversion. Apple computers also have a built in converter for RAW to other formats.

Working with RAW files

If you have a Canon DSLR, Canon gives you a nice RAW converter for their files. Just install the software on your computer and change away. This software saves in TIFF format for use in Photoshop or Elements. With Nikon cameras in order to convert RAW files you need to purchase their Capture NX 2 software. They only provide this converter for free with their pro cameras. If you don't want to pay for a converter program and you are using an Adobe image program use this link to download DNG:
ADOBE This software reads lots of different RAW files and converts them to a universal RAW file for use in their software.

The workflow I use when I shoot RAW files is as follows. I download all RAW files from my memory cards to my computer. I store the files in the Pictures folder in a folder titled with the name of the event, ie. Yellowstone 2010 or Joe's Birthday 2010. In this folder I Make A RAW folder to hold those files. Once these files are downloaded, I burn all of the RAW files to a DVD for backup. I have had hard drives fail so I am very careful with my image files.

Once the images are safely saved, I open Adobe Bridge to start the process of converting from RAW to TIFF. Bridge allows me to look at all the files in a folder and then open the ones I want to correct and save as TIFFs. When you double click one of the RAW files, Photoshop opens the RAW converter module where you make your corrections. Bridge allows you to see the images in a larger preview, so you can decide if you want to convert them. Since the RAW images aren’t changed I can always go back and reconvert them. Just a note; Adobe’s RAW converter does make changes to the original, but they are non destructive changes.


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