Thursday, October 10, 2013

RAW files: What, Why, & When? ~

Whenever we've talked about digital files here -- setting the camera, printing them, emailing them, and so on -- we've been talking exclusively about JPEG (.jpg) files. And these JPEG's are great, they record a lot of visual information. Every digital camera out there shoots JPEGs, and every digital imaging program can open them.  So, end of discussion.

And yet, and yet.....

You keep hearing about photographers, and other visual professionals, professing their undying love for the RAW file instead. And I know some dental labs are starting to request their clients to provide them with RAW files, so it's probably a good idea to spend a couple minutes here and take a quick look at them.

All digital cameras have a menu setting, such as the Canon shown here, that allows you to select what kind of file you wish to produce. The one highlighted here is the large, minimally-compressed JPEG, which I always recommend when you shoot JPEGs. These files "see", or record, 256 discreet brightness levels (or shades), which is a good deal of visual information. If you work with histograms, either in your camera or in a graphics program such as Photoshop, you'll see they display all 256 of those levels.

In that same menu you also see a lot of other possible file selections: smaller, more highly compressed JPEGs, and several RAW file + JPEG combinations, which are useful if you want an untouched RAW file to send to the lab but want an easy JPEG to keep on your desktop or in your patient files. They take up more room on your card and take a bit longer to process. I usually only set the RAW file by itself, as I've indicated with a yellow arrow.

But what are you setting? Well, unlike the 256 brightness levels the JPEG gives us (which is described as "8-bit") the RAW file on most digital SLR cameras records in 14-bit, which is over 4000 brightness levels. This gives the photographer far more control over the image in post-processing.

And of course, therein lies the rub. More control also means more work, so work-flow considerations have to be factored in any decision to start using RAW files. Going through an extra step while processing a handful of images is one thing, but working on several hundred will be something else entirely. When you shoot a JPEG, you set the camera to do most of that work: setting the exposure, the white-balance, sharpness, tone curves, and so on.  But all of these things -- everything, in fact, except ISO and shutter speed & aperture -- can be manipulated after the shot is taken, using the appropriate software. This picture shows the RAW converter you would use in Photoshop CS6 and Adobe Photoshop Elements. This means, of course, that unlike the JPEG, the RAW file cannot be opened universally; it absolutely requires software capable of doing so. (After the file is opened and worked on, it can then be saved as a JPEG.) Therefore, while some dental labs are starting to look closely at using RAW files, due to the advantage of having so much post-processing control over the image (and thus color quality), many labs can't afford that additional workflow. So don't start sending them RAWs unless they specifically request it!

Those of you who have been in one of my workshops or seminars know how much I love photography and want to share that enjoyment. Here's a great way to experience it at a whole new level. Download a copy of Photoshop Elements 12 (you can get it on Amazon for around $89), take your camera out of the office for a weekend, and play around with RAW files. Shoot whatever you like and let Elements open them in the RAW converter, then see where it can take you.

Nothing wrong with a good, creative hobby! Although the next step would be leafing through photo catalogs looking at all those nice $2000 lenses....

Share your thoughts -- and your photos!

Later, Amigos.