|Posted by caseycrockerphoto on April 22, 2010 at 6:04 PM|
(written for Camren Photographic's March 2009 Newsletter)
The topic of shooting in photographic RAW format has come up in recent conversations many times at Camren. The question tends to come about when we help people select from the type of image quality and formats a camera offers. This goes beyond resolution and image compression. So, this newsletter offers its readers an insight into shooting RAW.
First and foremost, RAW is not an easy image format choice to tackle; It takes time and finesse. Choosing Jpeg image quality is quicker for one major reason; you allow the camera to process the image. Keyword process. A raw image is considered un-processed. When a photograph is taken, light reacts with the image sensor. We call these CCD or CMOS sensors. This is what makes a digital camera a digital camera. Where the film would be is now this sensor. Once this sensor receives light, it sends it through a processor, or an in-camera mini-computer. This processor makes certain adjustments to the image, things like auto-contrast and saturation boosts. Color-balance and image sharpness are also tweaked by this mini-computer. The image is then put to the compact flash or other media card as a Jpeg image. When RAW format is chosen, this image processor is by-passed and the photo is placed onto the card without these adjustments. It also technically isn't an image. At least not yet.
What you have to do is to pull the RAW file into conversion software. This typically is a program that carries with it an extra expense. Software such as Photoshop CS 3 (or the new CS 4 and Lightroom 2.0) contain a built in RAW conversion software. In this case it's called Adobe Camera Raw. Other companies offer conversion software, such as Nikon and their Capture NX2. Canon typically includes this software inside the box of the camera upon purchase. These softwares require you to make adjustments to the photographic image before it can be opened in editing software. Consider these adjustments as decisions.
After these adjustments are made, you then have the option of saving the image into whichever format you wish, such as a Jpeg. The main reason for doing this is that you inhibit the camera from making average adjustments to the photo before its turned into a Jpeg. Finesse. The end result will be more to your personal liking because you customize the image...something the on-board mini-computer cannot acheive. It's a large step. You simply can't just email a RAW file or post it to the web. You will have to adjust the following things in the raw software: White Balance, i.e. color temperature of the shot. This is a more accurate way of correcting color balance. Exposure, i.e. the contrast of the image. Much like adjusting the levels of an image. Image sharpness, or the appearance to the pixels, i.e. soft and smooth or sharp and full of contrast. Color Vibrance, which is different than color saturation in that vibrance represents more of a separation of colors rather than a boosting of color intensity. Of great imporatance is the ability to boost the information in just the shadow areas and/or inhibit highlight area blow-out with a tool called recovery (much like dodging or burning in the darkroom).
All of these adjustments are made before the image is compressed into a jpeg, which makes this process minimally-destructive to the image. Compression causes image information loss, so reducing this information loss is a good thing. You'll find your gradations of color and tones are more pleasing because they are more accurate. Think of it this way, if you shoot 100 ISO on your digital camera, by the time the mini-computer is done with the image, then you make adjustments without raw software, the final image is going to represent something more like an 800 ISO image. So, in fine-tuning these changes, you'll keep more color fidelity, tonality, and resolution and reduce the appearance of noise considerably. Plus, you'll have a sense of accomplishment.
Shooting well through the camera without the need for image correction is ideal. This mastering reduces your processing time. Newspaper photographers can get the image out quicker when shooting a well-shot Jpeg. Photoshop isn't the end all be all fix, but understanding RAW can help get you where you may desire to be photographically. And an ideal circumstance is learning from mistakes. If you learn from your pattern of mistakes based on the corrections you have to make in the RAW software, you will improve your overall image taking skill and hone your inherent talent.