A Raw Primer

Foam #5. Eldorado Canyon, Colorado, 2012

Since I have read and participated in a couple of different online discussions lately about the nature of raw images in digital photography, I thought I might try and post a quick summary of the topic. There seems to be some confusion, even among more experienced photographers, so maybe this brief explanation will help.

An Overview

Some folks consider the raw image produced by your camera to be the “negative” as it needs further “developing” in the post-processing phase to become a viable, usable, printable image. The raw file contains the maximum amount of image information your camera and sensor can capture. It is minimally processed, meaning that very little at all is done to it in-camera except, perhaps, for eliminating defective pixels. That is why a raw file will look quite flat and boring when you open it. Now, the raw file does also typically create an imbedded JPEG which is what is used to generate the preview image and histogram on your LCD. This JPEG preview–and this is important–is affected by the basic picture controls you set in the camera’s menu… things like white balance, saturation, contrast, vibrance, sharpness, noise reduction, etc.

So, with your camera set to record RAW images, you get that raw file for later download, but what you see on the LCD and the histogram is a JPEG based on your camera settings. That is why some raw initiates complain: “My image looked pretty good on the LCD, but when I opened my raw file it looked terrible!” Well, the raw file was never meant to be used without post-processing while, in the case of a JPEG file, the post-processing is done in-camera.

Also–by the way–you may see on the JPEG-generated histogram that you have blown highlights and/or blocked shadows–but once you work on the raw image, you might find that some (not necessarily all!) of these areas are actually recoverable, despite what the histogram said. [HINT: Set your in-camera contrast to the lowest possible setting–this gets your JPEG histogram as close as possible to what the camera really sees in raw… as some tests have shown that, shooting in raw, you might actually have over 1/2 stop extra wiggle room in the highlights and up to 2 stops wiggle room in the shadows, beyond what your JPEG histogram might show on the LCD.]

That means that with your camera set only to JPEG and not to RAW, what you are essentially doing is relinquishing post-processing control of your image to the menu settings you set on your camera. This might actually be a good idea for some people–if you shoot 500 images at a sports venue, for example, you don’t have time to post-process all those images individually and maybe they need to be sent off immediately to your editor or for online posting… or if you are in the initial part of your learning curve and you want to shoot a lot… or if you never enlarge your images… or you only ever post online–these may all be good reasons to stick to JPEGs. In fact, Ken Rockwell is one contrarian voice in the wilderness who actually advocates using JPEG files for most people and you can read his arguments here as well as a reader response to his views here.

The Raw Advantage

So, what is the big advantage of raw? Well, if your goal is to maximize image quality and you want to have detailed control over your post-processing, then this is the way to go. You’ll get 12-14 bit information instead of the 8 bits with JPEG (8 bit = 256 tonal values…12 bit = 4096 tonal values…14 bit = 16,384 tonal values). In post-processing, you’ll be able to fine tune just about every variable you can imagine–exposure, white balance, hue, saturation, contrast, noise, sharpness, pulling detail from shadows, restoring detail to highlights, etc–all while avoiding much of the banding and muddiness that typically affects JPEGs when you try to do this (some adjustment is indeed possible in JPEGs, but not nearly as much). Now raw isn’t magic. It does have its limits, and you still need to capture the best image possible in-camera–but it is not nearly as limited as JPEG files in terms of post-capture adjustablity.

Here is one more key tip on using raw: Make sure you have software that can open the raw files! Typically, camera manufacturers include a disc with your camera with this software. Or, if you use software that is not proprietary to the camera manufacturer (Lightroom, Photoshop, Elements, for example), you may have to download the latest update to your version of that software to allow these programs to open the raw files of a newer model camera.

What do I shoot? I don’t shoot a bazillion images at a time, so I set RAW + JPEG Fine on my Nikon. Yes, it is a bit redundant as the raw file contains a small JPEG that could be extracted, but with that additional +JPEG setting I have large-sized JPEGs immediately available for a quick preview, a baseline of what the images could potentially look like, and I have files I can easily send electronically or post online with minimal post-processing.

I do, however, spend most of my time with the raw files. Out of, say, 100 images on a particular landscape or cityscape shoot, I might choose five to post-process and I’ll do that manually from the raw files for maximum image quality. My basic workflow: I open the raw files in Lightroom, do some basic tweaks, then export them as TIFFs. I further refine the TIFFs in Photoshop, then save a finished version for printing in sRGB JPEG format. So, I end up with four files of each “keeper”: the original RAW, the minimally-worked TIFF converted from Lightroom, the final, worked TIFF from Photoshop, and the converted JPEG image ready to print. (Oct 2013 UPDATE: Using the Epson 3880, I now just print directly from the final TIFF, which I have worked in the Adobe color space. I no longer convert to JPEG/sRGB.) You will surely develop a flow that works for you.

So, in the end, whether to shoot raw or JPEG is ultimately a personal choice based on what and how you shoot and to where your images are ultimately destined.

(If you would like to explore this further, Thom Hogan has a more in-depth essay you might want to check out: Raw or JPEG?)