A RAW Conversion Primer - 3/2/2007

The idea of shooting in RAW is pretty daunting to new owners of dSLRs and Advanced Compacts that support RAW. It’s a new world and it takes a different approach than you might be used to with the traditional .jpg file. My purpose in writing this is to share what I've learned, help readers wade through some of the muck, and gain an understanding what they need to know to get started shooting in RAW and converting files. I started shooting RAW shortly after I bought my dSLR. The reason I did was that I found I really don’t care for the decisions my 20D makes when producing .jpg files. Over the past year and half I've tested a lot of different RAW conversion tools. I think I have amassed at least enough knowledge to have a good understanding of what's available and where the market seems to be headed. I was driven by my mad desire to find a tool that would minimize my time in front of the computer. I'm going to assume you've read Zenon and Cathy's article on Color Theory, White Balance and RAW. If you have, then you already know what RAW is and about its benefits. I will only expand on their article where I think it's necessary.

Variety of tools

This is where the confusion begins, at least for me it did. There are so many tools available and so many opinions on what's good and what's not, that many people choose stick to .jpg files. I can't really blame them. Most manufacturers offer conversion tools for their own cameras. Many people find them weak after just a short time. There are lots of 3rd party tools available with cost varying from free to hundreds of dollars (US). They each have different strengths and weaknesses. This is not a review of tools. That being the case, I'm only mentioning a few that I know of, or have personally tried out. The good news is that most vendors offer a free 30 day trial. So if one product isn’t to your liking, just download another and try it. In fact, download 3 or 4 of them at the same time and do side by comparisons. I highly recommend this approach because one tool may be better suited for your workflow over another. What works well for me, may not be your cup of tea.

Adding to the confusion are the proprietary formats of RAW files. Each camera manufacturer has their own file format. What makes it more confusing is that they often customize the RAW format to each new camera. This means that when they release a new camera, they also release a new RAW format. Since they do not publicly share the formatting info, 3rd parties are forced to reverse engineer the new formats to be compatible with their software. In an attempt to alleviate this Adobe has created the Digital Negative format (.dng). While manufacturers have yet to entertain the use of this format, Adobe is encouraging photographers to convert their RAW files to .dng before processing. There is also a movement called OpenRaw, which seeks to encourage camera companies to make their RAW format data freely available. As I’ve waded through the dense jungle of the RAW world, I’m finding that I’m becoming a supporter of OpenRaw.

Manufacturer specific software includes Canon Digital Photo Professional and Nikon Capture. As of this writing, I’m not sure if others are including software with their cameras. Popular 3rd Party tools are that are available include Capture 1, Bibble, Adobe Lightroom (beta), Adobe Camera Raw, UFRaw, Apple Aperture, SilkyPix, and Breeze Browser Pro. While very popular, Raw Shooter is not discussed in this article because its supported lifespan is limited.

Pro vs. Lite tools

Several vendors, such as Phase One (Capture 1) and Bibble, offer two versions of their software, Pro and Lite.

The pro versions offer additional, professional type options such as work queues, support for multithreading, tethered camera support, Photoshop plugins, and more controls over some aspects of the image. They will also be quite a bit more expensive. Lite versions are geared to the hobbyist and often have more than enough tools to do good conversion work.

Direction of industry

The typical workflow of a person who uses RAW is convert a RAW file into a .tif or .jpg and finish the detail work in a photo editor like Photoshop. Then later they will catalog and organize the files with yet a third tool like ACDSee or iMatch. A new concept is emerging in the RAW conversion and digital darkroom market. The idea is that one tool can and should be used to organize, convert, edit, and print. This concept nearly eliminates the need for a traditional photo editor and separate DAM (digital asset management) program in normal photo processing. As an amateur, I don’t completely subscribe to this concept, but I can certainly see its benefits. Pros that shoot weddings and large events would gain huge benefits from this because it would greatly speed up work flow.

Adobe Lightroom is attempting to lead the way with this concept (though it still has a long way to go) and others are close behind. ACDSee has added RAW conversion capability to their Pro product, as well as a photo editor as a plugin. Capture 1 has (at least in the past) offered a bundle of C1 w/ACDSee. Bibble has written a plugin interface to allow 3rd parties to enhance its capabilities. Most converters now have curves, histograms, spot healing tools, and additional color correction capability. That was not the case a year ago. Even decent noise reduction has been added to the better tools. Using Lightroom or Bibble I've been able to accomplish 95% of my processing, leaving very little work to do in a photo editor. We're not quite there yet, but I suspect in a year or two most products will handle the majority of what photographers need to truly speed up workflow.

Common features of RAW conversion tools

Most conversion tools have a set of basic tools that are common across the board. These include white balance, exposure, saturation, hue, contrast, and sometimes fill light. As mentioned previously, many vendors are including more sophisticated tools such as curves, live histograms, and color correction. Every conversion tool implements these tools a little differently. As such, level of control can vary from tool to tool. This could produce slightly different results when comparing tools side by side. Side by side comparisons I’ve read lead me to believe that this is entirely subjective.

RAW processing and conversion

Now let’s convert a file (Finally he gets to the good part!). I'm going to use Bibble in the examples because that's what I've settled on for my chosen tool. The basics will work the same in any conversion tool though. Even some of the advanced tools have equivalents in other conversion software. I'm going to use a photo that is not the most appealing, but will help demonstrate the basics of RAW conversion.

Screen shot #1 is a photo of the Milwaukee Art Museum I took at about 6:30 am in Oct. of ‘05. It was one of the more stunning sunrises I’ve been able to capture. For a few brief minutes, the museum and all the other buildings in the area were bathed in the most incredible hue of lavender. Notice that all the settings in the tool palate on the right are off or set to 0 (Screen Shot #1b). The file is pretty much just the plain RAW file. There is a little color but on the whole it’s kind of flat. My job is to bring out what I saw that morning.

Screen Shot #1

Screen Shot #1b

The first adjustment we want to make is to the white balance. Notice that in the screen shot above this is set to “As Shot”. This means that it is displaying with the WB setting that was used in the camera at the time the photo was made. Even though the camera does not process the RAW file using the WB setting, it does attach that information to the metadata of the file so that it can be used during RAW processing. I leave my camera set to Auto WB all of the time. If the “As Shot” setting does not work well, I simply change the WB setting while in Bibble. Screen Shot #2 below is a screen shot of how the setting of “Sunny” (Screen Shot #2b) will affect the image. Bleah! The museum is nice and white. But this is not how things looked that morning. It’s also not very appealing. This is where the power of WB comes in. As shown in Zenon and Cathy’s article, the higher the Kelvin temperature, the warmer the color cast. The best way to see this is to practice moving the slider back and forth. You’ll easily see what the effect is and why correct white balance is so critical to a good digital photo. You can also use the drop down list and try common presets that match those from the camera, such as tungsten and fluorescent. If you have an object in the photo that is white or middle grey, use the eye dropper to set custom WB. I do this whenever possible as it generally yields the best results. For this photo, notice the Kelvin slider has moved the right a little with the “Sunny” setting. Sometimes it’s desirable to have a warmer feel, sometime a colder feel. In this case a colder temp gives the desired effect, so I’m going to stick with the “As Shot” setting.

Screen Shot #2

Screen Shot #2b

In the sample below (Screen Shot #3, 3b) I’ve made three adjustments; saturation, luminance, and curves. With curves, I just want to bump the contrast a little without raising the highlights. Saturation and luminance add some punch to the color. Be careful. A little goes a long way. There may be a temptation to push the image too far. Additionally there are sliders for HR (highlight recovery), Fill light, Exposure, and Contrast. These are typically standard features of RAW tools. The exposure is pretty good in this image so I don’t see any need for adjusting any of these right now. You’ll also notice an Auto Level checkbox and something called “Perfectly Clear”. The first is self explanatory. Just like auto levels in PS, sometimes it helps, sometimes not. Perfectly Clear is a patented auto levels technology from Authentech Images. You might find general auto levels on other RAW software, but I don’t think you’ll find Perfectly Clear. So far I’m finding that Perfectly Clear doesn’t really help me much. Still, I almost always try both of them to see what the effect is.

Screen Shot #3

Screen Shot #3b

The changes in the next screen (Screen Shot #4) are a little more subtle. Save for sharpening, I used a couple of Bibble plugins to achieve them (Screen Shot #4b). I used the built in sharpen tool to sharpen the image a bit. Most RAW conversion tools provide some sort of sharpening. The HueyPro (the tool's name has since changed to “Roy” for legal reasons) color conversion plugin gives me very granular control over the hue and saturation of the colors red, yellow, green, cyan, blue, and magenta. The SadiePro plugin gives tighter control over general color saturation by adjusting luminance levels separately in the shadows, midrange, and highlights. Since this is only to show what can be done, I won’t go into to detail on the adjustments I made. Note that the image has a bit more life to it after I made these changes. While these plugins are specific to Bibble, I know that Adobe Lightroom has equivalent controls for saturation and luminance. I’m not sure about Capture 1 Pro or other software, but I won’t be surprised to see these features added to other packages if they are not already.

Screen Shot #4

Screen Shot #4b

Screen shot #5 shows spot healing, essentially the equivalent of cloning. Just ignore the color change in this example. I was experimenting with HueyPro a bit and really pushed the lavender look. Spot Healing is a feature that’s starting to show up in a lot of RAW conversion software. It works OK, but I personally find that good old cloning is faster and more accurate. Still, for one or two dust spots it’s handy.

Screen Shot #5

At this point I’ve done a lot of work so I’ll take a minute a review the image. I’ll zoom in to 100% and scroll through it to see what else needs my attention. I’m going to bump the contrast just a little with the contrast slider. There is also a little bit of noise in the sky. I normally use Neat Image for noise clean up. However Bibble includes a scaled down version of Noise Ninja (Screen Shot #6). It does a decent job on light noise and saves me a step later after conversion. For the big jobs I still use Neat Image. Most of the RAW converters now include some sort of noise reduction. Most of them fall flat. Noise Ninja and Neat Image pretty much own the noise reduction market. It was a wise move for Bibble to license Noise Ninja. The Pro version allows owners of the full version of Noise Ninja to plugin to Bibble.

Screen Shot #6

Cropping and straightening are standard tools in Bibble and most other conversion software. They generally work well and I’m finding that I am using them a lot. There’s no need to straighten this photo. But for this tutorial I’ll crop the photo (Screen Shot #7, 7b). I can do a free form crop or constrain it to a particular aspect ratio. I can also customize my own sizes. I added the 6x9 that I’m using here.

Screen Shot #7
Screen Shot #7b

The final step in the process is the conversion itself. You might be thinking about all of the destructive edits I just made to this file. And that I violated a processing “rule” in that I sharpened well before the last step in the process. Never fear with RAW. You never actually edit the RAW file itself. I would offer one caution though. Just like a .tiff or .jpg, one change can have a dramatic effect on other changes, especially when making adjustments that affect color. The RAW adjustments are saved in a separate file that is specific to the photo you’re working on. The method they use for this varies by vendor. The best analogy I can refer to is layers. Many people use layers in PS to make adjustments to the photo without actually changing the original file. What’s more important to understand is that while the changes are previewing “live” on your screen, they are not actually applied until you save or convert the file into a .tif or .jpg. In Bibble it’s as simple as going to “File”, then “Save As”. Lightroom is using a concept called “Export”. Camera RAW and other converters that have a PS Plugin let you simply switch to PS and save the file in whatever format you like. The more powerful converters allow you to also choose the color space that you want the file to be in. Screen Shot #8 below is my final photo. True, it's a bit unrealistic looking, but I wanted to show what can be done with RAW conversion.

Screen Shot #8

The entire process on this photo probably only took 5 minutes. Most photos only take minute or two to process. Sometimes I’ll spend as long as an hour working a shot. Many of the software packages allow you to batch process. That is, get the settings the way you want them for one photo, then apply them all photos in a folder or rating group. What’s a rating group? I can rate photos with stars, from 1 – 5 and filter by the rating so that I only see the one I want to work on first (5 stars for example), and even delete the ones I give only 1 star to. Another feature becoming common is the ability to customize the interface. You can usually display only the tools used the most and change the layout of the components to suit your workflow.

Conclusion

So now you know how easy this really is. At first it may seem a bit overwhelming and even time consuming. After you’ve done a few you’ll find that it can actually be faster than traditionally processing a .jpg off of the camera. You will most certainly see how powerful using RAW is and how much more control you have over the photo. To get started I recommend that you shoot in RAW & JPG if your camera allows it. That way you’ll still get what you expect from the .jpg file and you can start to experiment with the RAW files. Keep in mind that the old saying is true, “garbage in, garbage out”. While RAW offers additional control and creative options, it is not a replacement for getting the best shot possible in camera. I personally shoot only in RAW now. You may find after experimenting that RAW isn’t for you. That’s OK. There’s nothing wrong or unprofessional about shooting .jpgs. Many pros shoot only in .jpg. There are also some circumstances where shooting a .jpg is more practical. An example might be a family gathering in which you want to give a print or two to family members as they are leaving. So I think you have enough knowledge now to try a RAW file. What are you waiting for?