Disclamer: This comparison uses specific raw files from specific cameras. You should not assume that your results with the cameras you use will be the same! Also, all images are different and may behave differently when converted.

Shooting in Raw

For years now, I have been enthusiastically evangelical about shooting exclusively in RAW mode for shots that "matter." I, myself, have certainly saved quite a few badly exposed images from the trash bin because I happened to be shooting RAW. In theory, shooting in RAW offers as much as two stops in exposure latitude -- in both overexposure and underexposure (or 2.5 stops in each direction, depending on which RAW converter you use). In practice, the real latitude is less than the theoretical limit, but it is certainly much better than what happens if you shoot in JPG. If you expose poorly while shooting in JPG, you are either dead (overexposure) or crippled (underexposure). Granted, we should all be practicing to get our exposures to be dead-on, but no one gets perfect exposures all the time, and with white balance as another variable you have to worry about, RAW is definitely the way to go, because you can shoot first and white balance later.

So let's assume that I have convinced you to shoot in RAW. Now what?

At first, there appears to be a whole lot of additional workflow that comes with the decision, and in fact, the perception of additional work is enough to have scared more than one person I know away from shooting in RAW. But it's not really that bad. For one thing, you can just batch convert all of your images using the included conversion software. The software packages that come with digital cameras typically produce images (upon conversion) that are nearly identical to what you might get directly out of the camera if you had been shooting in JPG (at least, this is what I've discovered when shooting with Canon dSLRs). If you are afraid of RAW workflow, you can shoot in RAW anyway and then batch convert all of your images to the relative safety of JPGs or TIFs. File away your RAW files and go back to them when you are comfortable dealing with them. And because the software for RAW conversion keeps changing, the images you have just taken can actually get better as newer versions of the conversion software are released.

RAW Converters Are All Different

Different RAW converters produce different outputs, given a RAW file. I assembled this page so you can take a look at the results of various RAW converters when run on typical underwater scenes. As you will see, if you only stick to one RAW converter, you may not always get a better result than if you had shot only JPG in the first place (this surprised me very much).

In this comparison, we'll be looking at conversions of RAW files from the Canon EOS D60, Canon EOS 1Ds, and Canon EOS 1D Mk II, converted with the following programs:

• Canon EOSViewer 1.0 (comes with Canon dSLRs)
• Canon Digital Photo Professional 1.0 (newly released, works with Canon EOS 1D, 1D Mk II, and 1Ds only, with support for 10D and Digital Rebel planned in the future)
• Adobe Photoshop CS, with Camera Raw 2.2 update
• CaptureOne v1.2 and v3.5

Sample Conversions, and Discussion

The first image I'd like to look at is a photo of Darwin's resident bottlenose dolphin, which I shot in the Galapagos with a Canon EOS 1Ds and 15mm fish-eye lens (full-frame). The sun is just visible in the top of the frame, and as we digital shooters have come to know, with current digital cameras, the sun is an evil entity whose sole purpose in the heavens is to nuke into obscurity certain portions of the frame.

Previously, I primarily used CaptureOne for all of my RAW conversions, and as a result, I avoided the sun like a plague because sunballs in CaptureOne's conversions were absolutely atrocious. Adobe Photoshop CS' conversions were no better, the sun resembling a jaggy white blob in the image. And what's what that horrible turquoise surrounding sunballs?

One day, I started shooting in RAW+JPG mode (wherein a JPG image is stored in addition to the RAW image), and noticed that the JPG versions of my images containing a sunball were better than their respective converted RAW versions.

"Uh oh... " I thought. Could JPG be better than RAW in some circumstances? I was confused, and I was afraid of the ridicule I would be sure to receive after announcing such a finding, especially from folks like Jim Watt and Dave Haas, who are still shooting only in JPG.

After a few days, I decided to try converting the RAW files using Canon's software. After all, Canon created both the firmware in the camera and the RAW converters in the bundled software; the results should be similar, right? I did the new conversions, and after a cursory inspection, I was pleased to conclude that the results were nearly identical. Indeed, RAW images with the sun in them could at least look as good as the JPG versions did, and one would still get all of the benefits of having shot in RAW originally (e.g. lack of compression artifacts, variable white-balance, exposure latitude, cool-factor for being a photo nerd, etc.). And most importantly, I was going to be spared the ridicule I might have gotten if JPG had turned out to be better for anything.

Below are RAW conversions of the aforementioned dolphin shot. You can judge for yourselves, but I personally think that the sunballs in the Photoshop and CaptureOne conversions are absolute shit. CaptureOne performs better when you underexpose until the "red" underexposure warning goes away, but then the dolphin ends up looking too dark, and you'd have to pull out two different versions and composite digitally to get acceptable results. I like what Canon's software did. I also included conversions with the Canon software underexposed by 2 stops, and noticed that this created barfy turquoise halos similar to what Photoshop and CaptureOne produce.

I conclude from this that the default conversion curve in Photoshop and CaptureOne is bad for very bright areas that are overexposed (like the areas around a sunball). It must keep brightness values relatively low until a certain threshold is reached, after which it just decides that the color value is white, which would result in the visible step from the turquoise to absolute white.

The Canon software output is more smooth. Will someone please tell me what is actually happening, in more technical jargon? I'd like to know.

All images were converted from the RAW file and then converted from AdobeRGB to the sRGB colorspace, to match most closely the highest % of uncalibrated monitors out there.

Click on a thumbnail for a larger version of the image. All large images will open in their own window, so you can compare them by clicking on multiple images.

Canon EOSViewer 1.0

Canon EOSViewer 1.0 EV -2.0

Canon Digital Photo Professional 1.0

Canon Digital Photo Professional 1.0 EV -2.0

Adobe Photoshop CS - Shadow: 5

CaptureOne 1.2

CaptureOne 3.5 -EV until no red

Here's a crop of the image, near the partial sunball. Again, click on thumbnails to see larger versions.

Canon EOSViewer 1.0

Canon EOSViewer 1.0 EV -2.0

Canon Digital Photo Professional 1.0

Canon Digital Photo Professional 1.0 EV -2.0

Adobe Photoshop CS - Shadow: 5

CaptureOne 1.2

CaptureOne 3.5 -EV until no red

Interestingly, not all sunballs behave this way. It's only the sunballs that have relatively smooth gradients that end up looking SO BAD after conversion with CaptureOne or Photoshop CS. Here's an example where the outputs are more comparable. Again, you'll have to make your own judgment about which one is the best. My point is only to show you that there can be a big difference in which one works for you. In this case, I might pick the Canon version(s) or an underexposed CaptureOne conversion (the last in the bunch).

Canon EOSViewer 1.0

Canon Digital Photo Professional 1.0

Adobe Photoshop CS - Shadow: 5

Adobe Photoshop CS - Shadow: 0

CaptureOne 1.2

CaptureOne 3.5 -EV until no red

Again, a crop of the sunball area:

Canon EOSViewer 1.0

Canon Digital Photo Professional 1.0

Adobe Photoshop CS - Shadow: 5

Adobe Photoshop CS - Shadow: 0

CaptureOne 1.2

CaptureOne 3.5 -EV until no red

Another example of a sunball, this time obscured by a gorgonian. None of the sunballs are any good, but the Canon ones are less bad. Sort of like the state of politics here in America.

JPG from Camera

Canon EOSViewer 1.0

Canon Digital Photo Professional 1.0

Adobe Photoshop CS - Shadow: 5

Adobe Photoshop CS - Shadow: 0

CaptureOne 1.2

CaptureOne 3.5 -EV until no red

You know the drill. Another crop:

JPG from Camera

Canon EOSViewer 1.0

Canon Digital Photo Professional 1.0

Adobe Photoshop CS - Shadow: 5

Adobe Photoshop CS - Shadow: 0

CaptureOne 1.2

CaptureOne 3.5 -EV until no red

And now, for something completely different.

I have a problem with Adobe Photoshop CS' conversion of shadow detail in high ISO images.

By default, Photoshop's default "Shadows" level is set to 5, and when you bring it back to 0, you typically get a result that lacks contrast, especially in dark areas (duh). When you convert an image with a lot of shadow detail with the default settings, you get a horrible blotchy mess in the shadows. Sliding around the Shadows control gives you a nice range of boring to unacceptable, but at least you get to pick which one you'd prefer.

This is a photo of my friend, Zandra. It was shot with a Canon EOS 1D Mk II, at ISO 1250, f2.8, 1/40 sec. Look at the shadows in her coat.

Canon EOSViewer 1.0

Canon Digital Photo Professional 1.0

Adobe Photoshop CS - Shadow: 5

Adobe Photoshop CS - Shadow: 0

CaptureOne 3.5

In the cropped area, you can clearly see the blotchy mess that Photoshop creates by default, with Shadows set to 5. If you set the Shadows slider to 0, you get something that is too light. I think CaptureOne does the best job, but the Canon versions aren't so bad, either.

Canon EOSViewer 1.0

Canon Digital Photo Professional 1.0

Adobe Photoshop CS - Shadow: 5

Adobe Photoshop CS - Shadow: 0

CaptureOne 3.5

Closing Notes

What did we learn from this exercise? Try all of the RAW converters available. The Canon/Nikon/Fuji converters are free and come with your cameras, and since these do the best job with sunballs (in my opinion), you're in luck as an underwater photographer. But the other converters can be worth your money, especially for easy chromatic aberration correction (Adobe Photoshop CS) and for a great workflow (CaptureOne).

I tend to prefer CaptureOne over the others for most RAW conversions, but whenever I see a sunball in my image, I don't even bother trying to use it. Instead, I go directly to Canon's bundled conversion software.

If you have any questions or want to discuss RAW conversion, please SEARCH or POST in our "Image Processing, Printing, and Storage" forum category!

Author: Eric H Cheng, Editor, Wetpixel.com - http://echeng.com
Date: Friday, May 28, 2004