By way of background, the D800M is a Nikon D800 that's been modified by the folks at MaxMax.com to remove the Bayer color filter layer on the sensor, creating a pure monochrome camera. So, no Bayer demosiaicing artifacts, beautiful tonality, etc, etc. Now you could just go out and buy a pure monochrome camera off the shelf, in the form of Leica's M Monochrom, which I spoke about on this blog in some previous posts. Problem is, once you've bought an M Monochrom, and a few lenses, you won't have much change from say $20,000. And then, much as I love Leica's M cameras, you have a camera that is really only at its best for lenses between 35mm and 75mm, doesn't have auto-focus, etc, etc. Enter the folks at MaxMax. A lot of their work is for scientific and engineering applications, but they will build you a camera modified to pure monochrome. You can chose anything from a pocketable point-and-shoot to a top-of-the-line Nikon. Also, you can also get cameras without IR filters, UV filters, etc, etc to suit your intended use.
Lloyd's various posts go into detail about image quality, usability, etc, and are well worth the read if you're interested in monochrome work, so I won't go into any of that here. What I will talk about is the technicalities of processing the image from a camera modified to monochrome.
The problem of course is, how do you do the raw processing? Well, you if you're handy with command line options and don't mind a fairly complex multi-step process, you can persuade DCRaw to treat the image as a single color. Or you can just use a conventional raw processor such as ACR or Lightroom (or the "normal" version of AccuRaw, for that matter). Of course, the raw processor is going to think that it's still dealing with a Bayer matrix camera, and as a result is going to try to demosaic monochrome data. While the end result of that is actually not as bad as you might imagine, it isn't ideal (see later for an example).
Enter AccuRaw Monochrome. Now, to be clear, "AccuRaw" and "AccuRaw Monochrome" are separate products. AccuRaw Monochrome is dedicated to monochrome applications. It's primary target is actually conventional unmodified off-the-shelf cameras. For those cameras, AccuRaw monochrome has a special demosaicing algorithm dedicated to creating monochrome images. Because AccuRaw Monochrome is dedicated just to that, it can do a better job than conventional demosaicing algorithms that are optimized for good color results.
However, AccuRaw Monochrome also has another trick up its sleeve - it can also do true monochrome processing for a camera modified to monochrome operation such as by MaxMax. It's in this role that Lloyd Chambers was using the AccuRaw Monochrome beta. (If you'd like to be a beta tester, either with a conventional or modified camera, drop me an email to the contact address on the AccuRaw website.)
True raw processingTo demonstrate the difference that true monochrome processing makes, I'll use an image provided by the folks at MaxMax.com that was created with a D800M . Firstly, let's look at the entire image, as processed with Lightroom 5.2 and AccuRaw Monochrome Beta 0.9.1. Note that I'm using Lightroom here just because that is what is commonly used - you would get similar results from any conventional raw processor, including the normal version of AccuRaw for example.
Lightroom 5.2, default settings, saturation set to zero
AccuRaw Monochrome Beta 0.9.1, default settings
Looking at the entire image, reduced to a size that fits well on this page, there is no discernible difference between LR and AccuRaw Monochrome. The images might as well be identical - exposure is the same, overall contrast is the same, etc. However, let's take a closer look. But before we do that, hold onto the "overall contrast is the same" thought - it will be important later.
Now lets look at some 100% crops:
Lightroom 5.2, 100% crop, default settings, saturation = 1
Lightroom 5.2, 100% crop, default settings, saturation = 0
AccuRaw Monochrome beta, 100% crop, default settings
The first Lightroom crop, with saturation set to 1, clearly shows the demosaicing problem in the form of color artifacts, e.g., the "On" lettering and the "System" lettering. Setting the saturation to 0, in the second crop, sorts that (and the white balance) out. However, the artifacts are still there - there're just not as obvious. In the third crop, this from AccuRaw Monochrome, those artifacts aren't there, and the image is noticeably sharper all over.
400% cropsLooking at some crops at 400% will make what is happening more obvious:
Lightroom 5.2, 400% crop, default settings, saturation = 0
AccuRaw Monochrome beta, 100% crop, default settings
Comparing the two 400% crops, what you see is really two things - firstly, the demosaicing process is creating artifacts - you can most easily see that around the lettering. But secondly, and more subtlety, there is also a loss of micro-contrast in the LR image relative to the AccuRaw Monochrome image. E.g., take a look at the "2000i" text. And remember, the overall contrast is the same. That loss of micro-contrast makes a real difference, and is primarily why AccuRaw Monochrome's 100% crop looks much sharper all over, not just where there are artifacts.
Now I just need to work on persuading myself that a MaxMax modified Nikon Df is absolutely necessary to my artistic development.......might not be hard.....