Nikon D850 Monochrome: Initial Example, and Frame Averaging for Ultra Low Noise (updated with comments, Sony A7R IV Potential)
Background: The Nikon D850 monochrome is a Nikon D850 with its color filter array (CFA) removed by maxmax.com. The NEF files are converted to monochrome DNG via LibRaw Monochrome2DNG and “Method B”, then processed using Adobe Camera Raw. Doing so avoids any demosaicing and thus retains full spatial resolution.
I’ve just started using the Nikon D850 monochrome, and wanted to get some sense of what it can do. One good example, plus an exploration of frame averaging, which can be used to good effect with color cameras also (already tried with the Sony A7R IV, and I might show that soon):
More about monochrome cameras.
Both pages are in diglloyd Advanced SLR and with images up to full camera resolution.
Jason W writes:
That is an incredibly impressive image Lloyd. Whatever tonality issues I saw before are not there. Spectacular quality. Rough bayer megapixel equivalent? 70? The tire image with the frame averaging is otherworldly.
The cumulative total effect of zero noise, zero debayering errors, and extreme detail without sharpening combines to create something very striking because there is no interference with the observation of the subject. It's what in the audiophile world you would call transparency. What comes across is not the artifacts of reproduction but the original object.
DIGLLOYD: exactly! (tire image is further below). It makes me want a Sony A7R IV monochrome but it will be a stretch just to afford one A7R IV as it is.
I’ll be making some images with filtration (blue, green, red, orange, yellow, etc) in the mountains soon, and I hope to make images of detail and tonality that I’ve never been able to make before—and in some cases with true 14-bit dynamic range, meaning noise-free jet-black shadow areas.
Comments continue below...
Below, no black and white camera I have ever shot can approach the qulity in this image. I show single shot and 4/9/16/32/49 frame averaging images.
Terence M writes:
Could the Sony A7RIV be converted to monochrome, would it effect the autofocus especially the Eye AF or metering?
I always preferred the traditional Silver Gelatin Fiber print to Inkjet for B&W. Digital Silver Imaging in Boston can make a Silver Gelatin B&W Fiber print from a digital file.
Since you are testing the D850 Monochrome this would be good timing to make a print and review the process, I would be willing to pay the cost of a print if your interested or have the time.
DIGLLOYD: it's a BSI sensor, so the color filter array can probably be removed as with the Nikon D850. As to a print, I’ve asked Digital Silver Imaging if they will comp me a print or two for evaluation.
Dan Llewelyn of maxmax.com who did the D850m responds:
My guess is that, yes, the Sony A7R IV can be converted. I have an A7R II sensor on my workbench now with the coverglass removed and a spare A7R II camera for testing. Today or tomorrow, I hope to try converting the A7R II to monochrome. If that goes OK, then the A7R III and, after that, the A7R IV. Sometimes R&D goes quickly and sometimes it doesn't.
I have converted the Sony A7S II to monochrome. Basically, all the features of a monochrome converted camera should work except for the obvious things like color settings and not so obvious, auto sensor cleaning is usually removed (not always) and phase detection AF is lost. Probably biggest thing is phase detection AF, but most cameras revert to contrast AF is phase AF isn't working. On some cameras, phase AF is used for continuous AF. Eye AF and metering should be fine an the A7R IV.
Metering on the A7R IV is set off the image sensor unlike the D800 which can use either the sensor in the base of the camera or the image sensor (when in Live View). With a mirrorless camera or camera in Live View, exposure and focus is set off the image sensor (unless you have a DSLR that can be set to flip the mirror back down when you take a picture in Live View).
For the cameras I do convert to monochrome, which is a limited range, APS sensors are $1,500 and full frame sensors are $2,500. Fuji and Sony cameras get an extra $100 tacked on because they are a pain to take apart. Each type of sensor requires its own R&D to figure out how to remove the coverglass, machine stainless steel fixtures to hold it and experiments to figure out the processing parameters. Out of the first 20 D800 sensors I tried converting, 4 were successful; they were costing me $2,000/sensor initially. Then there is the $100K+ equipment needed. Converting to monochrome is a pretty big deal unless you are one of the guys using sharp sticks to scrape the CFA off the sensor (those guys actually exist).
DIGLLOYD: see also Why manufacturers don't make monochrome versions of some of their cameras.