Reader Question: Nikon D850 Monochrome Autofocus
Related: black and white, digital sensor, focusing, Live View, Nikon, Nikon D850 monochrome, Nikon DSLR, reader comment, videos by Lloyd
re: monochrome
See my review of the Nikon D850 monochrome.
Alexander R writes:
I recently had MaxMax.com convert my D850 to Monochrome after seeing both his samples and your in-depth review about it. I LOVE the sensor, and I couldn’t be happier with the results.
I have had an issue getting the autofocus to calibrate; when I attach a lens to the body, the initial autofocus (through the viewfinder, not through Live View) is off by a pretty sizable margin. When I try to calibrate it, I can’t get Nikon’s proprietary AF Fine-Tune to record any values. I was able to manually enter some, which allowed me to get pretty close (90-95% accuracy through the viewfinder), but with that beautiful sensor, it’s a shame to have it be anything short of precise.
I’m curious if 1) you had any of these AF issues when you were testing the D850 Monochrome, 2) what you did to alleviate it if you did, and 3) if you’ve had any experience calibrating autofocus lenses on the D850 and any suggestions you might have. Thanks for your time, I thoroughly enjoy your insights on your website.
...after my response...
I mainly do documentary work, so Live View isn’t really an option, I guess I’ll just have to work around the focus limitations wide open with fast primes. Thanks again.
DIGLLOYD: an unmodified Nikon D850 has AF accuracy issues, given that the viewfinder uses a separate optical path. Still, it was usable for a lot of stuff.
A modified D850, seeing as much or more infrared as visible light and also with no sensor cover glass… that’s a non-starter for focus accuracy. Infrared and deep red have substantially different focus than most of the visible light spectrum. In other words, you are tasking the camera AF system with an impossible task! Live View is mandatory for accurate focus.
Shooting the D850m unfiltered results in a messy visible + IR result. At the least, filter off the infrared and then AF results may improve—possibly.
And it is possible to shoot the camera with AF using Live View; see Video: PERFECT focus using the rear LCD Live View + focusing loupe
