We've had comments off and on claiming this or that about the Nikon D500 and the KIII, but a dearth of actual real-use info. I'll be the guinea-pig. :)
This will not be a quick brush-thru, I plan to update it regularly with my thoughts about the two. So here we go!
The D500 kit is a Nikkor 16-80 2.8E VR, a Nikkor 55-300 4.5-5.6G ED, and a Tamron 150-600 5.6-6.3 Di VC. Lexar XQD card in slot one. I've been using the camera daily for the past week.
Comparable lenses for my K3III will be the Pentax 16-50 PLM, Pentax 55-300 4.5-6.3 PLM, and Pentax 150-450 4.5-5.6.
First up for comparison is each with similar 55-300's. AF initially set to Group on the Nikon and Small Zone on the Pentax. This is the first time I'd had both lenses in hand to test the bodies with, my Pentax one on loan until two days ago, and one I've almost never used for any length of time anyway. So today they went to work shortly after sunrise, and until 9:00am this morning before the heat and humidity got too unpleasant.
First surprise: The D500 did much better in low light than I expected. The first Nikon shots were at 7am. Shooting AF-S manual with auto ISO 12800, where I had preset the limit, full open, and shutter speed 1/500. Images were detailed, clear, noisy as expected, but very recoverable. I honestly thought 12800 was going to be too high. The Pentax was preset only one stop higher at 25600, otherwise same settings using TAv. I was happy with both, and noise levels were very similar.
NOTE: I just remembered I keep the K3III underexposed by a 1/3 to a full stop much of the time. Looking, today was one of those times, exposure compensation a 1/3 stop under where I had left it. I simply forgot to change it for the early morning.
By 7:45 the sun was high enough with enough light to try some continuous shooting on some larger birds relatively close by. It was shortly thereafter I got surprise number two: The Pentax lens was absolutely solid, much faster to focus and "stickier" than the 150-450 I've been carrying for weeks. I did not expect that much difference. The Nikon did just as expected, quick focus and very good tracking. To be honest the Nikon tracked ever so slightly better than the K3III. +1 for the D500.
But then came surprise numbers 3 and 4:
I thought that I'd try tracking flying dragonflies with my Pentax, something I had no success with using the 150-450. Surprise, YES the K3III can track quick darting dragonsflies 15-30 feet out using the 55-300. I was now expecting similar success with the D500 which brings me to surprise #4: Not happening.
The Nikon would not lock focus on the same dragonflies captured successfully on the Pentax. The lens would rack in and out, but not once did it lock focus on one. That same failure happened with a plane flying in the distance, just a spec against the sky, and with a white crane far away flying above the tree line. The D500 / 55-300 combo seems to fail on small objects with low contrast against the sky. But the K3III had no problems at all, finding that same plane and the white crane, both probably even a bit smaller by then, without issue thru a half dozen shots. The K3III was way more likely (near certain) to lock focus on low contrast subjects, with the D500 more often failing than locating. That was not expected.
My guess is the more effective use of the better 307K pixel RGB sensor in the Pentax compared to the 180K in the D500 leads to a definitive improvement in recognizing the contrast differences and finding focus. Even tiny objects may be picked out more reliably. Still need to repeat and verify of course.
Tracking in general? The K3III / 55-300 combination was often quicker to locate and begin focusing on a fast flying bird, but it would sometimes take 2-3 frames to get clean-focus on them, which makes sense since I've set Release Priority. The D500 was sometimes (often) slower to find the subjects and even occasionally failed, but once acquired was better at initial focus lock from the first frame. Yes, it too is set for release priority. Honestly, both were great at tracking overall so I'm not complaining.
More to come later after I review all the images from this morning. If we have the same weather tomorrow morning I may not bother getting out to repeat the tests and see if the results are consistent, but if not Sunday I'll definitely be doing so before moving to a different lens pairing.
Early thoughts: The K3III is looking good, but lots of photos, more scenarios, and other lenses still to go.
If anyone has specific questions I'm happy to hear 'em, and will answer what I can. There's still a lot to figure out.
Oh, and one interesting observation just before I left for the day. In good light and the bird positioned right the K3III's zone-select AF very often went to the bird's eye. I don't know if I'd seen this before, but I have tweaked some settings in the past 2 weeks. Maybe it's that, perhaps it's been doing that and I haven't paid attention, or it's something better chalked up to happenstance. So another thing else to test for repeatability.
BTW, any Nikon user know the correct setting to have the rear display remain on for 30 seconds or whatever between shots?
