Steve Perry Offline Upload & Sell: Off
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Note - see the top of page 9 for the "answer" to all of this, such as it is.
OK, so I need a couple volunteers who have either a D5 or D500 to preform an easy test.
Here’s the thing, I think there may be something wrong (or at least different) with the way the D5/D500 handle Dynamic AF. I’m working on a project and while doing some tests I ran across what I think may be a bug in the firmware. I’m hoping it’s just something bone-headed on my part, but we’ll see.
First, the way Dynamic AF is supposed to work - or at least has worked up to this point:
The general idea is that you have a primary AF point and you lock on using that. Once locked on, if the primary AF point falls off the subject, another point in the group will pick it up and continue to track your initial subject (unless it falls out of the chosen dynamic AF field of course) .
If I use my D810 or D7200 this behavior is easy to test for and see in action. I can focus on an object - and holding down my AF-On button - adjust my composition, bringing the primary AF point OFF the subject and pointing it towards the background, but still keeping the original subject inside the AF field. When I do this, the camera holds focus on the first subject and ignores what’s under the main AF point (unless the secondary AF points can’t get a lock, then it will switch to the main point again).
However, when testing this behavior with the D5/D500 I discovered BOTH cameras will let go of the main subject and focus on whatever is under the main AF point instead. So, this essentially makes Dynamic AF in the D5/D500 useless - it’s just like using single point since when the main AF point goes off target it refocuses on whatever is under it - even if the initial subject is still under the Dynamic AF area. I’ve seen this with both stills and action shots.
So, I want to see if this is really an issue or just something odd with my two cameras, although I don’t think two different bodies would have the same problem.
Testing it is pretty easy. Switch your camera to AF-C and D153 (happens with every dynamic mode, 153 is easiest for testing) . Set your primary AF point to the center point. Now, you need a good foreground target in front of an AF-friendly background (the camera will stick to the subject if the main AF point doesn’t have anything to get a lock on, so blue sky shooters may never see this issue). For testing purposes, you can use a setup like I have in the photos below. I’m at 50mm about 6 feet from the table, the stuff in the back is about 2.5 feet behind the front target. All are very easy for the AF system to lock on to.
Now, focus on the foreground target with the primary AF point and, holding down the AF-On button (or maintain a half press of the shutter release), move the main AF point off the first target and point it towards the background. The camera should stick with the first target indefinitely, but my cameras both jump to the background after a very short delay (In fact, it’s the delay you set under custom setting A3 - but that shouldn’t come into play unless the target completely leaves the AF area which is doesn’t in this case).
I can do identical tests with my D810 and D7200 and they always stick with the first target, the D5 and D500 always jump away.
I’ve contacted Nikon support about this and based on my conversation thus far, I don’t think they even realize the D5/D500 have d153 and an option. They have been utterly worthless.
So, if you don’t mind can you test your camera and post the results? Also, maybe post your firmware version as well (Under the Setup Menu, all the way down). Both of my bodies have the latest firmware.
Below is an example from the D5 and D810 (screen shots from the camera). Note that I have duplicated this in the field over and over, so it’s not just something I see under test conditions.
Like I say, hopefully it's just something bone-headed on my part (it happens) or I'm missing something.
D5 with d153 and center AF point selected - works as expected
D5 with d153, moving off of center and the camera fails to stay on first target
Same test, D810 - center AF point, D51, works as expected
D810, D51, now moving off target, the D810 switches AF points and stays with first target as expected.
Edited on Mar 15, 2017 at 08:07 PM · View previous versions
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