Z50 Autofocus Experiences

I purchased my Z50 for many reasons — silent shooting, exposure preview, fast continuous burst speed, good video capabilities — but one primary reason: Eye Autofocus. The other features are great, but I can get by without them on my DSLRs that offer the same or higher resolution and burst speed. Eye AF is supposed to be a transformative feature that delivers more images in focus, especially during fast action. I know Nikon’s implementation isn’t class-leading and the Z50’s implementation is the lowest-end, but I had to try it. Could it really be that bad? Is there anything good about it?

Before I get into details, let’s talk about my use cases. I shoot a lot of subjects that are moving — my kids playing outside, soccer games, the dog running around, birds and other animals. Getting crisp shots of subjects in motion is difficult, but Eye AF promises to make it easier by focusing on what tends to be the most important part of a living subject: the eyes. It also promises to make portraiture of static subjects easier by guaranteeing sharp eyes every time. In theory it automates the photography of living subjects so I just have to worry about framing.

The Hits & Misses of Eye AF

The Z50 supports Eye AF for humans and animals in Auto area mode. When an eye is detected, it’s focused on and marked with a yellow box in the live view. If two eyes are found, the left and right sides of the multi selector can be used to switch from one to another. If eyes can’t be detected or are lost, focus falls back to face detection or the closest thing to the camera. Human and Animal Eye AF are separate modes that cannot work at the same time. The Z50, Z6, and Z7 only support cats and dogs, but the higher end Z9 also supports birds.

I’m not a huge fan of Auto area mode on my DSLRs but I have to use it if I want Eye AF to work. It makes sense: if the camera can automatically detect the most important part of a living subject and let me reframe as needed, then I don’t need much control. I must say it was really exciting the first time those yellow boxes showed up over eyes. It was amazing that the camera could find the eyes so quickly, something that usually takes some effort when I do it myself. The eye tracking worked even if the subject moved side to side a bit. It was pretty awesome and is something that could be very useful, for static subjects at least.

The images above were achieved with perfect or near-perfect eye or face-detect autofocus

My experience with moving subjects was mixed. Prior to a recent firmware update, the eye focus would frequently lag behind the boys or the dog if I was panning with them resulting in mostly unfocused shots. In many of these shots I was using adapted lenses which do not perform as well anyway, but I saw a similar lack of consistency with the 16 – 50mm native lens as well. After installing the November 2021 v2.2 firmware that includes “Improved face/eye detection performance” I’ve seen an improvement. I don’t think it’s Sony or Canon-level, but it’s now finding eyes and tracking them much more consistently.

Even after the firmware update, fast moving subjects are still a challenge. While it initially finds the eye more frequently than before, it still loses it when the subject moves quickly. It does try to keep up, but I often see Eye AF focus indicators offset from where the eyes were a fraction of a second before, like on the cheek or on the side of the body. This happens because the autofocus system and lens cannot keep up as the subject moves.

These images represent situations where eye-autofocus tried, but failed to capture the subject, often falling back to area autofocus. These are still good images but not because of successful eye autofocus.

Even for static subjects, Eye AF can be hit and miss. Sometimes it only catches the eye when the subject fills most of the frame, but other times it catches it further away. Sometimes it defocuses the eye after it has found focus, even though the subject hasn’t moved. This might be due to being in continuous autofocus mode, but my DSLRs stay focused in this mode when the subject isn’t moving so it shouldn’t be a problem.

When it does lock focus, it allows a bit of reframing, but not as much as I’d like, losing the eye toward the outer 25% of the frame. It also detects things that are not eyes, such as busy patterns on linens, tree branches, and even ears. I could understand things that are circular but these are just complex patterns.

Adapted Lenses

The FTZ adapter works with most of my lenses. They focus more slowly than on my DSLRs (which I knew), but they otherwise work the same. Quality is just as good as on a DSLR once they get focused. While they negate the size benefits of mirrorless and look a bit more ridiculous than usual, the Z50 is still balanced enough even with my huge 150 – 600mm. I do think that the speed of adapted lenses causes some issues in lower light or longer focal lengths – sometimes they get stuck and refuse to focus unless I manually adjust them. The same doesn’t happen in better light / shorter focal lengths and doesn’t seem to happen with the native Z lens.

One of the adapted lenses I’ve been using is the 70 – 300mm AF-P DX that came with my eBay auction. It’s the only DX (crop sensor) lens I’ve ever owned and its pretty nice. It’s not a constant aperture, but it’s lighter than my 28 – 300mm full frame lens, it focuses quickly and almost silently, it’s sharp, and it has a fancy electronic focus ring. It fits right in with the Z50 and I might even use it with my D500.

Overall adapted lenses struggle more with autofocus than the native Z lens, especially for fast moving subjects, but I was aware of that limitation when I bought the camera. I can still get good shots, but they are less likely with adapted glass and active subjects.

Regular Autofocus & Tracking

Outside of Auto Eye AF, the Z50 includes single point, dynamic area, wide small, and wide large modes. The dynamic area is not customizable like my D500 and D750 and seems to be more like group area on those cameras. The two wide modes seem more like dynamic area on my DSLRs but remind me of Live View focusing because they are big rectangles. I’ve used single point for bird photography and I feel that I’m getting about the same performance as my D500. That’s good.

Unlike my DSLRs, there is no 3D Tracking mode where I can put a single point on a subject and track it automatically and easily move the point at any time. It has a subject tracking mode that is kind of like 3D Tracking but isn’t very good. It only works in Auto area mode and requires two presses of the OK button to select and track the subject. A different button is required to cancel it. The version 2.0 firmware allows it to be assigned to a button so that it’s only enabled when that button is pressed. This makes it better but still not as straightforward as regular 3D tracking.

Just to prove that regular autofocus works, these were taken with either auto mode or single point autofocus, despite me continuously forgetting that the Z50 does not support birds for animal autofocus.

The bigger problem with subject tracking is that it’s just not very good. It doesn’t track very quickly and keeps focusing and unfocusing the subject even when it’s not moving that much. It loses the subject if it goes near the edge of the frame, instead picking up whatever is closest to the camera. After that it basically never grabs that subject again until it’s reset. I can get used to the interface, but it’s not much use to me if it can’t actually track what it’s pointed at.

The Verdict So Far

When Eye AF works, it works well, and it’s faster than doing the same thing on my DSLRs because I’m not spending time trying to line up a focus point over an eye. In the cases that it picks up eyes on moving subjects and keeps focus locked, I get photos that I would otherwise miss while fiddling with my DSLRs. When it works it often returns sharper results than I get even when I’ve got my DSLR focus aligned well. I have photos with crisp eyes and eyelashes that are difficult to get , especially in motion. The consistency of success has improved a lot with the latest firmware update, which is a testament to Nikon’s continued efforts to refine a camera that is two years old.

Perhaps it’s not very fair taking many images of moving subjects with adapted lenses in lower-light indoor environments, but that’s where I take a lot of my photos. I’m not planning to dump all of my lenses for native ones so I need good performance out of adapted glass. My kids and dog aren’t going to sit still because my camera needs a minute to compose itself. Much of my life happens indoors and at higher ISOs. I wouldn’t be so hard on it if I didn’t already know how much better other systems are, and that’s the reason I did this little experiment.

Luckily there is promise on the horizon. The Z6 and Z7 Mark II models have dual CPUs that have sped up autofocus performance and improved consistency, though they are still far behind Sony and Canon’s capabilities. They have the ability to perform Eye AF in a user-selected area of the frame and have dedicated modes for animal and human subjects that make it easier to use. The Nikon Z9 has made significant progress, nearly matching the capabilities of Sony and Canon while also improving adapted lens speed to DSLR levels. Once that autofocus system trickles down into Nikon’s other cameras I think I’ll have what I need to add a mirrorless camera into my full-frame lineup.

I’ll keep the Z50 until Nikon releases something with better autofocus capabilities as I planned. I’ll continue to use it and learn about it, but I can already see areas where I’ll get photos that required more effort than before, even if it isn’t as frequently as I’d like. All in all this is worth the $900 investment.