Z9 BIF Autofocus

[cmhammon]

I have ordered a Z8 and have a rather specific autofocus question for Z9 users, since everything I’ve seen says the autofocus performance is identical to the Z9.
I shoot a lot of osprey’s diving. When they’re in the sky, my Z7 locks on (AF-S Wide with AF sensitivity at 5), when using my 500PF without issue, but when they dive, the camera almost always transfers focus to the trees in the background no matter how much of the bird fills the viewfinder. In similar situations, did your Z9 hold lock on the subject in such an environment? If so, what were your settings for such a situation? Thanks.

 

[NorthernFocus]

My experience is that if the bird is filling more than 20 percent frame(linear dimension not pixels) I don't find any problem tracking eagles, seabirds, pelicans, ducks... Less than that then much depends on the BG. Close BG with a lot of contrast(e.g. tree trunks/branches) is the worst scenario. Motion seems to be neither here nor there if you're holding the bird in the frame. Whether the AF finds the bird's eye is hit/miss depending on angles, lighting, size of bird in the frame, type of bird, etc.

 

[Warren D]

Difficult question to answer. I also shoot diving osprey, have been doing it for 7-8 years with D500, D5, D6 and D850's and now a Z9. There is no doubt that the group AF of the dslrs with it's true close subject priority is a bit better under these conditions. The Z9 does struggle under these conditions and does prefer the background trees. There are variables, though. If there is more distance between the camera and osprey than there is between the osprey and the BG then there is a better chance the af will go to the BG. If the osprey is closer to the camera and a greater distance from the osprey to the BG then the af does better. A diving osprey is a tough subject with the sudden course corrections during the dive and the sudden speed increase toward the bottom. I think more depends on the photographer and their ability to stay on the subject.
Steve has written that the mirrorless cameras seem to like the BG more than the dslrs and I'd go along with that. The Z9 (Z8) is for the most part, better with diving osprey, I've had more keepers with the Z9 than the D850 or D6 (with the same lens, a 600 f4 EFL with 1.4tc). I typically use wide area large with a hand-off to 3D auto once subject detection engages.
As an aside, I've noticed that before the trees leaf out, the Z9 seems more likely to find the BG. Seems like the af likes bright verticals. I have found a slight rotation seems to help, I can correct it later in post.

 

[cmhammon]

My experience is that if the bird is filling more than 20 percent frame(linear dimension not pixels) I don't find any problem tracking eagles, seabirds, pelicans, ducks... Less than that then much depends on the BG. Close BG with a lot of contrast(e.g. tree trunks/branches) is the worst scenario. Motion seems to be neither here nor there if you're holding the bird in the frame. Whether the AF finds the bird's eye is hit/miss depending on angles, lighting, size of bird in the frame, type of bird, etc.

Thanks, Dan. My scenario is where the osprey is diving with a fully leafed-out bank of trees about 50-100' beyond. The bird is seldom more than a third of the viewfinder, even with the 500PF.

 

[cmhammon]

Difficult question to answer. I also shoot diving osprey, have been doing it for 7-8 years with D500, D5, D6 and D850's and now a Z9. There is no doubt that the group AF of the dslrs with it's true close subject priority is a bit better under these conditions. The Z9 does struggle under these conditions and does prefer the background trees. There are variables, though. If there is more distance between the camera and osprey than there is between the osprey and the BG then there is a better chance the af will go to the BG. If the osprey is closer to the camera and a greater distance from the osprey to the BG then the af does better. A diving osprey is a tough subject with the sudden course corrections during the dive and the sudden speed increase toward the bottom. I think more depends on the photographer and their ability to stay on the subject.
Steve has written that the mirrorless cameras seem to like the BG more than the dslrs and I'd go along with that. The Z9 (Z8) is for the most part, better with diving osprey, I've had more keepers with the Z9 than the D850 or D6 (with the same lens, a 600 f4 EFL with 1.4tc). I typically use wide area large with a hand-off to 3D auto once subject detection engages.
As an aside, I've noticed that before the trees leaf out, the Z9 seems more likely to find the BG. Seems like the af likes bright verticals. I have found a slight rotation seems to help, I can correct it later in post.

Thanks, Warren. My scenario is where the osprey is diving with a fully leafed-out bank of trees about 50-100' beyond, usually with good morning light. The shift to the background usually happens soon after the transition to the woods background and is hard to detect. FWIW, my D850 with the 500 is better at holding focus, but still isn't what I can say is reliable.

 

[Butlerkid]

I don't believe the Z8 will change this situation since the Z8 essentially focusing just like the Z9. It appears that the user needs to select the best possible AF mode, which may or may not be adequate if the bird is small in the frame.

 

[NorthernFocus]

Thanks, Dan. My scenario is where the osprey is diving with a fully leafed-out bank of trees about 50-100' beyond. The bird is seldom more than a third of the viewfinder, even with the 500PF.

If the bird is filling 1/3 of the VF laterally you should do OK. I do find that turning animal detection off tends to do better with a cluttered BG. That's with wide area L which is pretty much my go to for BIF shooting.

 

[JoelKlein]

Isn’t Dynamic medium just like group AF?

 

[thelordofthelight]

Isn’t Dynamic medium just like group AF?

Nope..not at all..the closest to group is wide area L without subject tracking and even that's not 100% like group AF mode on the DSLRs.

 

[thelordofthelight]

I have ordered a Z8 and have a rather specific autofocus question for Z9 users, since everything I’ve seen says the autofocus performance is identical to the Z9.
I shoot a lot of osprey’s diving. When they’re in the sky, my Z7 locks on (AF-S Wide with AF sensitivity at 5), when using my 500PF without issue, but when they dive, the camera almost always transfers focus to the trees in the background no matter how much of the bird fills the viewfinder. In similar situations, did your Z9 hold lock on the subject in such an environment? If so, what were your settings for such a situation? Thanks.

Most of the Z9 users had some challenges with photographing birds against busy BG initially but this has changed significantly post Fw 2.1 onwards and only getting better. Post 2.1, i have hardly faced this problem with bigger birds and in the rare occassion that the camera loses focus, pumping the AF button has solved the problem more often than not. Where the Z9 struggles still is with small birds with less contrast, like swallows and Swift's against busy backgrounds. I photograph black kites a lot and these birds have a dull shade and yet I've not faced nuchproblems with the Z9, again after fw2.1.