Bighorn Headbutt Battle bewilders Z9 eye detection autofocus.

[jim0379]

I watched some Bighorn Rams testing each other near Yellowstone yestereday afternoon. The Z9 autofocus with eye detection worked very well most of the time (I remembered to switch it back to animal from bird when I left the river and the dippers.)

But I noticed early on as I watched the scuffles, that right before cranial impact, the sheep close their eyes and frequently turn their heads. And the autofocus went looking for something new. Here's a three image example. Sharp on the rear up, sharp just before impact, then not.

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Because they appeared to be staying in a fairly small area on a ridge, I switched over to manual focus with focus peaking, got it set to where I estimated the next impact would be, and fired the shutter when they reared up to go. As when I saw the autofocus detect and track the reflection of the eye of birds on a still water surface, I continue to be surprised and amazed by the capabilities and nuances of the autofocus system.

Wondering if a less twitchy setting on the A3 Focus tracking with lock-on menu would give better results if I ever get a "next time" for something like this. SO hoping there's a next time.

jim

 

[Butlerkid]

#2 is a great image!

 

[Calson]

Consider how many pixels are available to the camera's autofocus system to use to determine where an animal's eyes are in the frame. I was photographing a vulture with the 100-400mm on the Z9. At a 300mm focal length that I wanted for the framing of the bird the eye detect failed. When I went to 400mm the eye detect would work. With the bird sitting still on a branch I was able to use 300mm with manual focus to get the shot I wanted.

 

[jim0379]

#2 is a great image!

Thanks Karen! It was a wonderful way to end a photo afternoon. The drive home made me start thinking about getting a handle on video, as the sound of the impact was so impressive.

 

[MrFotoFool]

I believe they are too far away (too small in the frame) for eye detection to work. They eye has to be bigger for the camera to grab it. I use a Z8 (not a Z9) but I have given up on that mode and now shoot exclusively in spot focus, where I use the four way control to put the focus point where I want it. I found the auto mode (even with eye control) too unreliable when the animals was behind a bush or similar.

 

[jim0379]

I believe they are too far away (too small in the frame) for eye detection to work. They eye has to be bigger for the camera to grab it. I use a Z8 (not a Z9) but I have given up on that mode and now shoot exclusively in spot focus, where I use the four way control to put the focus point where I want it. I found the auto mode (even with eye control) too unreliable when the animals was behind a bush or similar.

I have had the same experience with partially occluded views of the subject, and have a function button programmed to go to spot focus to see through the obstacles. But that didn't apply in this case. The display in the view finder was consistently transitioning from the wide-area with animal detect green box on the BBAF to a white box on the eye which turned green when I held the lens function button to go to 3d tracking. The camera knew where the eyes were. Until they weren't there.

 

[bsinc1962]

I shoot Bighorns quite a bit. (understatement) I turn off animal eye tracking if they're doing anything more than just standing around. I use wide area small by default and let the depth of field take over depending on how far away they are. Fn1 is programmed to single point.

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[bsinc1962]

That first image is great. Having both of them upright is a special moment.

 

[jim0379]

That first image is great. Having both of them upright is a special moment.

Thanks. I think I actually photographed about every other scuffle. They would pace and circle and then go eat some grass. And then start the cycle again, and actually butt heads. I just watched several of them, just to absorb and try to understand the behavior. It was as much like a dance as a fight, because if one didn't feel the moment and respond, the other would unwind a bit and start the escalation cycle over again.