Thom Hogans’ ‘Hit Rate’ article.

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Good article. I agree I don't give much credence to the idea of hit rate, or even always understand what people mean by the term. I guess I think of how many times the autofocus does what I hope it will do unless there is a good reason it doesn't, like being too far away or too low light.
 
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He is only partly right. When photographing rapidly approach osprey with a D5 my capture rate was roughly 90%, but with the D850 with the battery grip and the same EN-EL18 battery the rate was roughly zero. The D850 could not focus fast enough on the rapidly approaching bird. This is the toughest situation for an autofocus camera and 20 years ago even pro cameras failed to focus accurately on fast approaching runners.

Thom also fails to appreciate, and this is surprising, is that the pro level cameras have different autofocus motors and the ones in a D3/D4/D5 were more powerful than the ones in lower tier cameras. This was noticeable in how well a camera could focus a super telephoto lens on a target.
 
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Paul T said:
People may be interested in Thom Hogans’ article on ‘Hit Rate’. I certainly found it of interest.

It’s Not the Camera That’s the Problem | Thom Hogan

Does the term "hit rate" have any meaning?
www.zsystemuser.com
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Naw, not really. I don't do "scientific tests," I go out and shoot flying birds and running animals in real situations and I know 100% for certain that the AF on my A1 is more accurate than the one on my old Canon 7DII.
 
Calson said:
He is only partly right. When photographing rapidly approach osprey with a D5 my capture rate was roughly 90%, but with the D850 with the battery grip and the same EN-EL18 battery the rate was roughly zero. The D850 could not focus fast enough on the rapidly approaching bird. This is the toughest situation for an autofocus camera and 20 years ago even pro cameras failed to focus accurately on fast approaching runners.

Thom also fails to appreciate, and this is surprising, is that the pro level cameras have different autofocus motors and the ones in a D3/D4/D5 were more powerful than the ones in lower tier cameras. This was noticeable in how well a camera could focus a super telephoto lens on a target.
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I guess this is something that confuses me a little, because in my Canon system, the AF motor is in the lens. For example the RF 100-500 lens has two AF motors that work together. Are you saying Nikon has the AF motor in the camera? I know the old timey ones did, but the Z system?
 
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bleirer said:
I guess this is something that confuses me a little, because in my Canon system, the AF motor is in the lens. For example the RF 100-500 lens has two AF motors that work together. Are you saying Nikon has the AF motor in the camera? I know the old timey ones did, but the Z system?
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To be fair he was referring to the latest flagships, not older cameras or entry models. The R1/R3, Z8/9, A1ii/A1/A9iii cameras.

I tend to agree if you aren't getting a high hit rate with one of those cameras you probably need to learn to work with the AF system a bit more and turn off auto everything/SD and override when needed. They all have issues with SD in certain situations.

The Z8 I know will hit very high with a direct oncoming subject with SD off. I tested it on my DJI Spark (size of a pigeon) coming right at me in sport mode using a GPS flight plan so I could repeat the exact path over and over. 98% consistently in 3D track with SD off. That was out of over 900 shots. It took a while to count and check them all.

So I know that camera can track something coming right at me extremely well. The Zf hit 85% in mechanical and 94% in electronic with the same test run. Mechanical shutter was worse hit rate wise consistantly. Both in 3D Track for that test. Z5 was 72%. D-750 95%. A short buffer hurts the D750 badly.
 
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bleirer said:
I guess this is something that confuses me a little, because in my Canon system, the AF motor is in the lens. For example the RF 100-500 lens has two AF motors that work together. Are you saying Nikon has the AF motor in the camera? I know the old timey ones did, but the Z system?
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Yup, since the 90’s Nikon AF lenses have relied on their own internal AF motor. The flagship DSLRs did have an internal AF motor for legacy AF lens support but none of their mirrorless cameras have an AF motor in the camera body.

There’s been a lot of discussion on possible AF performance differences between the flagship bodies and other cameras possibly linked to battery or AF system differences but none of their mirrorless Z cameras, flagship or otherwise have internal AF motors.
 
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Very good article. Often times I will look at my images in the EVF to make sure that I am getting the kind of image I want and that most of my images are in focus or to make sure that my shutter speed is fast enough. I shoot sports as well as wildlife and I must look at the images to know that I am where I want to be. Like others I don't look at hit rates. If I have non usable images then I take the blame as I know it has to be my error. It may be wrong settings or too slow of a shutter speed.

I have had the opportunity to shoot with enough professional photographers to know that there are skills that the best photographers have. It may be experience or it could be lots and lots of practice or a combination of both. These folks can and will teach you a great deal even in this age of mirrorless cameras and very fast focus. For example, if you have ever sat on the baseline of a D-1 Basketball game, you know that the ref is going to get in the way and mess up your shot. I have taught myself and ability of reaching out with the camera and shooting and action shot around the official. I have been able to catch a player driving to the basket and getting a dunk or and alley oop dunk without putting my eye to the camera or looking through the back screen. I have missed a lot of shots trying to do this but if I were counting hit rates, it would be much higher now with the Z8 or Z9 than it ever was with my D500 or D850. We have students with cameras shooting for the school every game. When they see me taking shots like that they can't believe that I am getting images and before long I see them trying it. Often times I get many shots of players coming right at me with the ball in both football and basketball. Yes it is a tough shot but Ive done it so many times that I have no problems getting the shots I want.

The camera's are getting better and can do things better than ever. However, it is still the person behind the camera that creates the image and the experience and practice the photographer uses is the most important part of the images we take.
 
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The 4" behind the camera matters, as it always has for in flight decisions and reactions. Saying this, the latest Autofocus systems are impressive.

The article fails to mention the primary differences in AF sensor technology, cross-type designs particularly where the Nikon D6 is unique, with its triplet AF sensor design. Thus D6 > D5 > Z9 for snap on speed and resolving very blurry patterns.

However, the latest AF motors inside respective exotic telephotos might be important [eg 400 f2.8S TC (silky swift motors) vs 400 f2.8E FL vs 400 f4.5S] but we await scientifically rigorous tests.

My parochial testing agrees with the industry commentaries and available engineering information. Software AF algorithms have become highly tuned. Otherwise the AF sensor hardware is the main reason why ILCs differ in their abilities to snap on to and stick on to fast moving subjects.
 
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fcotterill said:
the latest AF motors inside respective exotic telephotos might be important [eg 400 f2.8S TC (silky swift motors) vs 400 f2.8E FL vs 400 f4.5S] but we await scientifically rigorous tests.
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Going back to the launch of the Nikon F5, Nikon quoted an example AF tracking ability.
This type of information seems lacking from current camera specifications – possibly because there are so many variables and also because there is no equivalent of a CIPA standard.
 
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