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A9 Autofocus and tracking - 2


royprasad
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Second of two remarkable examples of how well the Sony A9 can track a small subject even through distracting or confusing backgrounds. Both shot with a Sony FE 70-300mm lens (I don't have the new 100-400 yet).

 

To see this properly, a file size of ~10 MB would be ideal. I had to compress it to under 1MB, per the site requirements, so I have no idea how well it can be seen.

 

Bottom line: after previously owning a Nikon D3S, Nikon D4 and Canon 1DX II over the years, I have never seen autofocusing and tracking as good as in the A9.

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The only object I see changing position changed very little 

and with a moderate dose of DoF this would require very 

little AF tracking ability, plus the background remains fairly 

constant, which helps any AF system to maintain constant 

recognition of its subject. Additionally, nailing 16 frames in 

a brief burst avoids confusing the AF. IOW, nothing I see 

here tells me about remarkable AF tracking, and the lack 

of resolution is a non-issue in this case.   

  

I do see decent detail in the fluting on 3 utility poles, which 

from nearest to furthest is a distance same as the distance 

traveled by the bus. So the bus is moving within the range 

of sharpness delivered by DoF alone. Probably the AF is 

helping optimize focus, but this is not a really challenging 

situation to demo AF tracking. 

  

This is not to doubt the ability of the AF system, it's just to 

say that there's no data here about it. 

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  • 3 weeks later...

The only object I see changing position changed very little 

and with a moderate dose of DoF this would require very 

little AF tracking ability, plus the background remains fairly 

constant, which helps any AF system to maintain constant 

recognition of its subject. Additionally, nailing 16 frames in 

a brief burst avoids confusing the AF. IOW, nothing I see 

here tells me about remarkable AF tracking, and the lack 

of resolution is a non-issue in this case.   

  

I do see decent detail in the fluting on 3 utility poles, which 

from nearest to furthest is a distance same as the distance 

traveled by the bus. So the bus is moving within the range 

of sharpness delivered by DoF alone. Probably the AF is 

helping optimize focus, but this is not a really challenging 

situation to demo AF tracking. 

  

This is not to doubt the ability of the AF system, it's just to 

say that there's no data here about it. 

 

Did you see the bird?

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Did you see the bird?

   

Thanks for the heads-up. I found it now that 

you mention it. Same deal tho. Proof of zero. 

   

I'm sure the camera does more or less what 

Sony claims it will do ... when conditions are 

favorable. I'm not doubting that. But the bird 

pix neither demonstrate nor deny anything. 

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Thanks for the heads-up. I found it now that 

you mention it. Same deal tho. Proof of zero. 

   

I'm sure the camera does more or less what 

Sony claims it will do ... when conditions are 

favorable. I'm not doubting that. But the bird 

pix neither demonstrate nor deny anything. 

The camera was tracking a moving object in an environment filled with various distracting lights and objects, zero proof?  Surely You're Joking, Mr. Feynman!

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