Video Autofocus with A7Rii - fast moving subjects

[mdavis501]

I am interested in the A7R ii as a video camera for wildlife.  Although most videographers shun autofocus, I think we are evolving into video autofocus and this interests me in that I do not want to be trying to pull focus on fast moving animals or birds in flight.

 

The issue seems to be that the lock on focus modes are only there for the native e-mount lenses and there are no e-mount lenses long enough for most wildlife video. 

 

I was thinking that the sony A-mount 70-400G2 with the LA-Ea3 adapter would be about the best choice to keep as many of the video autofocus functions as possible.  However, can't find anyone who has used this combination for sports or other fast moving subjects.  I understand that the lock on will not work with the A-mount lenses, but was thinking that the autofocus in video would perhaps still be good enough. 

 

Anyone with thoughts or experience with long lenses on the A7Rii and fast moving subjects?

 

 

[Snowfun]

If AF is important to you, I'd suggest that you look at the C300ii... Vastly superior AF (although much more expensive). You won't need to compromise with lenses either.

Not personal experience but from eoshd.com.

On the other hand... Do you really want/need AF for this?

Tim

[tarkane]

Hi,

 

I'd suggest you to watch 

from beginning to end. It's quite informative regarding A7R II's focusing system in general and also there are some sports and BIF (Birds In Flight) examples/tests that are shot/done with LA-EA3 + SAL 70-400mm G II. 

 

Cheers,

 

Tarkan

[mdavis501]

AF for predictable things can be done manually, but it is the unpredicable movement of animals that best benefit from video autofocus.  I can't get the erratic movements of crowned cranes dancing by pulling focus.  At least I can't.  I'm sure there are those that have shot video for a long time and can. It is for sure doable as I can watch the many videos of animals in erratic movement.  So, I'm hoping the A7Rii video will be a workable solution for me.  Thanks.​

[mkg3]

Hopefully Sony introduces FE 300mm+ lens and teleconverter.

 

I've been using SEL 70-200G to video soccer games and AF is very fast and accurate.  Clearly, humans don't move as fast as animals but the actions are much closer than them too.  So in terms of the rate of moving in and out relative to the frame probably isn't too different.

 

There have been several reviews regarding how Canon and Sony long zoom with either Metabones or Sony's A to E adapters but the performance using AF for stills have subpar or inconsistent at best, which would lead me to guess that for video would hunt AF as well; hence, needing a native lens.

 

Maybe in one of the new lens announcement that SAR has been mentioning every week but illusively not announced, will include long end zoom or prime...  I would love to see a 200-400f/4 range (f2.8 will be simply too excessive - both cost and size).

[mdavis501]

Hopefully Sony introduces FE 300mm+ lens and teleconverter.

 

I've been using SEL 70-200G to video soccer games and AF is very fast and accurate. Clearly, humans don't move as fast as animals but the actions are much closer than them too. So in terms of the rate of moving in and out relative to the frame probably isn't too different.

 

There have been several reviews regarding how Canon and Sony long zoom with either Metabones or Sony's A to E adapters but the performance using AF for stills have subpar or inconsistent at best, which would lead me to guess that for video would hunt AF as well; hence, needing a native lens.

 

Maybe in one of the new lens announcement that SAR has been mentioning every week but illusively not announced, will include long end zoom or prime... I would love to see a 200-400f/4 range (f2.8 will be simply too excessive - both cost and size).

Well, maybe the answer is to start with this lens that you are using and wait for something longer. Wildlife at 200mm is simply not long enough usually, but if I shoot apc then I think I get 300mm.

 

Are you happy with the video autofocus?

[Snowfun]

Just speculating here but to what extent does motion blur help hide minor focus issues? I'd prefer some (slightly) out of focus sequences rather than focus hunting. If things are moving unpredictably how will the camera even know what you want to focus on?

I guess too that taking a lot of patiently obtained footage will result in a few seconds of the type you really want/need.

Tim