Sony A6600 Focus Hunting

[EchoDeltaMike 0]

Hey,

Just got into the hobby and new setup with a Nauticam A6600, Sony A6600 with a 10-18mm lens. I took it on a test dive today shooting video (4k/30fps) and trying to figure out how to avoid the Sony's focus hunting all the time. The lens I'm using does not have a manual focus gear available for the housing so not sure how to solve this as I would use MF if there was the option.

Sample: https://drive.google.com/file/d/1MQsCmlrhcJzxe7WjOyFRkEKuxJoYP49U/view?usp=sharing

I set the focus to centre instead of wide as I was worried it would start to focus on other objects but the hunting is driving me mad. I'm going to test focusing normally and then using something like Focus Hold mapped to button to lock the focus, but this has it's own issues since if I move or the object does, then I cannot adjust.

Any tips would really help!

TIA

[ChrisRoss 150]

Do you have the option to back button focus?  You would then AF & release the button and start shooting.  I guess you could edit out where you change focus point if that was necessary.

[EchoDeltaMike 0]

Hey Chris,

Yes in fact I was considering that option but once I release, the AF starts hunting to keep focus. I'm also considering mapping Focus Hold or switch to MF after focusing. Problem being, as you swim towards / away from the subject you would lose focus. 

Going to try some more settings tomorrow as hard to test on land since there is less going on versus underwater (fish / bubbles / particles).

Thanks for your help :)

 

 

[ChrisRoss 150]

1 hour ago, EchoDeltaMike said:

Hey Chris,

Yes in fact I was considering that option but once I release, the AF starts hunting to keep focus. I'm also considering mapping Focus Hold or switch to MF after focusing. Problem being, as you swim towards / away from the subject you would lose focus. 

Going to try some more settings tomorrow as hard to test on land since there is less going on versus underwater (fish / bubbles / particles).

Thanks for your help

 

 

Back button is the solution , there's a different setting somewhere to change it so the shutter button no longer activates AF, you should be able to google it to see where it is done in the menus.

[EchoDeltaMike 0]

Thanks, will give it a try!

[Captain Fathom 8]

I have the NA-6400. I have not noticed AF hunting but regardless please set up the back button focus. It is a learning curve but it is also a game changer. You can prefocus on something and wait for your subject to enter the preset focus zone or focus before shooting but with BBF, when you push the shutter trigger and the camera goes click, focused or not. No wait. Set to single shot to start with and also turn off AF tracking. It seems my camera, if I keep the BBF engaged (pressed) the focus tracks, when I release the BBF it locks there until I focus yet again or the power is cycled (and possibly sleep).

[Davide DB 312]

I don't have Sony but the option is definitely there. You just have to look in the menus. Usually the AF-Lock feature has numerous settings. Also you have to disable AF on the shutter release. That said in video you should try to work in hyperfocal or near hyperfocal, so with apertures tight enough to have a comfortable depth of field. Of course, it's impossible to approach a subject from 10 feet and keep it in focus to within a few inches. You work on editing with different shots.
It might be different with a machine equipped with DPAF, in which case you could work in continuous autofocus. Never tried.

PS
To get an idea of depth of field you can use one of the many online calculators.

https://www.photopills.com/calculators/dof

 

[gobiodon 56]

Do you have the proper dome port for this lens?

 

[EchoDeltaMike 0]

Yes I do and I’m using the 10-18mm lens.