Focus techniques for video

Hi everyone

I have decided to write a new post on my blog regarding focus techniques in video. I have realised many people struggle with that and there is a lot of blurred footage out there where it does not need to be.

If you want to give me examples or questions I am very happy to take them either here on my blog. Examples are even more welcome.

Thank you

I'm interested. When are you going to make your first post and what platform?

I run my own platform on wordpress http://interceptor121.com since 2013 I think

Great topic. I recently switched to the GH5 with a 14 - 42 f3.5-5.6 II ASPH lens in a Nauticam housing and am trying to figure out focus controls.

1. In MF setting, I cannot find a way to turn the focus ring. I have not been able to find a port with a manual focus gear for the lens. How is manual focus done for the GH5 with 14-42 lens?

2. In MF mode, one is supposed to be able to press the AF/AE button to force the camera to autofocus according to the following GH5 Q and A video https://www.youtube.com/watch?v=wF7zmBnVEWE

I have pressing the AF/AE button whilst in MF mode but I cannot get my camera to focus. On my camera, the AF/AE button (set to AF only) will only cause the camera to focus when in AFC mode.

Thanks

https://studio.youtube.com/video/gWULjjPuDbQ/edit

In the video above, shot with a GH5 and 14-42 lens in AFC mode, there is a manta swimming directly towards me. The camera goes focus hunting a number of times. What settings can I employ to minimise focus hunting?

Thanks

https://studio.youtube.com/video/gWULjjPuDbQ/edit
 
In the video above, shot with a GH5 and 14-42 lens in AFC mode, there is a manta swimming directly towards me. The camera goes focus hunting a number of times. What settings can I employ to minimise focus hunting?
 
Thanks

Int,

I use a Sony AX700 and recently experienced a huge improvement in autofocus success underwater. A diver heard me complaining about focus failure using WIDE, and suggested I try CENTER focus. Oh, what a complete difference it has made!

Here's a bit of detail:

Including CENTER, there are five focus modes available for the AX700 camera in video mode. The other four are MANUAL, ZONE, FLEXIBLE SPOT and WIDE.

ZONE and FLEXIBLE SPOT are available if the screen can be touched or if the joystick can be operated to indicate to the camera where to focus underwater. These aren't available on the Gates housing.

So until recently I used WIDE, following the recommendation of the "experts." This resulted, as you mentioned, in lots of focus hunting and failures to focus. Very frustrating.

When I switched to CENTER focus, magic seemed to happen! Most of the out of focus moments went away - my footage is in focus probably well over 90% of the time. What a great relief!

Hope this helps,

Tom

10 hours ago, wydeangle said:

The GH5 has the equivalent of 'Center'. I am currently experimenting a diamond shaped custom focus area shown on the bottom left in the link.

https://www.youtube.com/watch?v=VYTN56FPq4E

 

  

 

On 1/27/2020 at 3:47 AM, WK's Gone Diving said:

https://studio.youtube.com/video/gWULjjPuDbQ/edit

 

In the video above, shot with a GH5 and 14-42 lens in AFC mode, there is a manta swimming directly towards me. The camera goes focus hunting a number of times. What settings can I employ to minimise focus hunting?

 

Thanks

Can't open this clip?

16 hours ago, Interceptor121 said:

Can't open this clip?

https://www.youtube.com/watch?v=gWULjjPuDbQ

try this one

44 minutes ago, WK's Gone Diving said:

https://www.youtube.com/watch?v=gWULjjPuDbQ

 

try this one

Works

This is a really good example

23 hours ago, Interceptor121 said:

Works

 

This is a really good example

For the manta clip, I was on aperture priority and, if I recall correctly, aperture was set to f7.1 whilst shooting at 14mm. If I were to focus at 2m, everything from about 1m to infinity should have been in focus because of the depth of field. Perhaps I should just lock the focus at about 2m on aperture of f7.1 for my general wide angle shots.

37 minutes ago, WK's Gone Diving said:

For the manta clip, I was on aperture priority and, if I recall correctly, aperture was set to f7.1 whilst shooting at 14mm. If I were to focus at 2m, everything from about 1m to infinity should have been in focus because of the depth of field. Perhaps I should just lock the focus at about 2m on aperture of f7.1 for my general wide angle shots.

Was this with flat or dome port and with or without wet lenses?

Just now, Interceptor121 said:

Was this with flat or dome port and with or without wet lenses?

Flat port. I did not have my dome with me on that trip.

Here is the first part thanks to those who sent clips in

https://interceptor121.com/2020/02/09/focussing-techniques-for-video-part-i-problem-diagnostic/

The topic is waste in this one I talk about issue and fixing it the theory will come in the next two posts together with real how tos