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Canon 7D problems with video focus

Canon 7D Video focus underwater

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#1 Pink Tank Scuba

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Posted 16 March 2018 - 04:18 PM

I'm struggling with video focus on the Canon 7D which will be make or break for me keeping or selling it off. 

I shot this video of a calamari squid hunting yesterday: 

 

As you can see, whenever the squid moves closer to the camera, the footage goes out of focus.

 

I switch regularly back and forward between video and stills, mainly filming marine animal behaviours which can be unpredictable. 

Are there any not-overly complicated solutions to this or is my 7D about to have a 'For Sale' sticker put on it?

 

Thank you in advance for your advice.



#2 sunnyboy010101

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Posted 16 March 2018 - 05:47 PM

Short answer. No. The Canon 7D (I'm assuming you mean the Mark 1 as you didn't specify) does not have continuous autofocus in video mode.

 

Now a lot will depend on your aperature and lens, as depth of field is rather critical when taking video. But... if you like macro like me (60mm lens), then you don't have much choice, IMO...

 

You can press the autofocus button while taking video, but then you get the horrible "hunt back and forth for focus" out-of-focus stuff that can last quite a few seconds. ON video it seems like forever.

 

The only other alternative is to buy the focus gear for your lens and manually focus (and adjust to keep focus) while taking video.

 

In the end, while I really love my Canon 7D for underwater stills (macro with the 60mm lens), I had to give up on video. More video time out of focus than in.



#3 Bevanj

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Posted 16 March 2018 - 09:14 PM

Yep... to get continuous autofocus on any Canon for video, you need a body with dual pixel autofocus - like the 70d, 7dII, 5dIV etc. The 7d sadly does not fall into this category. 

Get some grunty lights, stop it down a touch to increase your depth of field, and bump the iso to compensate, and it will make keeping things in focus easier than if you shoot with your aperture wide open. 

That said, it's far easier to keep things in focus with a wide angle compared with a macro, as sunnyboy010101 is getting at. 

Bevan 



#4 Pink Tank Scuba

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Posted 16 March 2018 - 11:16 PM

Short answer. No. The Canon 7D (I'm assuming you mean the Mark 1 as you didn't specify) does not have continuous autofocus in video mode.

 

Now a lot will depend on your aperature and lens, as depth of field is rather critical when taking video. But... if you like macro like me (60mm lens), then you don't have much choice, IMO...

 

You can press the autofocus button while taking video, but then you get the horrible "hunt back and forth for focus" out-of-focus stuff that can last quite a few seconds. ON video it seems like forever.

 

The only other alternative is to buy the focus gear for your lens and manually focus (and adjust to keep focus) while taking video.

 

In the end, while I really love my Canon 7D for underwater stills (macro with the 60mm lens), I had to give up on video. More video time out of focus than in.

I was scared you might say something like that - who has time for that when an octopus is doing a cartwheel in front of you? :-( Thanks so much for the feedback ...


Yep... to get continuous autofocus on any Canon for video, you need a body with dual pixel autofocus - like the 70d, 7dII, 5dIV etc. The 7d sadly does not fall into this category. 

Get some grunty lights, stop it down a touch to increase your depth of field, and bump the iso to compensate, and it will make keeping things in focus easier than if you shoot with your aperture wide open. 

That said, it's far easier to keep things in focus with a wide angle compared with a macro, as sunnyboy010101 is getting at. 

Bevan 

Thank you for the feedback - honestly, I don't want a logistical nightmare every time something exciting happens underwater that just needs an instant 'Hit and Record' - so sad as the video quality is pretty nice ... when it's actually focussed :-( 



#5 sunnyboy010101

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Posted 17 March 2018 - 09:09 AM

Yea, even with super bright video light and fully stopped down lens, the 60mm macro lens has only a few mm depth of focus. It's OK for critters that don't move much or are really small, but trying to get video of a pacific octo in it's den was just an exercise in mostly-out-of-focus frustration.

 

Now I just stick a 4K go-pro clone on top of the housing's macro port and let it do the video. :-D







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