Taperssection.com

Gear / Technical Help => Photo / Video Recording => Topic started by: vwmule on March 29, 2017, 05:09:30 PM

Title: iPhone video and focus
Post by: vwmule on March 29, 2017, 05:09:30 PM
I regularly mount my iPhone at a club in D.C. and while the sound is good, I've noticed that the focus goes in an out even after I've locked onto an area on stage. So the resulting video pops in and out of focus. Not horribly, but enough. I suspect it's sound-pressure related as the steady moments are quite clear.

I'd appreciate any tips.


https://youtu.be/BJuD8I-3xBg
Title: Re: iPhone video and focus
Post by: willndmb on March 29, 2017, 06:47:56 PM
Do you have a time where it does it, I skimmed it but didn't see anything

I suspect the lights are hitting it at the right angle and throwing it off
Title: Re: iPhone video and focus
Post by: Fatah Ruark (aka MIKE B) on March 29, 2017, 07:15:08 PM
I'm not a concert video expert, but I've read before that you need to have the camera set to manual focus or this will happen.

I just checked my phone (Nexus 6P) and I don't see any option for manual focus. No idea on the iPhone if that's an option.

Maybe if the stock camera app doesn't have manual focus, some other camera app might offer it.
Title: Re: iPhone video and focus
Post by: vwmule on March 29, 2017, 07:59:39 PM
> Do you have a time where it does it, I skimmed it but didn't see anything

See 30 second to 1 minute mark, for example.

Title: Re: iPhone video and focus
Post by: willndmb on March 29, 2017, 08:57:07 PM
> Do you have a time where it does it, I skimmed it but didn't see anything

See 30 second to 1 minute mark, for example.
im not seeing it, but I'm on a small screen right now too
Title: Re: iPhone video and focus
Post by: morst on March 29, 2017, 09:36:26 PM
I could not look at two songs in a row, it makes me feel woozy.

I suspect it's the image stabilization acting on the moving lights.

could also be related to auto focus on the "tripod" mounted camera.

I'm not a concert video expert, but I've read before that you need to have the camera set to manual focus or this will happen.

I just checked my phone (Nexus 6P) and I don't see any option for manual focus. No idea on the iPhone if that's an option.

Maybe if the stock camera app doesn't have manual focus, some other camera app might offer it.

iphone lacks manual focus on the camera app. Good idea to look for a different app...
Title: Re: iPhone video and focus
Post by: vwmule on March 29, 2017, 11:15:51 PM
Thanks all for checking it out. I think I'll remove that video as it bug shit out of me, too. Will seek another app to shoot video. In general I think the video and audio quality is not bad on the iphone 6.
Title: Re: iPhone video and focus
Post by: morst on March 30, 2017, 12:34:35 AM
I watched at 720 on a big monitor, like 25". Maybe it's ok smaller but .. yeah, I appreciate the effort!!!!
Title: Re: iPhone video and focus
Post by: Gutbucket on March 30, 2017, 09:01:56 AM
At first I was looking for lights-related stabilization issues.  Then I realized it seems to happen only when they are playing, but not during the between song stage banter, even in sections while the lights remain unchanged during those transitions.  I suspect image stabilization being confused by SPL related vibration.  I'm not an Iphone user, does it allow you to switch image stabilization off?
Title: Re: iPhone video and focus
Post by: vwmule on March 30, 2017, 04:49:54 PM
I downloaded FiLMiC Pro, $15 app, and it seems to be very advanced, including allowing image stabilization to be turned off, which I don't think the standard Apple camera app allows. Will give it a spin.

http://www.filmicpro.com/apps/apple/filmic-pro/
Title: Re: iPhone video and focus
Post by: vwmule on May 01, 2017, 05:06:13 PM
An update: Used phone to record at a different venue and the wobbly focus issue was nonexistent. So it has to do with the particular lights at the venue. I haven't yet tried the new photo app I downloaded.
Title: Re: iPhone video and focus
Post by: willndmb on May 01, 2017, 10:55:20 PM
An update: Used phone to record at a different venue and the wobbly focus issue was nonexistent. So it has to do with the particular lights at the venue. I haven't yet tried the new photo app I downloaded.
could be the floor too
I had a lot of similar blur/shake issues recently at a venue were the floor was wood and people dancing shock the hell out of my tripod
Title: Re: iPhone video and focus
Post by: vwmule on May 02, 2017, 03:43:14 PM
In this case, I can rule out floor. Camera mounted to a heavy steel beam.
Title: Re: iPhone video and focus
Post by: justink on May 06, 2017, 08:23:02 PM
it's the software in the phone's stabilization triggered by the minute movement caused by the SPL's of the relative closeness to the subs/stack. 

you'd need to put that phone in a vice on that beam to prevent that.  and even then... the vibration in the beam might still make it happen.  i don't think you can turn off the auto stabilization. 

looks good otherwise.
Title: Re: iPhone video and focus
Post by: taynos on June 28, 2017, 03:10:20 AM
If the focus issues are being caused by lighting changes then you can set the iPhone AE/AF (auto-exposure / auto-focus) to locked by holding down on the screen (while shooting video in the iOS camera - third party apps will have different gesture functionality)  for a couple seconds then the focus will lock and you can focus on the stage and it wont compensate for exposure changes or changes in distance from the subject. You can also swipe left or right (or up or down if shooting profile) to manually change the exposure when in that setting as well.