Author Topic: Focusing Troubles  (Read 296 times)

wilheldp

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Focusing Troubles
« on: October 03, 2017, 05:30:38 PM »
I have shot several videos with my camera now, and I'm having a lot of trouble getting the subject in focus.  I am using the focus peaking, and try to get the greatest concentration of cyan dots on my subject, but everything I shoot seems to come up ever-so-slightly out of focus.  I rarely use the kit lens down to F1.2 (shoot mostly in bright sunlight or with Godox + Fresnel directly on subject), so I don't think tiny depth of field is my problem. 

Does anybody have any tips for proper focusing?  I'm assuming this is just a photography problem (I don't have a lot of experience with manually focusing video lenses), but I can't seem to grasp it after 20 or so videos.

Electra

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Re: Focusing Troubles
« Reply #1 on: October 03, 2017, 06:00:10 PM »
Once the option to zoom in returns that will be handy and will make things easier.
Until then, I've found putting a card/piece of paper with some sharp black/white text or lines against the subject, focusing that and then doing the shot works for me. But that isn't always possible.

jasonfish

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Re: Focusing Troubles
« Reply #2 on: October 03, 2017, 06:23:08 PM »
What resolution(s) are we talking about here? Not to say that getting good focus isn't hard (it definitely can be), but I wonder if you're mistaking sensor softness for blurriness.

tesla500

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Re: Focusing Troubles
« Reply #3 on: October 03, 2017, 06:23:31 PM »
What settings are you typically using for aperture when you're having focusing problems?

Sometimes I find it helps to leave the aperture wide while focusing then close it down after, the increased reduced depth of field makes it easier to find focus.
« Last Edit: October 03, 2017, 08:31:32 PM by tesla500 »

John DeLonghi

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Re: Focusing Troubles
« Reply #4 on: October 04, 2017, 03:56:34 AM »
Can you post a video here? I think it's likely you're just seeing some image softness as jefish says.

wilheldp

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Re: Focusing Troubles
« Reply #5 on: October 04, 2017, 01:50:05 PM »
https://youtu.be/CgfhEjWu2As

Here are some shots I took yesterday at various frame rates.  Black Cal has been done on most of those resolutions, and I did a White Balance correction before shooting.

John DeLonghi

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Re: Focusing Troubles
« Reply #6 on: October 05, 2017, 06:39:53 AM »
Difficult to say with that subject matter. You other videos look OK apart from the red colour cast.

Camoit

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Re: Focusing Troubles
« Reply #7 on: October 05, 2017, 05:04:38 PM »
You can always print out a focus target and set the back focus. Mine was off just a touch. Bu that is something I have always checked since I do a lot of CCTV camera set up. They always need to be set since the old cameras did not have a lens.

Johnny

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Re: Focusing Troubles
« Reply #8 on: October 07, 2017, 03:19:21 AM »
Have you tried adjusting backfocus in the camera?
I had to do it for my camera because I have different lenses.

wilheldp

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Re: Focusing Troubles
« Reply #9 on: October 09, 2017, 05:43:20 PM »
Have you tried adjusting backfocus in the camera?
I had to do it for my camera because I have different lenses.

Yes...the backfocus ring was loose when my camera arrived (C-CS mount came completely off when I tried to remove the dust cap).  When I finally figured out what I had done, I followed the backfocus adjustment procedure in the instruction manual. 

I think some of what I'm seeing is softness, and I think some of it might be my inexperience with working with video lenses.  DSLRs with auto-focus lenses have spoiled me.