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Panasonic LUMIX G / GF / GH / GX Series
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Old February 12th, 2011, 02:09 PM   #1
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Auto Focus woes

Am I the only one who doesn't like giving focus sovereignty to a tiny Panasonic computer? I'm a long way from mastering it, but seeing those two floating red squares roaming all over the LCD like a Heads Up Display on an F-16 makes me feel like I have no control. Is manual focusing THAT much of a headache? Well actually it is with the stopless fly by wire m43 glass. But with my 30 year old 50mm SMC 1.4, focusing couldn't be easier, and I have control.

Now, about this facial recognition menu item? I get an anxiety attack just writing the words.
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Old February 13th, 2011, 11:32 PM   #2
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Experimented today with the facial recognition mode. Worked amazingly well on an indoor low light shoot, even on a cat! Glasses, especially sunglasses, confuse it. Maybe a brighter setting would be different. Once I have a chance to edit the footage, I'll decide if it's working well enough for continued use.
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Old February 14th, 2011, 09:38 AM   #3
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Thanks for the input William. Please let us know the camera settings that you used.
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Old February 15th, 2011, 06:45 AM   #4
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14/140 Panasonic lens - 24L - shutter at 50 or 40 - ISO 2800 - F4 - Manual everything except the focus. I was shooting hand-held using an old Spiderbrace.

A curious problem was when I zoomed into a specific person's face who was wearing thick rim glasses. The camera's facial recognition had no problem when the face was less than 15% of the frame but when I would zoom in the camera would loose focus and default to the background. This did not happen with subjects not wearing glasses. It seemed that the software was confused by the eye glass frames. Another subject was wearing sunglasses and a rather fanciful combination of scarves and hats. The facial recognition did not even acknowledge that a face was there but interestingly the subject was in focus in the LCD. I will not review the footage for a few days so I am not sure.
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Old February 15th, 2011, 01:46 PM   #5
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Hi william, that is exactly the kind of thing that worries me about relying on a tiny chip to do what we normally do. I filmed a lecture a few weeks ago with a vintage prime. It looked great, dead on focus. Perfect. Filmed the s oluame lecturer last week and used my all everything m43 and there was far too much focus hunting. To salvage the footage I have all these inappropriate cutaways to lecturer's feet and hand and used a lot of audience cutaways. A one hour edit turned into an all weekend. Edit and finished product kinda sucks.
Are people really relying on auto focus for mission critical work?
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Old February 15th, 2011, 05:20 PM   #6
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Quote:
Originally Posted by William Hohauser View Post
even on a cat! Glasses, especially sunglasses, confuse it.
Is your cat wearing sun glasses..? :)))
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Old February 15th, 2011, 10:03 PM   #7
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You're scaring me Brian. My first shoot with it is Saturday. Oh goody.
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Old February 15th, 2011, 10:19 PM   #8
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It's not a good idea to use continuous auto focus on a fixed subject.
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Old February 15th, 2011, 10:40 PM   #9
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Jim, that makes sense in light of some videos I've seen where the focus changes constantly as people move slighty in a frame. How about the follow focus thingy? You tried it?
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Old February 15th, 2011, 10:56 PM   #10
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I tried it wirh a friend walking across a parking lot and it worked fine but I haven't tested it under varied conditions yet.
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Old February 16th, 2011, 12:35 PM   #11
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There are details to the focus software that I haven't had enough experience with yet. Certainly for a fixed subject I would not use continuous focus. Would need a decent focal chart to make sure that the subject's natural wiggling will not throw them out of the focal plane. The circumstance I was in required a lot of shifting around for interesting shots.

The facial recognition works like I described in low light conditions. Still not sure if low light causes more focal misses or if it reacts faster with a faster shutter. Both of these issues can be encountered with video cameras.

The cat wearing sunglasses was a cool fashion cat but the real cat was wearing contacts.
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