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March 7th, 2008, 11:41 PM | #1 |
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Join Date: Feb 2005
Location: San Francisco, CA
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HDX900 Horizontal Banding
I'm getting some odd horizontal banding on a HDX900. It's intermittent, but I can see it in the viewfinder and it lays down to tape. It lasts a few frames, but modulates as it does. I've included an attached frame grab - look in the boy's hairline just below the top of the frame and at the very bottom of the frame on the left. The bands span the entire width.
I'm working on a documentary about urban high school kids and am shooting on the run with the HDX900. I have a sound person tethered to the camera with a breakaway XLR cable. She has a shotgun on a boom and carries one or two wireless mic receivers depending on who we're following. We always have our cellphones off when we shoot (I found long ago that my iPhone causes strange audio interference on cameras and even home stereos). After noticing severe banding in a classroom two days ago, I sent the camera back to Panasonic and received a loaner to continue the shoot. Shooting in the same classroom, with the same kids, with the same audio setup with this loaner camera on the same settings as the original, we saw no banding in the new footage. Panasonic is saying that the camera is fine and that the problem is a wireless mic or a cellphone in close proximity. Have any of you seen this? What do you think is "close proximity"? We're working in a very uncontrolled documentary environment and there's no way we're going to get everybody we encounter on the fly to turn off their cell phones. Any insight would be helpful. Cheers |
March 8th, 2008, 01:09 PM | #2 |
Go Go Godzilla
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The banding is so slight I almost didn't see it. I'm not sure it's an RF issue; assuming you're using a wireless mic system designed for pro-video I'd have a hard time with that explanation and, that would create a different type of visible noise than what I've seen from strong RF noise.
Jim Fast, who is the Panny repair rep in CA has at least one RF expert at his disposal; if you get the camera back and you can replicate the problem I'd have Jim's team take a look at it again. It would be important to know the exact environment surrounding the camera and, exactly what was connected to the camera during these moments when you see the banding. To me, it's almost as if too much current is being drawn from the camera battery due to too many accessories attached at one time - that's what I've seen cause banding in a Varicam, but that was an extreme case and we knew how to fix it. Replicate the problem (if possible) and make notes and send it to Jim. |
March 15th, 2008, 07:18 PM | #4 |
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Banding Continued
Thanks Robert - for your thoughtful reply and your reminder to check back in. I've been in the field, and haven't had time to get back on here.
As I said, the loaner camera exhibited no similar symptoms, and Panasonic has had our original camera for over a week now (I've been communicating with Jim and others there). My producer sent them a master tape and we received a reply that basically said they are puzzled by the problem and not quite sure what's going on. They are thinking of sending the footage to the camera factory to try and figure it out. In the meantime, they're offering us a loaner immediately. We're curious to test all of our batteries (but have no camera body to do so right now). We think that in our shoot with the loaner, one of the six batteries we have went unused. It's possible that it is the culprit if you are right Robert. I'll update this thread when I have new information. Cheers |
March 31st, 2008, 05:10 PM | #5 |
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Problem Found
Turns out I'm not crazy. There was a significant problem in the black levels at low light on this camera. One of the circuit boards was problematic. Panasonic had it for a few weeks, didn't find anything and shipped it back.
After that, A local camera guru in Boulder hooked it up to a waveform and found the problem in 15 minutes. We recorded it, and Panasonic has since fixed the problem... so they say. The unit is being shipped back now. |
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