Blackmagic 6k Pro Sensor Problem and LUT Zebra Issue

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rmurthy2

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Blackmagic 6k Pro Sensor Problem and LUT Zebra Issue

PostSun Sep 25, 2022 2:21 am

Was on a shoot when all of a sudden during a few shots, I had this thin purple/green horizontal line that would run down the frame as though it was a scan line. I hadn't changed any settings as far as frame rate or shutter speed go. Included a photo here.

Image

Also, I was wondering if anyone else had the following issue when recording LUT to clip. I noticed the zebra stripes would appear even if the area wasn't overexposed. However, the historgram and the false color map both show that same area where the zebra stripes are present aren't actually overexposed. During a shoot I didn't use false color and second guessed myself with the scopes so I ended up underexposing accidentally by a bit. I had the zebra set to 100%.

Lastly, I have an issue with my touch screen. It becomes unresponsive at times. Especially when I double tap to zoom in. It becomes unresponsive and difficult to get out of. Anyone else having this problem?
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Adam Langdon

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Re: Blackmagic 6k Pro Sensor Problem and LUT Zebra Issue

PostMon Sep 26, 2022 2:35 pm

not sure about the purple line, but the zebras appearing with the LUT applied means that the LUT is spreading the information out (contrast) and THATS what's clipping, meaning that the LUT itself will loose highlight information. (if i understand it correctly)
Ursa Mini 12k +Rawlite - Cinema Camera 6k - SLR Magic APO Microprimes PL/EF - Tamron 24-70mm f2.8 G2 - Aputure Lighting
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rick.lang

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Re: Blackmagic 6k Pro Sensor Problem and LUT Zebra Issue

PostMon Sep 26, 2022 4:48 pm

Is the fuzzy green area and the sharp magenta line appearing in the recording or only the camera monitor?

Odd the green portion almost disappears when the line crosses the head, but is strong on the underexposed background. Still it suggests a sensor/scan related issue. You can’t shoot with that anamoly. If it happens again, I hope your warranty is active as I think it’s going to require an RMA to BMD.
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rmurthy2

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Re: Blackmagic 6k Pro Sensor Problem and LUT Zebra Issue

PostMon Oct 03, 2022 2:33 am

Adam Langdon wrote:not sure about the purple line, but the zebras appearing with the LUT applied means that the LUT is spreading the information out (contrast) and THATS what's clipping, meaning that the LUT itself will loose highlight information. (if i understand it correctly)


So I brought that same clip into Resolve and no part of it is actually overexposed. Again, the histogram and the false color also didn't show that anything was overexposed. But the zebras did and I second guessed myself with the histogram reading and trusted the zebras more so underexposed the footage a bit. So for some reason, when recording LUT to clip the zebras are incorrect. Hopefully a camera update can fix that.

rick.lang wrote:Is the fuzzy green area and the sharp magenta line appearing in the recording or only the camera monitor?

Odd the green portion almost disappears when the line crosses the head, but is strong on the underexposed background. Still it suggests a sensor/scan related issue. You can’t shoot with that anamoly. If it happens again, I hope your warranty is active as I think it’s going to require an RMA to BMD.


It's appearing in the actual recording as I took a screenshot from Resolve. That entire clip is unusable as it has that same line running down the screen as though it's a scan line. It happened again on another shoot that I was on for a few clips so hopefully I can get it RMA'd.
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robert Hart

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Re: Blackmagic 6k Pro Sensor Problem and LUT Zebra Issue

PostTue Oct 04, 2022 7:20 am

The purple line is a bit of a worry. There is a remote possibility there was a pulsating light source like an LED somewhere just out of the shot but getting into the image.

A touch screen losing its touch suggests something may be becoming tired in the camera. However, depending upon your age, some touch screens do not work so well in dry weather. Relics like me have worn fingerprints and tend to have dry fingertips. The AMX videoconference controller at my old workplace would ignore me until I either licked a fingertip (not healthy) or kept a piece of dampened tissue nearby to moisten the digit, then all would be well.

It is probably time to send the camera back to BM for a check and some healing before your warranty runs out.

Slightly offtopic, do you have a third party monitor or other electronic device connected to or operating very near to the camera body?

My personal preference is to trust the histogram and sometimes use the zebras to make me wake up out of my stupor and check the histogram.
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ttakala

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Re: Blackmagic 6k Pro Sensor Problem and LUT Zebra Issue

PostTue Oct 04, 2022 11:54 am

rmurthy2 wrote:Lastly, I have an issue with my touch screen. It becomes unresponsive at times. Especially when I double tap to zoom in. It becomes unresponsive and difficult to get out of. Anyone else having this problem?

The touch screen occasionally becomes unresponsive on my 6K Pro too. It's not about dry fingers, it just happens randomly. I found that the easiest way to refresh it is to go in and out of the menu by pressing the physical menu button twice and it works again. That said, I'm also curious if other people have the same issue, not many responses on this post, at least.

Bigger issue for me has been the ND filters getting stuck, I've sent the camera back twice. After the first service it worked for a couple of days and then the filters got stuck again. And recently I got a video from the service showing that it did indeed work again when they received it. Still waiting to get it back. I saw some advice here on the forums about tapping the camera to dislodge whatever is physically stuck in there, but it didn't help in my case. Though, if it happens again, I should probably pack it in a cardboard box and simulate a trip to the UK service center by kicking it around the house and leave the box sitting on a shelf for a few weeks as if in customs processing. Sounds a bit salty, sorry, had to vent. :x

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