Author Topic: One line of lighter pixels in saved video.  (Read 4718 times)

NoDak

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One line of lighter pixels in saved video.
« on: September 26, 2020, 08:47:25 PM »
Had video today have one line of pixels lighter than the rest. Any idea the cause? Running the new OS. Line was not visible when reviewing the footage before saving.





Sometimes looks to be the same line.



Sometimes it's a different line.



Sometimes it disappears completely.



Video I took yesterday did not have this problem.



I noticed today that sometimes during saves the FPS that it was saving at would drop for a few seconds before resuming. not sure if that is normal behavior or a sign of trouble.

Thanks for any help you can give.

Bian

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Re: One line of lighter pixels in saved video.
« Reply #1 on: September 26, 2020, 10:04:46 PM »
At my cameras this thin line happend if I change the resolution and forgot a black calibration. Or I using the exposure slider - then I have to make a black calibration too.
« Last Edit: September 26, 2020, 10:07:18 PM by Bian »

NoDak

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Re: One line of lighter pixels in saved video.
« Reply #2 on: September 26, 2020, 10:20:32 PM »
At my cameras this thin line happend if I change the resolution and forgot a black calibration. Or I using the exposure slider - then I have to make a black calibration too.
Waaaaaaait. So using the exposure slider requires a black calibration afterwards?  :o Was this documented somewhere and I just completely missed it or forgot it?

NiNeff

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Re: One line of lighter pixels in saved video.
« Reply #3 on: September 27, 2020, 03:20:42 AM »
At my cameras this thin line happend if I change the resolution and forgot a black calibration. Or I using the exposure slider - then I have to make a black calibration too.
Waaaaaaait. So using the exposure slider requires a black calibration afterwards?  :o Was this documented somewhere and I just completely missed it or forgot it?
I had this problem as well in the early days, so there's probably a threat about it here somewhere, but it's not exactly in the official documentation ;)

Martin

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Re: One line of lighter pixels in saved video.
« Reply #4 on: September 27, 2020, 05:17:27 AM »


Sometimes it disappears completely.

It's still there though:


When in doubt: calibrate black once more :)

Regards
Martin
« Last Edit: September 27, 2020, 05:19:30 AM by Martin »

Photopage

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Re: One line of lighter pixels in saved video.
« Reply #5 on: September 27, 2020, 02:28:39 PM »
I now do lots of Black calibrations when Iím working.  As the camera starts up and slowly gets hotter I Black Cal for every take.  Once the camera is running at a constant temp I do a calibration about once an hour.  Any change of Shutter angle / shutter speed needs a new Black Cal, and any other changes like FPS and sensor size, black cal.

I dont like the exposure slider.  Itís way too easy to change the shutter settings, and looks the same as the playback slider, which I use all the time.  Iíve accidentally changed the shutter dozens of times by mistake.

Hope your line is fixed now?

Martin

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Re: One line of lighter pixels in saved video.
« Reply #6 on: September 28, 2020, 08:36:42 AM »
Black calibration is sooo much faster, now, than it was 3 years ago.
There's no reason to skip those to make sure the camera produces a proper image.

tesla500

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Re: One line of lighter pixels in saved video.
« Reply #7 on: September 29, 2020, 03:49:05 PM »
Waaaaaaait. So using the exposure slider requires a black calibration afterwards?  :o Was this documented somewhere and I just completely missed it or forgot it?

Yes, that's correct, it is listed in the manual but it's easy to miss. On page 9:

Quote from: Chronos_1.4_User_Manual
Black calibration is unique for each resolution, gain setting, and shutter speed. ie. a black calibration done at 1280x1024 with 0dB gain does not apply to 1280x1024 with 6dB gain.

For best image quality, perform a black calibration after changing the resolution, frame rate or shutter speed.

This hopefully won't be required once horizontal black bar calibration is available, this is currently being worked on. Once implemented, every line will effectively have their own black cal performed every frame based on masked-off black pixels on the sides of the image sensor.