changing black levels for color shit in timelapse

Started by skippy2008, August 01, 2020, 07:05:37 PM

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skippy2008

Hello guys

First, sorry for my english, it' not my native language. I'll do my best

I have an issue with timelapse sequences that show color shift from frame to frame (going from green to magenta and vice versa). After researching on the web, i found out that it came from my camera that was not recording the same values for the RGB Black levels. The fix for this problem is to extract the metadata from a frame that has the correct tint, note the 3 values for "black level green, blue and red" and then batch processing all the frames of the sequence inputing those "good" values. I've tried to document myself to do so but its a pain in the ass and i really don't understand nothing at command-line application.

Please, is there someone that could help me by giving me the steps to do so ??
- extract metadata from a "good frame"
- input the same black level values for all the frames of the directory

I'm on Facebook groups where lots of people have the same issue than me but no-one find the solution/ I can help all these guys, if you tell me how to do it   lol

Im running on MacOS (with Terminal) but i assume the command must be the same on Windows or Mac ??

Hoping for your help. Thank you very much

StarGeek

I'm assuming these frames are individual files and not part of an existing video?

Do you have a bad and good frame you can share with us so we can take a look?
* Did you read FAQ #3 and use the command listed there?
* Please use the Code button for exiftool code/output.
 
* Please include your OS, Exiftool version, and type of file you're processing (MP4, JPG, etc).

Phil Harvey

What type of images are these, and from what camera model?

If you can see the black levels in ExifTool, then you can likely write them too.  Did you check the ExifTool output to see if they exist in your images?

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux/PowerShell, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

StefanC

Hi guys, other noob here but with the same topic. I am quite desperate because I have very limited understanding to all those commands etc., so I installed also the GUI which is very helpful...but:

ISSUE:
I basically have the same issue - no matter the manual settings applied while shooting a timelapse (that did not change), two shots done seconds apart with NO change in light whatsoever have different tint. Wrong one being more red/magenta than the other. I have found on dpreview forum that a guy with panasonic had this same issue and found a LEVELBLACKRED data that was changing between shots - after normalizing the value, cast flicker was gone. I use Nikon D750 and even though I can see the shift on the monitor, I can see the shift in red values of RGB in Rawdigger app (histogram and also numeric RGB value), I am somehow not able to find out what tag in EXIFTOOL look for. I see only Blac
The issue might be I am looking on converted NEF into DNG files (by lightroom) and they possibly do not consist of those data (which I somehow doubt because Rawdigger is able to see the difference and I believe it is not done from nothing than data inside the file:) ). I don´t have original NEF files, but something is telling me I can recreate this problem in order to get NEF files with this inconsistency.

What am I looking for:
I DON´T WANT IT FOR FREE. I am looking for a person who will help me to:
1. analyze what tag I am looking for.
2. analyze if only NEF can be used or also DNG file
3. provide me a short step by step how to proceed in order to "normalize" those jumping values in the future.
I DON´T WANT IT FOR FREE - yes, I honestly don´t have time to learn complete new skill (maybe there is no help to those inconsistent files), ask here for help and then come back and waste anyone´s time to answer my stupid questions over and over and since many users here are skilled, I will gladly pay for the service (if we are able to find mutual agreement on the price).

Thank you very much in advance, If someone sends me to hell, fair enough, I at least tried it :)
Stefan