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Old 08-23-2020, 10:48 AM   #1720
sexobon
I love it when a plan comes together.
 
Join Date: Oct 2009
Posts: 9,793
There are internet discussions about this. Seems it's likely to be a byproduct of camera sensors. NOTE: The quote's second enclosed link doesn't work. END NOTE.

Quote:
What causes this weird grid pattern in my picture?


... I found this problem fascinating enough to research a suitable answer.

1) This is NOT Moire interference; as was mentioned above, the grid is far too regular (in both vertical and horizontal direction.

2) This is also NOT noise banding resulting from working the sensor too hard. The banding, again, is far too regular and nothing in the image suggests an unusual exposure which, in fact, looks pretty typical.

3) Some internet sleuthing suggests that this " Grid Banding" processing artifact plagues a few generations of Canon CMOS sensors, going as far back as 2008 and the 5D Mark II (see this link for a cursory description: https://blog.kareldonk.com/canon-eos...rely-worth-it/. According to several users, this grid banding shows up in relatively underexposed parts of an image at fairly low ISO (like the OP's image) and is even worse when recording video.

This link (http://www.dvxuser.com/V6/archive/in.../t-207542.html) describes a 7D users experience with this problem and what Canon did to repair this "unbalanced A/D channels" issue....at least partially. Apparently, there is no "user error" in creating this artifact, it is a known issue with Canon CMOS sensors, and may be repairable by Canon, or at least partially mitigated.
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