R6 Mk ll - Odd night sky image problem

[justadude]

I have a question on some night sky images I have been taking with the R6 Mk ll.  I should mention first that I am not new to night sky photography.  I've been doing it since pre-digital days.  I've also shot a lot of night sky images with 4 different Pentax DSLRs, 3 different Canon DSLRs, and now 3 different Canon Mirrorless bodies.  The R6 Mk ll is the first camera I've experienced the following with.

If you look at the two attached images, one is nice and clear, the other seems to have a bit of a rotation to the whole image.  I've only shot night sky images a few times with this camera.  Last month I saw about 10% of my images had this weird rotation.  I wrote it off as shifting sand around the tripod.  Last night I was out taking about 100 shots.  Very sporadic, but roughly half of them look like this.  This last one was taken in the parking lot (solid ground - no shifting sand).

Few notes:
* Camera set to Manual mode
* IS turned off in camera
* The tripod is solid, tight connections on legs and ball head, and far from being underrated for this gear weight.  
* I've used two different lenses where this is happening.  Rokinon 14mm F/2.8 EF mount... Venus Optics Laowa 15mm F/2 RF mount.  Both of these lenses are full manual - no auto setting, so the camera is set to shoot without a lens.

Am I missing something in the settings that is new to this specific camera?  I've never had this happen on any other camera.  Also, I only see this in night sky shots, when on a tripod.  Day shots, on a tripod are never a problem.

[justadude]

I think I may have to do exactly this.  I was hoping that after the previous 5 canon DSLR/Mirrorless models I've owned, they simply added some feature that I missed.  Thank you, John!

[Tronhard]

FWIW, I have the R6II, and just checked on the EXIF data, both using the properties of the file from Windows 11 File Manager, and Adobe Photoshop File Data:

    

[justadude]

I took the Photoshop file info one step further because I had almost exactly the same info as your screenshot, so I went to the RAW Data option further down the list.  It has a lot more of the camera info, but nothing on IBIS.  I don't have Windows, I have a Mac, and I'm a bit surprised there is even less info.  

[johnrmoyer]

I suggest exiftool for viewing metadata. It runs as a command line program on macOS or Linux. Since I have retired and no longer have an employer to require Windows, I do not do Windows but long ago I used exiftool on Windows.

https://exiftool.org/ 

For example:

exiftool -s -G0:2 /Volumes/jrm/photos/2021Jun24/IMG_1931.CR3 | less
# next view only image stabilization
exiftool -s -G0:2 -ImageStabilization -a /Volumes/EOS_DIGITAL/DCIM/100CANON/IMG_0648.CR3
[MakerNotes:Camera] ImageStabilization          : On (2)
[MakerNotes:Camera] ImageStabilization          : On (2)

The less program is included with macOS or Linux and is a pager for viewing text files.

For viewing IS on or off, the second command line lists both instances because I included "-a" on the command line. Usually when there are duplicate tags, they will have the same value.

Another program for viewing exif and other metadata is exiv2 which is built into rawtherapee and gimp. https://exiv2.org/ but I prefer exiftool.

Today, I put my old Minolta film camera lens on my EOS R5. I made 4 images with various IBIS settings. "exiftool -s -G0:2 -a -U -w out3/%f_%e.txt IMG_064[5-8].CR3" command line created a directory (folder) named "out" and placed 4 text files containing the metadata with the defined tag names plus "-U" caused the undefined tag names to be dumped as well. I used the diff program (comes with macOS or Linux) to compare the files. "diff out3/IMG_0646_CR3.txt out3/IMG_0647_CR3.txt | less"

I did not find any differences that I might attribute to the IBIS settings that I changed guessing that as is sometimes the case, the menu choices are represented as integers from zero to last choice. My first guess is that the camera menu choices for IBIS are not recorded in the CR3 file, but it is possible that I just did not find them. The "-ImageStabilization" tag reports IS on or IS off for some lenses and might report IS mode 1, 2, or 3. Except for the tag names that are part of a standard such as EXIF, XMP, or IPTC, the tag names were chosen by the program maintainer to represent what information the tag appears to contain.

The "MakerNotes" tags are specific to the camera manufacturer and are not part of a standard.

The Metadata Working Group is trying to standardize more tags. https://exiftool.org/TagNames/MWG.html

[sutleyar]

Having read most of the responses, I would speculate that the sensor is not quite mounted solidly. (It doesn't take much). When the shutter releases (if your using mechanical shutter) it may be causing the sensor to shift. This is wild speculation, but you've eliminated just about anything else. Are you getting the same results when shooting daytime images? 

[justadude]

All of my daytime images are fine.  I've shot around 1,000 daytime images while we were on vacation, which was after the first time this happened at night, and before this latest time.  All hand held... which points back to the tripod again.  However, the tripod is solid.  I set it up again yesterday just because I'm famous for overkill on checking things.  It takes a good thump to take a photo showing vibration.  I don't mean a big hit... but what I mean is a lot harder than hitting the shutter button than I normally do (I have a light touch in general), and only if I turn the 2 second delay off.  So... it points back to the camera again.  

[johnrmoyer]

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@justadude wrote:

All of my daytime images are fine.  I've shot around 1,000 daytime images while we were on vacation, which was after the first time this happened at night, and before this latest time.  All hand held... which points back to the tripod again.  However, the tripod is solid.  I set it up again yesterday just because I'm famous for overkill on checking things.  It takes a good thump to take a photo showing vibration.  I don't mean a big hit... but what I mean is a lot harder than hitting the shutter button than I normally do (I have a light touch in general), and only if I turn the 2 second delay off.  So... it points back to the camera again.  

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If using  a lens with no electronics, I suggest trying it with IBIS enabled and the focal length for IBIS set in the camera menu.

I expect that a lens with no electronics is the least tested part of the firmware. I guess there might have been more testing done with IBIS enabled than disabled.

The most recent version of exiftool will report pitchangle and rollangle for some cameras. If that works for your camera, it will tell you whether the camera moved. It only works for EOS R5 with firmware versions 1.5 or later.

[justadude]

For anyone following this thread, a minor update... I've been emailing back and forth Canon Tech Support.  They agree from the various photos I've sent that it is not a lens problem, or a tripod problem.  Currently waiting to hear back on a few IBIS questions.  Hoping to get it resolved without sending this in for warranty work since this is my busiest time of the year with this camera.  

Stay tuned.