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]

The Rokinon is an EF mount, and I have used it often for night sky photography on the following... 60D, 80D, 6D, RP and now R6 Mk ll.  Never had any problem with the other cameras.  All hand held daytime images with this lens are fine on all of the above cameras.  I think we can rule out this lens (and besides, I sold it when I bought the Laowa 2 weeks ago, so I can't test further).  

The Laowa is new, I have only used it on this camera and the R8 (which is converted to infrared, so I use it during the day).  Hand held daytime shots with both the R8 and R6 Mk ll are fine with this lens.  

I am going to set up tomorrow with a strong ND filter and do some daytime long exposures on a tripod to see if I can get the same weird effect.  I will also try with the R8 on a tripod to see what happens.  However, since both of these lenses do not have any electronic communication with the camera (both are full manual), and since the movement/rotation/pattern is identical, I really do not think it could be the lenses.

Additional notes...  I've used the R6 Mk ll three times now for night sky photography (Milky Way, and/or aurora).  

The first time was with the Rokinon EF lens back in April.  Did not experience this problem at all.  

Second time was in May.  Again with the Rokinon.  Maybe 100ish images, roughly 10% had this effect. Same tripod, same location, same conditions, same settings.

Third time was last night.  Only difference was the switch to the Laowa, but other than that same tripod, same location, same conditions, same settings.  Roughly half of the images had this effect.

[justadude]

One more item.  This photo was taken facing the same direction as the bad photo, but 5 minutes earlier, before walking up to the parking lot.  Same exact exposure time and all other settings.  Look at the trees - no movement from wind, which shows the other image wasn't wind on the trees, but this weird camera movement.  This image SHOULD have been shakier being I was set up on soft sand, but you can see how clear it is.  

[stevet1]

Gary,

If you take the "bad" photo that you provided, and blow it up quite a bit, you will see some kind of ghosting affect all along the Ridgeline to the left of your watermark. It almost looks like your camera has shifted down and to the left.

I do not know if this is related to your stars, or what might be causing it.

Steve Thomas

[justadude]

Steve, I agree about the shift down and to the left.  The odd thing is that on two separate occasions shooting night skies, with two different lenses, I have the exact same shift, degree of rotation, amount of movement, etc.  I'm pulling out lens issues since it was two different lenses, and rolling out tripod issues since the amount and direction of movement is identical in over 60 images, covering two separate nights of shooting.

[johnrmoyer]

This just my guesses, but I hope some of it might be helpful anyway.

I have EOS R5, not R6 II. One firmware upgrade improved the behavior of IBIS which was not completely reinitialized on waking after the camera had gone to sleep to save power. In that case, turning the camera off and back on again fixed the problem before a firmware update was available. Before the firmware update, I had put 2 raw files, one before camera sleep and one after waking, on my web server and described what I thought might be a problem to Canon CPS. I have no idea whether those 2 files helped Canon.

Also on the R5, when I use a lens with no electronics, I set the focal length of the lens in the camera menu because it seems to me I get odd behavior from the IBIS if I do not.

I guess that if tracking is enabled in the camera menu, the sensor might move or might lock onto something in the image that is moving or onto something that is not moving. I do not know much about astro, but I guess that turning on IBIS when nothing in the scene is moving might keep the sensor from moving.

When I use a lens with no electronics, I turn on IBIS (sometimes for shot only), set focal length for lens in camera menu, and enable manual focus assistance.

I have seen camera movement on a tripod when there was a distant magnitude 2 earthquake which we have many of here due to fracking waste water disposal.

So, my guesses for why some photos are good and some are not are because something changed. These are just guesses.

• Very small earthquake
• firmware bug resulting in something not being reinitialized when camera wakes from sleep
• Something changing in the camera as the camera internal temperature rises
• Camera forgets where to position the sensor when IBIS is disabled
• behavior in M mode seems to me different than behavior in Fv mode and I
   now use Fv where I would have used M in the past

I use exiftool to dump the metadata from 2 images that differ and use the diff program to find what changed between the 2 images. Sometimes i can find a difference, and sometimes not.

[justadude]

Wow, that’s a lot of good info, John.  Let me reply here and there (non-italic bold replies) through your ideas.  I’m still hoping to get this resolved without contacting Canon support since they will most likely want me to send the camera in.

This just my guesses, but I hope some of it might be helpful anyway.

I have EOS R5, not R6 II. One firmware upgrade improved the behavior of IBIS which was not completely reinitialized on waking after the camera had gone to sleep to save power. In that case, turning the camera off and back on again fixed the problem before a firmware update was available. Before the firmware update, I had put 2 raw files, one before camera sleep and one after waking, on my web server and described what I thought might be a problem to Canon CPS. I have no idea whether those 2 files helped Canon.

Also on the R5, when I use a lens with no electronics, I set the focal length of the lens in the camera menu because it seems to me I get odd behavior from the IBIS if I do not.

Not sure if this applies since I had IBIS turned off, and confirmed the following morning that the setting remained the same.

I guess that if tracking is enabled in the camera menu, the sensor might move or might lock onto something in the image that is moving or onto something that is not moving. I do not know much about astro, but I guess that turning on IBIS when nothing in the scene is moving might keep the sensor from moving.

I’m intrigued by this comment.  So if I have full manual lenses, IBIS turned off, focus manually, do you still think the sensor might be moving?  Or am I reading that incorrectly?

When I use a lens with no electronics, I turn on IBIS (sometimes for shot only), set focal length for lens in camera menu, and enable manual focus assistance.

I have seen camera movement on a tripod when there was a distant magnitude 2 earthquake which we have many of here due to fracking waste water disposal.

So, my guesses for why some photos are good and some are not are because something changed. These are just guesses.

• Very small earthquake – I’ll rule this out since it was the last two times I shot night skies – a few weeks apart – and each night had photos taken seconds apart where one was good, the other bad.
• firmware bug resulting in something not being reinitialized when camera wakes from sleep – Possibly, but from what I described above about photos taken seconds apart where some are good, some are bad, I’m not sure.  For example, six shot pano, each shot 10 seconds, taken maybe 10 seconds apart.  Images 1 & 5 are good… Images 2, 3, 4 & 6 are bad.  Another pano later in the evening had similar inconsistent scattered results.
• Something changing in the camera as the camera internal temperature rises – The outdoor temp dropped about 20 degrees in the few hours I was shooting (the joy of Great Lakes shorelines on summer nights) and got down into the 50’s.  I was not firing off enough shots consistently for the camera temp to really rise much.  Take maybe 10 shots at the most, walk down the shoreline for 5 minutes, take maybe two shots, etc. all evening. 
• Camera forgets where to position the sensor when IBIS is disabled – Intrigued again.  Would this happen as randomly as I described above with the 6 pano shots?
• behavior in M mode seems to me different than behavior in Fv mode and I
   now use Fv where I would have used M in the past – I have never played around with Fv mode at all… mostly M, and B, occasionally Av or Tv if I’m doing sports.  I honestly do not know how much of a pain (or how easy) Fv mode would be for astro work when I am often over exposing one shot and/or under exposing a different shot – and it’s a lot of back and forth.  Would Fv still be an advantage?  All of the videos I’ve seen show the camera finding perfect exposure, which is not something you want in astro since it will usually be looking at the foreground, not the background.  If I’m wrong, I’d love to learn more about this mode.

I use exiftool to dump the metadata from 2 images that differ and use the diff program to find what changed between the 2 images. Sometimes i can find a difference, and sometimes not.

[johnrmoyer]

Since the sensor is floating, the IBIS must always be powered on and holding the sensor in place instead of in the parked position. (Again, I am guessing.) If I had written the firmware, it seems I might have created a bug where the sensor did not stay in exactly the same place with IBIS disabled. With IBIS enabled and tracking enabled my EOS R5 will track a single star hand held.

I do not know much about astro, but that does not stop me. https://www.rsok.com/~jrm/2021Jun24_birds_and_cats/2021jun19_stars_IMG_1931c.html 

A starry night in Norman, Oklahoma on June 19, 2021 ;

Artist	John Moyer
F Number	1.4
ISO	800
Shutter Speed Value	6.2 seconds
Focal Length	50.0 mm
Lens Model	vintage MC ROKKOR-X PG 1:1.4 f=50mm
Hyperfocal Distance	Inf m

The lens is from a Minolta film camera and was made nearly 50 years ago. If I had stopped it down to F/2.0 there would have been less coma. My skills have improved some since then and the firmware is improved. We have hazy skies here lately with smoke and too much humidity.

• [MakerNotes:Camera] CameraTemperature : 34 C
• [MakerNotes:Camera] CanonFirmwareVersion : Firmware Version 1.3.1
• [MakerNotes:Camera] ValidAFPoints : 0
• [MakerNotes:Camera] ShutterReleaseWithoutLens : Enable
• [MakerNotes:Camera] MeasuredRGGB : 437 1024 1024 847
• [MakerNotes:Image] MeasuredEV : -7.00
• [MakerNotes:Image] TargetExposureTime : 6.3
• [MakerNotes:Image] ExposureCompensation : -3
• [MakerNotes:Image] ControlMode : Computer Remote Control
• [MakerNotes:Image] MeasuredEV2 : -55
• [MakerNotes:Image] ShutterMode : Electronic First Curtain

With firmware version 1.5 or later, the EOS R5 puts pitchangle and roll angle into the metadata. I do not know whether it is there for your camera, but I would expect it to be.

If you are a Canon CPS member, even the free level like me, they seem willing to download CR3 files from my web server when I report what seems to me a bug. 2 consecutive images, with and without the problem, might enable Canon to determine what changed between images. They can decode more of the metadata than can exiftool.

Good luck.

[Waddizzle]

Contacting Canon sounds good. Confirm if EXIF reports IBIS is disabled. 

[johnrmoyer]

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@Waddizzle wrote:

Contacting Canon sounds good. Confirm if EXIF reports IBIS is disabled. 

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I do not know about the EOS R6 II, but on my EOS R5, changing IBIS settings in the camera menu does not change "[MakerNotes:Camera] ImageStabilization : On (2)"  in the exif when I use a lens that does not have electronics.

[jrhoffman75]

You should contact Canon Support about this. Maybe something is causing sensor motion.

1-800-OK-CANON