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.

[Tronhard]

Hi Gary:
I am not an astro photographer, but looking at your images, they look like start trails to me, in the wealth of info can you provide your shutter speed data please.   As I understand it, you want to keep your exposure time to 10sec or less and if you exceed that, you get the star trails effect.

[justadude]

Hi Trevor,  I agree that this is what it looks like (star trails)..  But it’s not the case. Star trails rotate around Polaris (the North Star).  I was facing southeast on this shot.  No matter which direction I pointed my camera, when this happened, rotation seemed from the center.  The lenses used were 14mm a few weeks ago, and 15mm last night.  At this focal length I can do 20 seconds before I start to see trails.  Most of these were between 5-10 seconds.  

 I move around a lot when I’m at a location.  I’ll set up, take a half dozen shots, move to a different spot, do the same.  Each and every time I move, I make sure the tripod is solid in place.  Second nature since I’ve been doing night sky photography since the 1980’s.  Anyway, I was doing some 6 shot pano work.  5 seconds on each shot, loosen the ball head, rotate, tighten, another shot for 5 seconds.  For each of the pianos I did, some shots were sharp, while others look exactly like this, and by “exactly” I mean the same amount of movement/rotation.  

[Waddizzle]

Are you using a tracking mount?

[justadude]

No.  I do single shots, one here, one there, nothing to stack.  

[Waddizzle]

Are capturing multiple exposures at automatic intervals?  I think I am seeing multiple exposures, not star trails.  

This an extreme crop.  I think I see duplicate details. 

 

[justadude]

It does kind of look like it but no.  My camera is always set to single shot.  And again, light touch on the shutter, 2 second delay.  

[Tronhard]

Looking at the last image, there is movement on the horizon (including cables), especially on the very bottom right corner,  which suggests either camera or the vegetation is moving.   Was there any wind that could cause both, and/or were you near a source of vibration such as a rail track, or highway that would possibly cause vibration?

Do you weight the tripod down in the centre?
I assume you use a remote cable or delayed shutter being experienced in this.

[justadude]

Great questions again, but I can rule all of these out.  The movement in the foreground matches the movement of the stars.  I see it in each bad image, where each good image shows no foreground movement.  Breeze along the lakeshore was practically zero.  

We were there well after hours.  This one image posted was taken on a concrete sidewalk, next to the parking lot.  Three cars, all off in the lot.  Nearest person was my buddy taking photos across the lot.  Although it wouldn’t be out of character for him, he wasn’t jumping up and down (haha).  Lakeshore was beyond a tall dune, maybe 200 yards away, and waves were very calm last night.  Nearest houses are at least a half mile away, nearest traffic at that time of night might have been in town (3 miles), nearest railroad at least 10 miles.  

I weigh the tripod under needed conditions.  Last night it was not needed.  No breeze, my tripod is pricey and rock solid, camera mount is the same.  The 50 ish photos that turned out like the good photo I posted here show that.  The bad photos were so sporadic over the evening.  Going over the 100ish shots over the couple hours, it was like two good, one bad, one good, four bad, three good… and all of the bad ones show the same exact movement and rotation.  

I do use a delay of 2 seconds, same as I have for years.  I have a very light touch on the shutter.  Again, that’s just habit like a lot of us develop in time.  

[Tronhard]

Awesome detail Gary and it all helps to add to the puzzle! I shall ponder...

Can you replicate the same issue with different lenses and cameras: e.g.  different camera, same lens, different lens same camera?