Vixen Polarie: help desperately needed, please!

[Guest]

I'd be immensely grateful if anyone might be able to offer advice for a problem I've been having with my Vixen Polarie, please. (Apologies in advance for the long post.)

Although I've had the Polarie since 2014, I'm still very much a novice, probably for two reasons: I live close to Manchester so clear nights are that rarest of things(!) and it's difficult to overestimate how dense I'm probably being about problems like these...

I've been delighted with the Polarie — last year, I visited a dark sky site and took my first proper photograph of the Andromeda galaxy. I'm certain it was more by luck than anything I'd done, but I was so awestruck when the galaxy popped up on my camera's LCD that I think that one photo has kept me going ever since.

Shortly after this, I began having problems with star trailing, though. When it first began I hadn't thought it was anything significant as I kept noticing embarrassing things I'd done incorrectly, such as not attaching the Polarie to the tripod tightly enough, causing it to droop. But even after making a conscious effort to make sure that everything was (hopefully) correct, I'm still experiencing the problem.

I should probably mention that I've been using a Canon 650D with a 50mm f/1.8 STM lens — from what I've read, it seems this is within the weight tolerances of the tripod (a Manfrotto 055XPROB), geared head (a Manfrotto 410 Junior Geared Head) and the Polarie. I also use the polar scope to try to align accurately.

My initial thought was that it was a problem with the ball head that my camera sits on (a Manfrotto 496RC2). I'd felt that it hadn't been locking quite as tightly as it had when new and, even when fully locked, I seemed to be able to move it slightly. I contacted Manfrotto to ask if there was anything I could do — they have offered that I can return it for a warranty repair, but I just wanted to make sure that it was the ball head that was at fault before sending it in. One thing I have noticed is that the star trails are sometimes comet-shaped, or even multiple stars side-by-side, which made me suspect that the head was slipping somehow. The other night, though, after leaving my camera outside for five minutes, I came out to find that the whole head had semi-unscrewed itself from the Polarie and was twisted to one side — the ball head itself was still locked in place.

Last night, thinking this was the problem, I double-checked that the ball head was tightly screwed on to the Polarie... but I still had trails. One thing I have noticed, though, is that if I take a picture soon after I've attached the camera, the trailing is much worse than if I leave it for a few minutes to settle. I don't remember having had this problem when I first bought the Polarie and ball head, though. Hopefully, these 100% crops show the problem:



The photo above was taken as soon as the camera had been placed on the ball head, whereas the one below was a few minutes later (nothing else had been changed).



These two photos were, again, taken a few minutes apart, but the first one shows the comet-like trails I sometimes find:





One thing that's concerned me has been noticing some marks scored most of the way around the Vixen's tracker section, hopefully visible in the photograph below. Up close, they look like very small indentations. I wondered if anyone else's Polarie might have them, too? Could these interfere with the accuracy of the tracking? I've always tried to be extremely careful when mounting the camera and made sure to tighten the two bolts securely. When I was trying to adjust the ball head last night, though, the metal part that attaches to the Polarie rotated along with the ball head, leaving me cringing at the thought of more scratches appearing. 



Sorry again for the long, and jumbled, post. It's just got me completely baffled. I suppose what I'm really concerned about is, is this a problem with the ball head or, more worryingly, the Polarie itself? Or something I'm not doing correctly? And do I need to be concerned about the scratch marks on the Polarie?

Thanks in advance for any help.

[JB80]

Mine has far more score marks than that on it, I would doubt that is the problem.

 How long are your exposures?

I had similar issues in the past with mine, from memory I tried a number of things but it was a while ago now.
I guess the very first thing and this is far trickier than it might seem is to make absolute certain that everything is as tight as it possibly can be and do double check, slippage can cause these errors easy enough.
Since you say it improves after a while I would then look at things like the tripod and ground it is sitting on, even on cement I was getting vibrations at times just from me moving around. While the photographic tripods are perfectly fine with the Polarie they can be a little light so maybe you can try weighing the tripod down by hanging something heavy off it somehow. I went through two photo tripods before settling on an EQ-2 mount.

Another thing I had trouble with was mirror flop, basically every time the shutter would snap shut or open it would cause a slight wobble on the mount and it would definitely test out how tight things are. Not sure how I solved this but a heavier mount helps for sure, although I don't think that is your immediate issue.

It's tough, you sound like you are aware of the tightening up issues and everything and all I can really suggest is to keep doing that right and maybe weigh down the mount a bit. If there is no improvement then I guess it needs more trouble shooting.

[Guest]

Ah, thanks — it's a big relief to know that the score marks are normal.

Apologies, as I was posting I had a feeling there was something I'd forgotten to mention! The exposures were one minute each.

Recently, I've been setting the tripod up on a flagged patio, but I used to set up on a second, raised patio area where I didn't have any problems — it's perhaps a coincidence, but it's worth checking out. (We do live fairly close to a main road.) I did once try placing the Polarie on the lawn but experienced some pretty severe trailing. The ground had felt firm but I'd still wondered if the tripod was slowly sinking into the ground under the weight of everything.

I'll definitely try weighting the tripod. Just the other evening, I'd been mulling over whether spreading the legs slightly farther apart could help, but I'm not sure. A few nights ago, I had tried using mirror lock-up, too, just on the off-chance the mirror slap might be causing some problems. Although I still had some trailing, my test wasn't exactly scientific... I will try some back-to-back tests with it turned on and off.

Thanks again for your suggestions. I'll give these things a try and report back on how they go. 

[steppenwolf]

Something else to check is that you don't have any trailing cables (perhaps from an intervalometer?) snagging on part of the equipment as this can easily cause star trailing.

[Guest]

Thanks for your suggestion, I'll make sure to check that.

When I first bought the ball head, the ball itself had been coated in quite a lot of grease. Over time, though, it seems to have distributed over the ball in quite an uneven way, with some gathering at the edge of where the ball meets the outer case. Might it be worth me removing any excess, just to make sure that this isn't contributing to the ball (possibly) slipping? (I didn't like to do it without checking in case I might be opening myself up to further problems down the line.)

[Glimpse111]

On ‎22‎/‎08‎/‎2016 at 19:13, Matthew46 said:

Thanks for your suggestion, I'll make sure to check that.

When I first bought the ball head, the ball itself had been coated in quite a lot of grease. Over time, though, it seems to have distributed over the ball in quite an uneven way, with some gathering at the edge of where the ball meets the outer case. Might it be worth me removing any excess, just to make sure that this isn't contributing to the ball (possibly) slipping? (I didn't like to do it without checking in case I might be opening myself up to further problems down the line.)

Hi Matthew,

Did you manage to fix the trailing problem. I am having the same sort of problem but could easily be that I am not aligning it properly. I will be worth knowing if you manage to fix the trailing.

 

Regards

AJ

[Guest]

Hi AJ,

Sorry to hear about the problems you've been having with the Vixen, too. And apologies for my late reply – I was on holiday last week which, funnily enough, was the reason I'd been so concerned when the Vixen had begun trailing; we were lucky enough to stay near a dark sky site in the Peak District. Although I am still encountering some problems, I think I've (hopefully) figured out what's going on.

I tried to systematically work through JB80's and steppenwolf's very helpful suggestions, and it seemed to be moving to a different spot in the garden that instantly got rid of the trailing – but it turned out not to be because of traffic vibrations as I'd imagined. Where I was having problems with trailing, our house blocks the view of the southern sky so I could only ever image facing north. As soon as I moved to a spot where I was imaging the south instead, everything was fine... until I moved the camera to point northwards again.

Thinking that facing north might put a greater load on the head (facing south looked to create a balanced 'line' coming out of the Vixen), I tried wiping some of the excess grease off the ball head, which did seem to help (although it's perhaps a coincidence).

Last week, at the dark sky site, I was hoping to try imaging the Cygnus/North America Nebula area of the Milky Way but, when I pointed my camera upward, it instantly began badly trailing over a five minute exposure (it'd seemed fine when pointing at M33 earlier). Each time I tried another exposure, though, the trailing noticeably improved, almost as though the ball head was gradually settling. For one last attempt, I gave the locking lever on the ball head a final tighten – to be honest, beyond what I'd normally feel comfortable doing for fear of it snapping. Unexpectedly, the trailing seemed to disappear completely. I'm now (I think) fairly certain that it's the ball head that's been causing the problem (although if anyone could point out anything I've missed, I'd be very grateful).

I'm now feeling torn about whether to return the head for a repair or to perhaps choose a different one. One of the things I've found most difficult with the Manfrotto 496RC2 has been that, as the locking lever swings down, it occasionally catches on one of the Polarie's two screws and so won't lock in that position... But what brand and model I'd choose instead, I'm not sure!

Sorry for the long post – if there's anything else I can try to help with, please just let me know.