StuartT

they were brand new. So I may just send them back. That video is for a different model. Mine don't seem to have collimation screws visible

hmm.. ok. Thanks. Slightly depressing. I found this video

Ok, so we had a bit of clear tonight and I tried them out. But I am seeing a double image. I was looking at Arcturus (as a very obvious target). Whatever I do (adjusting the eye width, the diopter adjuster in the right eyepiece) I can't get a single image. And I'm talking about a big separation - about 1/3 of the entire field of view Any ideas?

Brill! Thanks for this Kev. Very reassuring. Only had thick cloud so far of course!

That looks exactly the same as mine (I suspect they are all made by the same manufacturer). If so, you can set any interval you like. It's just that it measures the interval from the start of the exposure, not the end of it. This means you add the exposure time to the interval you want. Example. You want to take a total of 40 exposures of 30 sec each, with 5 sec between them. So enter your LONG as 30s then enter your INTVL as 35sec then enter your N as 40.

I just bought a pair of these and I wondered if any of you had experience of them? I've not had a clear night yet, but I tried them on a distant skyline object during the day and was a little alarmed at the degree of chromatic aberration. Are they uncorrected perhaps? I guess that might explain why they weren't very expensive (£100)

Thanks. This is encouraging as I have a Tokina wide angle on order. So fingers crossed! the video is remarkable! Who’d have thought it was that easy. Just tried it on my 18-55 though and it didn’t just pop out like his did. I didn’t like to pull too hard and risk breaking my lens!

thanks. Although I see that he didn't actually report back, so maybe he didn't 'cut a bit off' I must admit I can't imagine how that would even be possible! Some non-Canon lenses may not have that protrusion, I guess?

I did buy it new, yes. Although now I look at the website again, it does say at the bottom that it is not for EF-S mounts. I really need to read things properly!! So I very much doubt they would refund it. However, I would still be able to use it on the telescope with a T-adapter, so all is not lost. It just means I can't use it for wide sky photos, trails etc.

whaaaaat??? oh no!

I just got a Skywatcher CLS filter for my Canon. But when it's fitted, the lens won't go on (as there is now insufficient space for the lens to protrude inside the camera)! I thought these things were supposed to be able to work with lenses? At least according to this video

Right. I understand now. I was thinking of field rotation between exposures, but missing the important effect of field rotation within each exposure. I can see why that would be a problem. Thanks!

Thanks both. In fact, I was just using Stellarium to identify fun things to look at, then getting it to move the telescope to roughly the right place, then manually fine tuning position w the hand controller. I guess I was just wondering if there was some way to tell Stellarium what fine adjustments I'd made (and hence 'correct' it's understanding of the scope's true position)

Thanks for this. I'll check that thread out

Hi. You're sure more expert than me! Yes, I am aware of the dual problems of long focal length and AltAz mount. I guess I just wanted to see what might be possible, even within those limits. Hence why I restricted myself to 30s exposures. So far I have been mostly looking at the sun and the moon (where those issues aren't really a problem). But if I decide I really want DSOs I shall buy some new toys. Question though - since Deep Sky Stacker is able to deal with translation (during registration) why would field rotation be a problem for it? Can't it also rotate images as necessary?