Stu

Lovely setup Jeremy. I have had a couple of Vixen GPs and love them, would really enjoy a GPDX, SkySensor works very well plus even at 20 year (+) old it will still interface with SkySafari! Amazing. I've just remembered, I also had a lovely Atlux with SS2000, great mount.

What a great looking setup. I remember seeing the original post and version one. Looks like it has moved on quite a bit! Good luck with remote polar alignment!

Sorry, I couldn't find them in a postable format. It sounds like you do not have a problem so should leave well alone. Good news.

Here are the instructions. They were provided by Skywatcher so I would assume they don't invalidate the warranty but it is worth checking. I have adjusted my mount and believe it is still covered by warranty (I certainly hope so!)

Well, to be clear there are two separate actions. First is the mechanical adjustment, which involves opening the mount and adjusting the gearing to reduce the amount of backlash. Do you have the instructions for this? Second is the software parameter which you can adjust to reduce the impact of the remaining backlash. This just speeds up the motor a little when the button is first pressed to reduce the time before the axis starts to move. The adjustment affect how long this quicker turning lasts. It does seem to be largely trial and error. No need to do a goto, just move the axis in one direction, stop and the move it in the other. See how much of a pause before it actually moves (best to be looking through the scope at a star at this point I think), then adjust the backlash parameter and recheck. There is an optimum point, after which the motion will jerk quickly before settling down, this means you have put too much correction in so should reduce it back again. Repeat for the other axis.

I think of it as how quickly the gearing responds to a change of direction. Zero backlash would mean it would start reversing direction instantly, lots of backlash means it would take quite a few seconds for the slack in the gearing to be taken up. You can make adjustments to the software so that the mount quickly takes up the slack which reduces how much this problem is visible. The better option is to adjust the gears to get rid of backlash as far as possible without causing binding.

Pretty sure that's the one I've got Gavin. There are much more expensive ones for doing measurements of star separation etc, but this is all you need to get accurate centering.

I have found the gotos to be pretty accurate with my mount, although sometimes a little off if going to an opposite part of the sky for instance. Making sure the mount is level might help this aspect. I generally do use a cross hair eyepiece but have still managed good accuracy by centering in a high power eyepiece. I have adjusted the backlash on my mount and it was very worthwhile. I found that there was a lot of movement on both axes i.e. I could move the scope a certain amount manually (even with clutches locked). I followed the instructions given and it is quite straight forward. On my mount the screws which hold the gears in place were lose which is what allowed so much movement. I adjusted them, making sure I tested it throughout the range of movement as there are tighter and looser parts. I got it as tight as possible without binding on the tight parts and then clamped it down hard. I suspect your inaccurate gotos may be a result of movement for this reason so it is well worth investigating, it is very easy to do.

Well you've got them now..... Generally, Zoom binoculars are best avoided because they often are lower quality or suffer from misalignment as you seem to be finding. I have a pair of 7x35 Chinon's and they give me nice widefield views, around 10 degrees. I would try them at the lowest magnification setting, are they still out of alignment then? If so, the only option I would think would be to open them up and see if there is any possibility to adjust the prisms.

You know how to hit a nation when we are down don't you Louis? Seriously though, the weather is a constant challenge, frequent cloud and the jetstream often wanders overhead to give poor seeing. Vapour trails from aircraft (I live near Heathrow but they also affect a lot of the country) contribute to poor transparency as well. Being on the edge of a large ocean, with prevailing winds blowing off it bringing constant weather systems and moist air our way makes life interesting! That said, I think we have had quite a few nights this winter where the transparency had been very good. I've seen plenty of observing reports which is great, and shows that people are getting out there and making the most of it. I've had more sessions this winter than last, definitely. There does seem to be a desire for people to have kit which can be setup (and taken down!) quickly so that we can exploit small gaps in the weather. I was going to say at least we don't get hurricanes, but parts of the country are currently being battered by 100mph+ winds, so not far off!

Excellent , I look forward to seeing the results

Not sure what the standard S8 camera app is like, but on iOS you can get apps such as Procam 4 and Nightcap which give better control of exposure and focus and make things easier to control.

Ray, I'm sure a man of your talents can give this a go. I think the camera on the S8 is very good isn't it? Have a go on the moon at least, just hold it up to the eyepiece and give it a go. Trickiest thing is getting the camera positioned on the exit pupil correctly, involves holding it away from the eyepiece a little normally, ie where you stick your eyeball! Have a look through my StuPOD thread for examples and some advice. I hope we get some M42 attempts, plus Jupiter of course.

Must be taken within the dates specified, but there is no mention of scopes having to be used so anything goes on that score, astro widefields, through binoculars, scopes etc etc.

Nothing to see here, move along now Thank you

Is field curvature not an issue which affects long focal length eyepieces more? I though higher mags tended not to suffer from it. Certainly the times I have seen it have been with ultra wide field eyepieces in short focal length fracs so I suspect an 8mm Plossl would not.

Yes, a shame, but I think it would probably be just that bit too much for it, particularly at high powers where you need it to be rock steady. I use mine on a Gitzo tripod, the original is certainly not up to it.

Fair enough Mike, it's not easy I agree. In the past I've just used BGOs of different focal lengths to try to get the mags as close as possible. Whilst I'm not in a position to get a DL even if I sold my DC (given the premium), I feel the same as you. The convenience and ease of use of the DC over the additional length and weight of the DL outweighs the small performance benefit. A DL would be too much for my AZGTi mount which is seeing a lot of use currently.

I think normal Binoviewer peculiarities are just as applicable with these scopes as any others. I find them fantastic for white light solar, very good for lunar, but cyclops suits me better for pretty much anything else. I can use my binoviewers natively for low power DSO observing but the jury is still out on whether that is better or not. I recall observing Sigma Orionis in both the DC and DL at similar times. The DL definitely showed the fourth component more easily on that occasion, but I know that the DC has done better at other times. They are obviously close, but you would expect the longer focal ratio to come into play to give that bit extra on good nights. Personally I would have observed with similar magnifications so that the views were comparable, rather than the same eyepiece as that is not a level playing field.

Thanks John, interesting read and based on a brief comparison with Gavin's DL it seems in line with my impressions. Ultimately the DL will provide slightly better views under excellent conditions at the cost of a longer heavier tube. Given that much of my observing is grab and go the DC suits me fine, but the DL makes total sense for those without that requirement.

Just tried this inside and it works very well. It doesn't seem to trigger immediately you get off horizontal so should be quite controllable. I can see it being very handy for panning around the face of the sun (amongst other things) observing different features without having to look away from the eyepiece. Thanks very much for the info

Thank you! Will give that a go

This sounds interesting Michael, but how do you do it? I have 6 Pro.

Awesome Gavin! Wonder how good that will be with the 160? I can't quite believe you got the Horsey in the Tak! Could you see it visually? So, apologies Helen, but I think today's StuPOD has to go to Gavin! Nice one.

That's nice Helen, nice and sharp, nothing wrong with your focus! Have you tried holding the phone a little bit away from the eyepiece? You need to be in the same position as you would put your eye i.e. at the eye relief difference. Closer to the eyepiece and you get blackouts all the time, or just nothing at all!