jambouk

vlaiv, in the absence of a guiding set up, or the ability to tune the mount or undertake a belt mod, is it worth the original poster doing a 10 minute sub with low ISO and maybe a filter to get a longer run of the trailing to see it in more detail? Is periodic error correction that useful if you have a non-permanent set up and are having to do a fresh polar alignment each night? James

The training seems uniform over the whole field of view, and uniform in nature and not jumpy which might hint at movement artefact from the camera. If this is reliably reproduced on all subs, I would make sure the balance is good, and I would do the polar alignment routine with polemaster twice. I would suggest the issue is a combination of imperfect polar alignment and reaching the limits of the mounts for unguided imaging. James

I’ve put some non-slip fabric in the gap - works a treat.

Can you post a high resolution image with the trails on for us to inspect and give details of the scope, camera, settings you use to image (including sub length) and how you polar align, and if you guide, and whether the trailing occurs in every image in a run or not.

OK. Looks like you are stuck with it as it is then. Thanks for getting back. James

Did you get this sorted?

Oh dear. We have a tendency to fiddle with things when there is no need. I am more guilty of this than most.* You seldom need to take anything apart in astronomy to clean it. Show us a picture of what you have and label them in a way that someone can give you meaningful instructions on how to reassemble it all. James * I really should have been a surgeon.

I don't know that mount, but it looks like an EQ5. I think the 150 PDS will be too "big" for the mount. If that is the mount you want, I would go for an 80mm refractor personally. To be honest, I would definately start with a refractor, just so much more compact and easier to look after, at the cost of cost and reduced light capture. Over the course of time, if you stick to astrophotography you will upgrade things, yet a good quality entry level "semi-apo" will be something you'll keep hold of for some time. Good luck with it all, and remember there is no right answer, you just have to ask for advice and pick the bits you like the sound of from all the range of opinions. James

If you mean the metal/plastic dials on the mount itself which can rotate and/or lock, then on the HEQ5 they are pointless, they do not help. Well the ones I've looked at are pointless. On my AZEQ6 the dials properly lock and can be used to set the hour angle when polar aligning, which is actually very helpful if you want a rough and ready polar alignment without getting on your knees. But the fact the circles on the HEQ5 don't fully lock, they are no use what so ever. James

It’s to correct for cone error, or rather reduce your cone error. I wouldn’t worry about it for now. If you are finding your GOTO accuracy is dire and exclude other causes, maybe revisit the topic. Enjoy!

Mount them at the same time, or at different times? Do either of these help? https://www.rothervalleyoptics.co.uk/baader-universal-quick-release-finderscope-base.html https://www.rothervalleyoptics.co.uk/rother-valley-optics-triple-finderscope-mounting-bracket.html

I’ve never seen or used one of these, but on conventional polar scopes one can screw the “eyepiece” part of the polar scope to improve focus - it’s a balance of the star being in focus as well as the etched reticle being in focus, and for my dodgy eyes neither are perfectly in focus. See if there is something to screw where you look through; use a distant horizon object in the day time to see if it has any effect. James

The precise time/date/altitude/latitude and longitude are just not necessary for a set up which is not permanently mounted AND parked. I wouldn’t bother spending hours trying to get the GPS thing working, rough and ready numbers will be fine (ideally within 10 degrees of your actual location north-south and east-west).

Handset polar alignment routine: https://stargazerslounge.com/applications/core/interface/file/attachment.php?id=395030

The location, time/date, altitude, three star alignment etc has nothing to do with your tracking accuracy. The tracking accuracy is mostly an index of how good your poor alignment is and how good your kit has been engineered. There isn’t much you can do about the latter, but you can take steps to work out how to improve your poor alignment. You have a synscan, so if your handset / firmware allow, there is a handset poor alignment routine you could undertake, I’ll post a link to it. What is the focal length of your telescope and imaging system? If more than 1000mm or so, then you may find even with perfect poor alignment you still get trailing stars at 20-30 seconds. James

Is there a Utility function in the menu tree? If there is, is there an Information option within that? Is there is, is there a Version option? If so, the firmware versions for the handset, and the database etc may be listed. If so, can you post what it says for all options? James

What version is the handset firmware?

Here is the update page: http://www.skywatcher.com/download/software/

Does your version of the firmware allow you to alter the way it offers alignment stars? For sometime you can make it list potential alignment stars by brightness, so the brighter, better well known stars appear first.

There is no shortcut that I’m aware of with the Skywatcher handset. James

Nice. It's fascinating to put a bit more flesh on the bones of names we've heard, but never really given much thought about. His obituary by the RAS can be found on the link below, and he is mentioned several times in a BAA article, which also includes a photograph of him: http://articles.adsabs.harvard.edu/full/seri/QJRAS/0003//0000048.000.html http://www.britastro.org/iandi/instruments-origin.htm James

Robert Garfinkle's long awaited book on the Moon has now been published. It consists of three volumes, each hardback and collectively they weigh about 5kg - it is a significant tome. It looks like it is a print on demand book, and my copies took about 18 days to arrive from ordering. I ordered through the Springer website, and the collective cost for all three, with the P&P from Germany was under £42. I honestly have no idea if this was a mistake or what, but it is ridiculously cheap. Even if the collective cost was £200 it would be worth it. The book looks amazing both from the outside and inside. Given the cost, I was dubious what was going to turn up, but this really is a significant work covering most things about the Moon from its role in art and history, to geology, observing, imaging, use of filters etc. A good proportion (a third) is devoted to the observable lunar surface features, with countless photographs, sketches and snippets of historical interest/importance. Volume three carries data, some more historical chapters, multiple maps from previous authors (with commentary and labels), a glossary and a very extensive bibliography. The format inside the book and the print quality is also amazing. Again I would be impressed if this has cost £200, but given it cost less than a quarter of this, I still can't believe they have got the pricing correct. I have no conflicts of interest as I don't know the author and have no connections with Springer, but if you are interested in the Moon, and fancy an all encompassing companion on the Moon, I would strongly recommend getting this. You can only buy the three volumes together. https://www.springer.com/gp/book/9781493916634 James

There is an option in the handset to turn down the brightness of the poor scope LED

Stick a hoover pipe in the polar scope hole on low suction and see if the other label will come out, but I wouldn’t stress too much about; bits of paper in there may improve the periodic error 😅

Thanks. I've ditched the two batteries in series idea for the time being, and just going to stick two big batteries in isolation,one connected to each of the outputs of the dual solar charger. If the two batteries are the same, and the load placed on each is the same, would you set the charging priority to 50:50? I'm still not really sure why the maximum I can send to battery one is 90%, and why I can't send 100% to battery one until its fully charged, then send 100% of power to battery two etc. Or is it sending 10% to battery two by default to at least put a bit of power into battery two to prevent it from degrading whilst battery one charges up? James