ollypenrice

Well, you have the signal! Bravo for the staying power. Can I be honest about the processing? Two negatives strike me among plenty of positives. 1) I feel the colour saturation is shouting and I would simply turn it down by quite a lot, though this is purely subjective, of course. 2) There is clear evidence of posterization in the bright parts of the lower arc of the Bat. So I think the data would benefit from a softer process. You have the signal so there's no need to twist its arm, I don't think. The depth of the image, though, speaks for itself and is most impressive. Olly

Firstly Iapa has hit the nail on the head. Even with focal reducer your long focal length telescope has a tiny field of view with your camera, so you need to begin with an object which will fit on the chip. For this you need to be able to model your setup on a map of the sky - a PC planetarium. Iapa used Startools. I can't help because the one I use is out of production. Perhaps others could advise on alternatives? The first step in taking an image is modelling it on a sky chart in this way. As you've seen, all you'll get on Andromeda is a featureless fuzzy patch of light in the core. An enjoyable way to start might be to try the colourful double star Albireo, the neck of the Swan in Cygnus. It will work in short exposures, is easy to find and will easily fit on the chip. It will also give you an insight into trailing caused by tracking error and how long an exposure you can get away with. Good point about backfocus from Graeme, above, as well. Honesty corner: I would not throw money at trying to make the CPC work for deep sky imaging. A few succeed, the majority give up and move to a more suitable focal length and equatorial mount. Years ago I spent time and money on trying to image with a Meade equivalent and made no progress till I switched to a German equatorial and a small refractor, autoguided. Then it was great. (Given the small pixel size of modern cameras it is even more true that we don't need huge focal lengths any more.) Olly

We have four square topped piers in one of the robotic sheds and they can snag cables. The fix is easy: attach strips of metal pointing downwards and, if you like, reaching in to the column. These simply stop the cables hooking under the corners of the top. For anyone designing a new pier, though, I would advise against square tops in the first place, or certainly ones which overhang the column. Olly

That must, indeed, be low for you but the result is superb. The blue nebulosity will be the worst affected - but there it is. Gorgeous object. Olly

You're not alone! Olly

Well done, Carole, and best wishes to Kev's family. Olly

No, don't apologize. It turns out that the question carries a lot of baggage which is hugely location-dependent. It's interesting to discover that the world is not homogeneous! Olly

Risk? How would you feel about traveling overland at 118 feet per second (36 metres per second?) Take a quick look at something 36 metres away and say to yourself, 'One second.' That is what we do when we travel at the motorway speed limit in France. And we are worried about looking through a telescope at night? This is not a rational risk assessment. Olly

You're free to go off topic in a tank! 😁lly

I think this 'personal protection' thing is getting pretty weird, folks. If you go for a fight, how will it end? Any weapon you have may be turned on you, or another produced, and up goes the ante. By the far the best weapon to have about you is none, then it won't escalate. You are more likely to be attacked at a cash point - but how likely is that? Olly

I should just add the the boar hunters are certainly dangerous and shoot both each other and members of the public every year. The risk to the public is only about one in fifty million, though... lly

Make a noise and the boars will run away. Only an injured boar presents any kind of danger and they are usually on their own. Olly

This just comes down to good old fear of the dark. You're in far more danger driving to your site than observing at it. Certainly this is true in Britain and Europe where 'personal protection,' American-style, is illegal. We learn or inherit fear of the dark but it's an irrational fear since the daytime is far, far more dangerous. When I came to my present place, a dark, remote farmhouse in rural France, I would sometimes feel spooked in the night. Now I never do because, I think, I've 'unlearned' this irrational fear. While I would love to see wolves or boar at night - they are around - I know they are far too wary of humans to show themselves willingly and I remain disappointed. As for burglars, they mostly strike by day when they've checked you are out. And, by night, they are incredibly easy to detect. Of all the things you do, few will be as safe as observing the night sky. It just doesn't always feel that way. Olly

No. Olly

This isn't called galaxy season. Not by me anyway. Galaxy season is over, for me, by the month of June. That's at Lat 44. Olly

Don't confuse seeing with transparency. They are not the same by any means. 'Seeing' refers to the optical stability of the lightpath through the atmosphere. Does a beam from the object get stirred up on its way through? If so the information arrives in an already-blurred condition. The finer your sampling rate in arcseconds per pixel the more damage this does and it can very quickly become your weakest link. (Fast frame solar system imagers fight back by taking hundreds of very short subs and retaining/combining just the lucky ones which enjoyed a moment of stability.) Transparency, though, is self explanatory. It's very common indeed to have the best seeing on nights of imperfect transparency. Factors influencing seeing include warm air rising from houses/ tarmac, the elevation of the object (the higher the better), wind (which often causes different layers of atmosphere to have different temperatures) and the time of night. (Usually seeing improves, though not always.) Olly

I think it's equipment-driven up to a point, but only up to a point. If we take the example of any equipment setup, fix it and call it 'observatory x,' what variables remain? Ooooh, lots and lots. What target do you go for? How do you lay siege to it? Will it be a mosaic? What filters will you use? How will you blend them? How will you process the data? The million dollar question! So I don't think AP is equipment-driven, I think it is processing-driven. Olly

The distance between the flattener and the telescope can be (and is) adjusted by the focuser so the distance in question is between the flattener and the camera. Olly

The resolution in arcsecs per pixel which Vlaiv, rightly, makes the benchmark for discussion is controlled by the focal length and the pixel size. You can pair a shorter focal length with smaller pixels or a longer focal length with larger pixels and get the same sampling rate. My experience is that the advantage of a very large scope with large pixels over a much smaller one with smaller pixels is far less than one might expect. (I'm not talking about going to professional-sized instruments but, in my case, I'm comparing a 14 inch ODK and a 5.5 inch refractor.) Added to that, large pixels are becoming scarce with the CMOS revolution and the sensitive new cameras have small pixels. But may I suggest a step back from this high resolution brink? 🤣 You seem to be going into deep sky imaging with a shopping list of targets from the visual world. If you do that you will land in advanced imaging territory with all the problems that brings. Small targets, high res imaging train, precise guiding, etc etc. Why not start imaging the objects which best lend themselves to small setups? These are often not visual targets at all. They are too large for the eyepiece and too faint for the eye. Indeed, the fact that they cannot be seen visually adds to their charm. On top of that, the sky is full of them! Olly

It is a bit odd for the reasons you suggest. Could it simply arise from a change in local conditions? The seeing going off during the red sequence? (This assumes you did each colour in a block rather than scrolling RGB,RGB etc.) Olly

France and the UK both use DST (unfortunately) but France is always an hour ahead of UK time. Could this be your problem? (I'm in France as well.) There was a bug in the GPS time signal affecting older Meade GPS mounts. I vaguely think this raised its head in 2018 but can't be sure. You can risk updating with a fix but I found with my own elderly LX200 that the whole alignment process was far quicker, easier and more reliable with the GPS functions disabled. Olly

Our system does have soft start and stop built into the mechanism as supplied. Olly

I suggest a planisphere, a simple device which gives you an instant idea of what is in the sky on what night. Unlike a mobile phone, it has a large enough surface to show all that is up there. They are also very cheap. Astronomical observing is much more interesting if you know something of the science behind the faint smudges we see at the eyepiece, so a book on the basics would be a good idea. You know your son best so browsing at a large book shop, hands on, would let you see whether a given book would suit him. Olly

Gnu South Wales: very good, very good! I nipped outside and captured this snap of... Gnufoundland. Olly

Cue for my astronomical wingspan joke: Why does an albatross have a twenty foot wingspan flying south and a ten foot wingspan heading north? . . . . . . . Olly