ollypenrice

That's lovely. Good decision! Olly

This would warm up the chip, though. Mirror lock or astro caera would be my choice. Olly

It's an appealing mount in some ways but in others it's a bit maddening. It ought to be a quick thing to set up but it isn't. That free standing triangular tray/tripod leg spreader is a faff and invites you to drop the wing nuts in the dark and lose them. The truth is that I have ended up leaving mine outside more often than I should because I don't feel like undoing those tray bolts, collapsing the tripod and bringing it in. As a result it has become rather ratty! In a nutshell I would like to like it more than I do but it gets on my wick. Olly

I wouldn't volunteer such trivia without being asked!!! 🤣lly

I guess the name comes from 'Rock of Gibraltar' and was chosen for its connotations of immovable stability. To the American ear, in particular, it may also evoke Rock Hudson whose name combined Rock of Gibraltar with Hudson River. The actor's production company was called Gibraltar. Perhaps his combination of substance and elegance was behind the choice of name? Pure speculation! Olly

You might find The Book of Nothing, by the late John Barrow, very helpful. It isn't devoted entirely to the non-emptiness of space since it also looks at the concept of zero, but it's characteristically well-written and enjoyable. It's high time I re-read it. Olly

The National Space Centre in Leicester is interesting. https://en.wikipedia.org/wiki/National_Space_Centre If you're holidaying in southern Spain then a spin up to see the domes at Calar Alto will also give you a great view over the Med to Africa. I cycled up there but that's not compulsory! Olly

It's best to measure the vignetting rather than eyeball a very posterized stretch. Just take the linear master flat and open it in software which lets you measure individual pixel values. I use my stacking/calibrating software, AstroArt, for this but lots of pre-processing packages let you do it. I get considerable vignetting in my Tak 106/2inch mounted filter/full frame CCD setup. The corners will give around 19,000 ADU when the centre is at around 23,500. That's a big difference but it calibrates out fine. Olly

I was going to suggest this as well. However, what will Registar think of Barnard's star, which will have moved? Will it reject the alignment request? With luck it will ignore Barnard's as an outlier and align on the others, but it will only put a fifty percent weighting on Barnard's in each position if it does. It won't give you a full application of both Barnard's images, it will be half star from one image and half background sky from the other. So what you'd need to in Registar would be align and crop/pad one image to fit the other and save it. Don't combine both in Registar. Then go back into Ps and paste the registered image over the reference image as a layer, select Barnard's and a bit of sky around it, select Inverse, delete the rest and flatten. Olly

The Camping and Caravanning club have an extensive list of 'Certificated Locations,' simple camping spots with a limited number of users and few or no amenities. Many of these are likely to meet your needs. https://www.campingandcaravanningclub.co.uk/ukcampsites/smallsites/ When I lived in the UK I envisaged using them widely for quiet breaks with or without astronomy but we hit a problem in that our fairly large coachbuilt motor home would invariably get stuck on damp ground and, at that time, few CLs had hardstandings. These breaks were an autumn-winter thing for us and, around Derbyshire, the ground was usually too wet. A car-caravan combination is less prone to sinking into the goop! Olly

The crux of arcseconds per pixel is that it states how much sky lands on each pixel. The more sky, the more light - but the less resolution of detail. I'd have this camera in a heartbeat, even though the just-under 6 micron pixels would be a little large for my Tak FSQ106. They'd still offer a 33% gain in resolution over my full frame CCD, though, and that still produces nice images at 3.5"PP. Also, that sampling rate would make it fast. It would be a match made in heaven with my TEC140, though. Relatively few optics will cover full frame and folks who do own such optics are likely to want full narrowband capability so this camera will not appeal to all who might be in the market for full frame. The other thing is that you need the computing power to stack and calibrate all those large files. Olly

Very good outer shell coming through. Olly

Again, just spot on. I never have anything to say about your images, Peter, except that they look as if they came straight from the sky! Lovely stuff. Invisible processing. One of these cameras just arrived here and I'm delighted to hear that theory and practice have agreed regarding the rejection of satellites through a large numbers of shorter subs. I suspect this is going to save AP from the Mad Musk. Olly

This policy doesn't always work for me. I specialize in losing 10mm spanners. Buying ten at a time has not solved the problem... lly

Yet again, thanks for this excellent information. I've done similar drillings myself but don't have a nice adjustable device like yours. I hope that a quick internet search and order will put that right! Olly

Yes, it's the Artsky adapter. I've ordered one. Olly

On the other hand the compression in this context is minor. You don't tighten the squidgy plate down with bolts perpendicular to it, which would apply real pressure, but only with that kind of jam jar lid affair which fits over it to hold it down. I'll talk to Paul tomorrow about the Pierro Astro Squidgeless Plate at a walloping 109 euros . Maybe that really is the way to go... All thoughts welcome. Olly

Was it Heisenberg who said, on his deathbed, that he had two questions for god, quantum mechanics and turbulence? He said he thought he might get an answer on quantum mechanics. If your pessimists are beyond both Heisenberg and god then I will happily ignore them! Your argument makes perfect sense and I will do as you did. Some bits of progress: Pier attacked with drill and angle grinder (surrounded by wet sheet to avoid spraying nearby rigs with iron filings) to allow optimal and collision-free placing of mount. We can image down to 30 degrees now. The pier originally had a square top. Electric focus arrived today and was duly installed: Camera also arrived. Am now going slightly mad trying to sort out the backfocus options and the merits of the Pierro Astro squidge-free adapter plate, an item which need not keep anyone but RASA owners awake! Olly

I'd have thought it would be up to you to decide. The only issue is the stability of the scope. I'd find out how close the rings have to be to avoid the rotation problem you have at the moment and keep them as far apart as possible within that limit. When drilling the dovetail to reposition one of the rings (maybe no need to reposition both?) I'd want to be fairly accurate so I'd mark up the centre line of the dovetail, centre pop the point of the hole, and drill using a sequence of three bit sizes on a pillar drill. This will keep cone error to a minimum but cone error is rarely much of an issue anyway. Alignment software allows for it. Olly

I'm mesmerized, though not alarmed, by the vastness of space but I was talking, years ago, to our baker's wife about what I did and invited her and her family to come up for a look through a telescope. She instantly declined, saying she couldn't look up at the clear night sky without panicking. She found herself overwhelmed by the vastness of it all and had the feeling that she might fall out into space and be unable to get back to Earth. Olly

More good info. Thanks. I think we need a short summer dewshield or even none at all, since it can be 22C here on warm nights. I'll ask my optical engineering guru about the optimal cable route but it looks as if it's an non-issue as long as you use a curve. Olly

Maybe it's not just the heat: the stirring of the air by the fan probably helps as well? But it's great to hear that dewing isn't a problem. Your cable loops from the camera are some distance from the corrector. I was going to run ours down the camera side and then in front of the corrector so as to be as far out of focus as possible but perhaps this isn't necessary. Olly

Paul's ordered one so your endorsement is welcome! Thanks, Olly

Yes, I had a thorough explanation of curved vane diffraction from an optical engineer who comes here regularly. We'll go for the semi-circle and won't run the guidescope to the camera hub because it's an extra cable in front of the corrector for nothing. Camera and focus motor are now ordered. Olly

That's perfect on all counts to my eye, Peter. Flawless and delightful. Olly