gorann

Well, if you keep your optical path clean, checking and air-puffing each filter before the session, and have a relatively small chip (like the ASI1600) in relation to the image circle of the scope, you do not need anything but darks.

I like everything about it Richard, both before and after the squid ollymagically appeared, and maybe the squid is the ice on the cake. Just lovely!

As everyone says, there is no single telescope that can do it all, so after a while we all seem to end up with a bunch of them. You initially indicate an interest in a 5" apo refractor. To add to your choices of an intermediate focal length scope you could have a look at a new 6" doublet from Altair Astro that received a very favourable review in the latest issue of Sky at Night Magazine. Appears to perform like a triplet but at half the price: https://www.skyatnightmagazine.com/reviews/telescopes/altair-150edf-apochromatic-doublet-refractor-review/

Wonderful initiative Grant and Ian! I can see that it will bring some great discussions and suggestions about equipment and processing here on SGL, and giving those of us being under cloud cover (right now apparently eternal where I am) a welcome opportunity to keep up and improve our processing skills. And you will have a devoted crowd to test your new equiment! Everyone wins. I am curious about the telescope - I cannot find it on the FLO site. What is the advantage of two ED lenses?

Looking great Dave! Interesting to read that APP outperforms PI in calibration and stacking! Any thoughts about that Wim? @wimvb

Allways happy to contribute some comparative animal physiology to the discussion here Wim, but I rarely get challenged to do it. I doubt that our vertebrate brains can take advantage of phase relationships of the light entering our two eyes, but maybe insects can do it, they are almost from another planet.

No accident Olly, all vertebrates have two brain halves, even fish. Our eyes are each connected to both brain halves so the info from each eye are processed by both brain halves (more precicely the optical cortex at the back of our brain halves). However, there is a devision of labor so our right brain half takes care of the left field of view and vice versa. Fish are even more specialized since their left brain half only receives information from their right eye (their optic nerves cross over), and vice versa. It has been shown for at least some fish that they use one eye and brain half to look out for food, and the other eye and brain half to look out for predators.

You have a good point there Olly, and I should know, being a professor of physiology. I after thinking about it, and after doing the simple experiment of closing my eyes one at a time while looking at the computer screen, I think you are perfectly correct: getting the same amount of light into each eye does not equate to getting the double amount of light into one eye. So my conclusion is that looking through a 6" telescope with one eye gives your retina and brain more light and information than looking through two 4" binoscopes with two eyes. So, with one eye the 6" mono scope wins, because adding a bino viewer to a 6" single scope, which halves the light getting to each eye, will reduce the light to 50% to each eye so it would be equivalent to looking through a 4" binoscope with one eye. So the conclusion is that if you want to get as much light and detail into your brain as possible, go for a 6" mono scope with a normal star diagonal where you look through one eye only. I hope that made sense! EDIT: To add to his, the only advantages for us and other animals of havng two eyes are to get stereoscopic vision, that aids in determining distance, and in getting a wider field of view, but none of these advantages applies to a bino telescope. EDIT 2: That said, as we are binocular animals we probably feel more confortable looking through two eyes, but then we have to accept loosing brightness and information by only geting half the light to each eye if we use a bino viewer or two small telecopes rather than one big one.

Would be exciting to point that scope at something near zenith - I can see myself falling into it.

Great image Dave, well worth the outstanding effort. I did notice that the stars were maybe unusually sharp but did not mind, even liked them, but then I am just an ordinary pixel peeper, not such as scientific pixel peeper as Vlad, but he may have a point. Excellent nevertheless!

I have to agree with Adam - I never found green in astroimages pleasing even if I am a biologist who loves all the green down here on earth.

I stopped subscribing to printed astro magazines years ago, and at the time when I did subscribe, it was a UK magazine (Sky at Night) even if I live in Sweden. I thought at least Sky at Night saw itself as an international magazine (as was also pointed out in the thread above) so from my perspective I would find it very odd and unfair if UK photographers were favoured. If people living in parts of the world prone to be cloudy or light polluted should be favoured, then that would at least include most of northern Europe. One reason I stopped subscribing was that I find all the astrorelated info I want or need on the net, including SGL. And if I want to look at astrophotogaphs from fellow amateurs I can do it here and on Astrobin. I picked up a copy of Sky at Night on Manchester Airport a few days ago to have some reading on the plane back. It had a few interesting equipment reviews but looking at the images published there was mainly frustrating. They were too small and magazine printing makes them too grainy and I have no idea how well the colours were reproduced. That reminded me why I do not subscribe to printed magazines any more. The net is a much better outlet for astrophotography, and there we can also get feedback on out images, so personally I have never considered submitting images to a magazine.

Beautiful Ola! I assume this is reprocessed data from your archive, or did you find a hole in the eternal cloud cover we have now?

Or maybe try to tighten your clamps and screws a bit more Carole😉

I agree, this cannot be cone error. The two scopes sitting maybe 30 cm apart are initially pointing at the same star, many light years away, so their optical paths must be absolutely parallell. If they after a flip do not point exactly the same way, one or both must have sagged a bit after the flip. Maybe the saddles or maybe the image train have shifted, but it is not cone error, it is gravitation. PS. As I understand it the term cone error means that a scope is not being exactly in plane with the polar axis, which is something different.

Very nice Ceph! Regarding the stripes you mention, have you tried the Canon Banding Reduction in PI (under Script -> Utilities)? It often works great.

I side with the majority: the more natural look of HSO appeals to me. Great image by the way! What scope and camera?

A dual rig is a great idea for the obvious reason that it gives twice as many hours of data! So it is well worth the effort especially with the weather we have up here in northern Europe (Britain still included). In one of my two obsys I am running a dual rig with two Esprits (100 and 150) and two ASI cameras (071 OSC and 1600mono) on a Mesu 200. I use ASICAP for capture on two separate laptops, one for each camera. To me it seems to be the safest and simplest option if you have more than one laptop, as you have. With one of the laptops I also control the mount with Cartel du Ciel (recommended by Mesu so I went for it and it is free) and PHD2 (I use an ST80 and a small QHY for guiding, sitting on top of the Esprit 150). I have never dithered with these cameras and do not see much need for it as they are rather noise free. Balancing a dual rig is a bit more complicated as more things need to be balanced. This is what I did: I took each scope (with all gear attached) and put it on the obsy floor with a pencil under the dovetail bar, and moved the scope over the pencil until I found the center of gravity, which I marked on the bar with a piece of tape. I did this with both scopes. (I used a pencil as I had one at hand - any round bar would of course do the job). I then put the dual-rig bar on the floor with the pencil under it and attached the scopes in the saddles with their center of gravity centrally in each saddle. I then slided the dual-rig bar over the pencil to find and mark the center of gravity for the whole set. I then removed the scopes and put the dual-rig bar into the holder of the mount with the marked center of gravity centrally. The scopes were then put back on (center of gravity centrally again) and I finally balanced the RA axis the usual way with the weights on the weight bar. Did that description make sence? To align the scopes I use one of these as saddle for the lighter scope: https://www.firstlightoptics.com/misc/jtd-dual-rig-telescope-alignment-saddle.html

Nice! How do you make an imaging request to them, who are allowed to do it, and what does it cost? Here is the current weather forcast for where I am in Sweden, not unusual for November:

I look forward to see the result of this collaboration!

Yes, but I think that it would not cost more to get a single larger scope with binovewers. For example, instead of two 4" refractors you could go for a 6" refractor and binoviewers. It also seems a bit more practical but obviously no to cool😉. However, it could be that the small prisms of affordable binoviewers gives a smaller FOW than a bino-telescope.

Thanks Rodd and Alan!

That is an excellent image in every respect. It has everything from Ha nebulae to dark nebulae and galaxies. Should be an astronomy book cover. Congratulations Richard!

I have a feeling that the thread on the Portuguese site is rather old. You could restart it here Peter by posting images of your binoscopes!

I expect they are both excellent scopes, but the Esprit may have the edge especially if you one day want to sell it. Esprits have a rock solid reputation as far as I can tell - never read a bad review about them.