michael.h.f.wilkinson

Impressive!

Very nice result. Like the very natural processing.I am not sure if any further stretching would help

Really curious if the 8 deg claim really holds up. Usually these bins max out at 6.5 deg.

Created a quick mosaic with yesterday's data The lefthand side is definitely sharper than the right. Hopefully I can get more data later on the week to correct that

Quick process of data from last night: 1 h 40 min of H-alpha and 2 h of O-III using the APM 80 mm F/6, 0.8x reducer, and ASI294MM-Pro on the trusty Vixen Great Polaris. Quite a bit sharper than last night's effort. Rather pleased with this. Will make a mosaic of the whole Veil later

Cheers. I checked the Bahtinov images I shot and they look OK, but I have noticed that turning the locking screw of the focuser can shift focus slightly. There was also some high haze in the sky, which will not have helped either. I will try again for the Eastern Veil tonight

So here is the H-alpha-only version, with 45 minutes on the Eastern Veil added. It is a bit soft, but I am mainly pleased to have got the camera working

I think you are right. Will spend more time with the Bahtinov mask tonight

Finally got the new camera working. Got 2 hours of data on the Witch's Broom and Pickering's Triangle in H-alpha and O-III, and another 45 minutes on the Eastern Veil in H-alpha, using the APM 80mm, Tele-Vue TRF-2008 0.8x reducer, and the ZWO EFW2 filter wheel with Baader filter (LRGB, H-alpha, O-III and S-II). I have processed the first 4 hours of data quickly, and am quite pleased with the result. Stars in the corners aren't quite right, but I am getting there.

This morning I found the grub screws holding the focuser to the tube had worked themselves loose, and this is probably the cause of the tilt . I will first update APT and the ZWO drivers to see if that sorts out the issue with the ASI294MM-Pro. I also tried the ASI183MM-Pro, and that at first also had some hiccoughs, like the cooling going haywire (cooling well below the set point I had chosen), but that seemed to sort itself out using a different 12V power supply. Switching back to the ASI294MM-Pro with the better power supply still caused APT to freeze far too frequently to be of any use.

Ultimately managed to get 2 hours of data with the Canon EOS 550D, APM 80mm F/6 and 0.8x reducer. This was after a long struggle with the APT and the ASI294MM I recently got. The live view was constantly freezing, or when shooting single shots, the image would not load. Really maddening. I ultimately gave up and used the old 550D, but I feel the camera wasn't quite square to the optical path, as stars in the corners aren't good. Still, it is the first capture of the Vail with the 80 mm. Not too bad from an old sensor under Bortle 5-6 skies

Managed to get the scope out to a dark spot outside of town, where the southern horizon is a lot clearer than from my garden, so I could have a go at the gas giants. Seeing wasn't too bad, but the low altitude made life hard. Aimed at Saturn first, then went to Jupiter, and returned to Saturn to check if seeing was a bit better. First image taken at unit gain with shorter exposures, second with slightly longer exposures. Each image is a stack of 2,000 out of 10,000, stacked with AS!3, sharpened in Registax. Finally Jupiter, with the GRS about to turn away All images taken with my Celestron C8, Siebert Optics 1.3x tele-centric Barlow, and ASI183MC camera

Superb detail captured in those shots!

Nice one! Also nice to see the galaxy in the background

Stunning catch!

This is one of those "it depends" issues. A top of the line apochromatic refractor should beat a well-figured, well collimated Newtonian reflector of the same aperture, although things will get very close for a slow Newtonian with small central obstruction. I had a 1/10 lambda 6" F/8 with 24% central obstruction that would give many a refractor a serious run for its money. However, a 6" F/8 achromat will show chromatic aberration, and a 6" F/5 achromatic refractor will be very much worse on planets than the aforementioned 6" F/8 (or even F/5) Newtonian. The price of a 6" F/8 apochromatic triplet refractor is roughly 10 times that of an 6" F/8 Newtonian. For the price of the 6" apochromatic triplet you could easily buy a much bigger Newtonian (10" or 12") with quality mirrors, and under good seeing they would be much sharper on planets.

I have used FITSwork to edit headers: https://www.fitswork.de/software/softw_en.php

The stars in the corners aren't that great. It probably would benefit from stopping down a bit

Will try and have a visual shot again today (weather permitting)

As a rule, no EPs are used, only various cameras, spectroscopes, and other gizmos.

I have a series of Delos (6, 8, and 14mm) and Pentax XW (5, 7 and 10 mm) EPs. Other than focal length, I could not really say which is better. Their performances are so closely matched, it is really a matter of seeing conditions that dictates which I prefer at any given point in time

It may take a while before they trickle through, of course. Many "new" glasses are of course variations on existing ones, with subtly different properties, but a larger variety of glasses means more degrees of freedom in design. I have also seen some stuff on 3D printed optics. That could lead to more affordable prototyping or production of small runs.

If aspherical surfaces become cheaper, it becomes more affordable to incorporate them in designs. I haven't heard of specific glass types, but I know from my colleagues at the Kapteyn Astronomical Institute and SRON (the Dutch Space Research Foundation) that the big producers of optical glass are still developing new stuff. Much of that finds a way into camera lenses (much bigger market), or spotting scopes and binoculars, of course. You can definitely see improvements (generally first at the high-end section of the market) in recent years. I compared the Zeiss Victory SF 10x42 side by side with the earlier Victory FL type, and there are small, but definite improvements to be seen. The Abbe orthoscopic design itself was based on classic crown and flint glass elements from the 1880 (and no coating, MgF2 coatings were introduced by Zeiss in 1935 or thereabouts). Had Ernst Abbe had modern ED and fluorite glass at his disposal, who knows what his designs had looked like.

ZAOII EPs are next to useless for those who wear glasses, for all their excellence. All optics are a compromise, and the ZAOs and other Abbe orthoscopics and monocentrics sacrificed eye relief and FOV. Having cylindrical astigmatism, I MUCH prefer the Pentax XWs, TV Delos, and Vixen SLV/LVW types. ES is also on to something with their 92 deg EPs (sadly, just two, but happily, I have them), with better eye relief than the Ethos range. These ES 92s replaced my already excellent TV Nagler type 4, giving more FOV, but more importantly sharper images. New types of glass, and cheaper production of aspherical optical surfaces are just two areas which could lead to even better eyepieces.

Indeed, with a star diagonal you are fine, but without you need a huge extension tube. Star diagonals have a long optical path, after all (Amici prisms are worse). If you place the diagonal in the powermate, rather than the reverse, you are in trouble. The 2x teleXtender (I have the Meade version) doesn't really have an issue like this.