Ags

Thanks @happy-kat. I am pleased too with the result, particularly at getting this definition at 1500 mm focal length on an AZ-GTi. Here is the results of using the global setting. Both are just quick stretches in Gimp. Before (using local alignment) After (Using Global alignment): Definitely more definition in the faint stars around the cluster.

I figured it out. There is a setting to apply alignment globally and not align every alignment point individually. I never understood why you would want to set Global, this is why - if you align at frame level then dim stuff stacks reliably. Use Local for the Moon, where there is always plently of local data.

I see it with all DSO targets. I suppose I could try longer subs.

Guess I could - but I am very close to the noise floor - so I may end up with the same problem just with bigger numbers. I do kind of do that as my camera is 14 bit but the data is so epicly dim I process it as 10 bit data, so I am stretching by a factor of 16. I am hoping an incoming 6.3 reducer will help but I wouldn't be using it with M57 anyway as it is tiny and bright.

Me too!

I am rejecting frames - in fact I am throwing away nearly half of them. Each frame is covered in a web of independent alignment points - and it seems if there is not enough signal from a star its local alignment point doesn't work. Here is my attempt at M57 from the same session. Focus was not the best on this one!

This nebula has phenomenal surface brightness.

Anyone?

I fail the reading emails test... And my current job is basically tech support by email and Teams! I am sure this job will make someone really happy! Especially if the annual performance-related bonus is paid in green and black!

I didn't see if this was full time, flexitime or zero-hour?

Forget the real living wage. Duz you gets staff discounts?

A Skymax 127 sits nicely on an AZ-GTi, while the 150PL would be undermounted on an EQ3 I think. You definitely don't need EQ for planetary imaging and I find my AZ-GTi and C6 very good for many applications. I studied images on Astrobin and came to the conclusion that 150 mm aperture was the least I needed for satisfactory images of the planets.

I was shooting M13 and M57 last night and I got promising but frustrating results. I was shooting with the following parameters: Scope: C6 @ F10 on AZ-GTi Camera: ZWO ASI 178 MM (non-cooled) Sequence: 500 x 333 ms subs Gain: 310 Binning: 2x2 ROI: full chip I processed in AS3! using 1.5 drizzle with Analyze set to focus on very small / high SNR. Why bin 2x2 then drizzle? Binning is to try help AS3 as with short DSO subs it can struggle to align the frames with all the noise. Drizzle then tries to get the detail back and unsquare the stars. Then I did a quick stretch in Gimp: I know a three minute sequence is not nearly enough but I have shot several - so the above is really just one "sub" with about 100 seconds of exposure (after 40% of the frames were discarded). Overall I am happy with the above, with the glaring exception of faint stars. The AS3! stacking seems to fail to align the faint stars resulting in any star below a threshold showing as a blob. My question is: how can I persuade AS3! to clean up the faint stars?

I do not use a barlow with my Skymax 102 because you already get high magnification (130-200x) using an eyepiece in the 7 mm to 10 mm range. On screen in the FOV calculator the planet looks small but when you have it in the eyepiece you will see that it is richly detailed and nothing like the dot you see on your screen. You have to remember that your telescope only gathers a fixed amount of light, and when you add a 2x barlow you are making the image 4 times fainter. When you look at a bright blue sky, do you see dots floating in your field of vision? If yes, you will see those same dots obscuring the planet when you use a very high magnification. For my pictures of the Moon and Saturn, I used a special astronomy camera (ZWO ASI 178 MM). That costs more than the telescope but you can buy comparable cameras (with a 30% smaller field of view) for less than half the price - and there are always second-hand bargains going. No eyepiece was involved - I inserted the camera in the diagonal instead of an eyepiece. For the Saturn picture, I also used a filter wheel and RGB filters to build a color image as my camera is monochrome. You mentioned Hyperions. I used to use a Hyperion 17 mm with fine tuning rings that gave me the options of 13 mm and 9 mm with the same eyepiece. In a Skymax 102 the hyperions are lovely eyepieces especially for planetary viewing. I had 3 eyepieces in the 9-10 mm range and the Hyperion with fine tuning rings definitely gave the best view. I sold my Hyperions when I got a different scope - I had a "fast" F5 Newtonian for a while and the Hyperions didn't give a good image there. I now use Explore Scientific 82 degree eyepieces which are in the same price bracket as the Hyperions but have a better field of view and they work in almost all scopes equally well. The Hyperions were a little more comfortable to use though!

Not my picture, but this is an impressive result for the Skymax 102: https://www.astrobin.com/291112/?nc=all

I have a Skymax 102 and it is a great scope for planets and Moon. I typically use a 10 mm eyepiece with no barlow - this is more than enough to show lots of detail on Jupiter while still keeping the image bright enough for contrast and color. In fact I often use a 16 mm eyepiece as the brighter image is easier for my aging eyes - and this still shows nice detail and color. I can go a little bit higher on the Moon, Saturn and Mars - for those I can use a 7 mm eyepiece (again no barlow). I have done some astrophotography with it, and I have attached some of my shots.

The 8-5 zoom is almost mythical in its reputation - there is nothing quite like it. I was so disappointed when these went out of production. At least I have the Speer WALER 10 mm - it's been the only constant in my small eyepiece collection.

You could try asking about the peripherals on https://space.stackexchange.com/.

I don't see many images of M97 for some reason... Good job!

I don't have the right stuff.

brilliant video

Yes, at high magnifications the point source approximation breaks down. But it holds true for most of the magnification range.

At the focal plane (where the field stop is ideally) the light from the star is focussed to a point. If that point is inside the field stop (no matter how big the field stop is), 100% of the light of the star goes on to the eye lens. For example, given the same scope a star will be the same brightness in a 3.5 mm Ethos with a massive field stop or a 3.5 mm planetary eyepiece with a tiny field stop. The ethos let's through more light with it's bigger field stop, but it does so by showing more stars not by making individual stars brighter.

I think what you are not getting is that there is exactly the same amount of light in the 10 mm and 1 mm exit pupil. That's because the 40 mm eyepiece is ten times further from the focal plane of the telescope (compared to the 4 mm eyepiece) so the same amount of light is simply ten times more spread out, resulting in a bigger exit pupil.

If I have an F4 scope and I use a 40mm plossl, the exit pupil will be 10 mm. This means most of the light from the star will not fit in your eye pupil. So the star will be fainter than if I had used a 4 mm eyepiece giving a 1 mm exit pupil. This only applies to point sources, extended object do get fainter at smaller exit pupils and reach a maximum brightness at exit pupil = eye pupil.