michael.h.f.wilkinson

I used a Meade 6" F/5 Schmidt-Newton, GP-DX mount, and ASI183MC camera.

Couldn't resist tweaking the M51 image a bit to improve contrast This has a bit more detail, at the expense of some additional noise. More data needed, as ever

Using a better processing pipeline, I am getting a bit more colour out of M51 I also salvaged just 11 out of 30 subs of M3. Not bad, for such a short exposure

Lovely image of an unusual target

I have a grand total of 174 minutes (just shy of three hours) after weeding out all the subs wrecked by poor tracking, and processed the data a bit differently. I took the unstretched stack from APP, applied colour noise removal from FITSwork, then applied curves in GIMP for initial stretching, in which I leave the background pretty bright. I then increase saturation, and only do the final stretch on the image afterwards, allowing me to add saturation to the objects without blowing up the colour noise in the background. Oh, and I remembered that GIMP tends to flip the image vertically, when importing these FITS files, so I undid that. I hope to get another hours worth of data at least, in particular to the left of the image

Grabbed 2h of data on M51, using the Meade 6" F/5 and ASI183MC, after struggling with the mount I settled for 60s subs and got a run of 120 of them. Adding 30 darks, 30 bias frames and 60 flats got me this result. Yes, more data is needed, the background needs noise reduction, and I could perhaps play with chroma a bit. Still, pretty chuffed with this result. Next time, I think I will use 2x2 binning. Though I am not sure how that interferes with the Bayer mask

I played a little bit, but will give it a more serious go tomorrow, with twice the amount of data

Cheers, I will try again tomorrow

Which plugin? The ASCOM driver for the SkySensor?

Very nice. What scope and camera are you using?

I have been struggling to get PHD2 to connect to my GP-DX mount with SkySensor 2000 PC. I have set the COM3 port correctly, but when I set up the mount through ASCOM in PHD2, I get an error message that access to the COM3 port is denied. When I try to connect the mount to APT, it somehow borks too. Any thoughts?

Cheers, Alan. I need to get a load more data to be able to get more colour, I feel. I might be able to triple the amount of data coming night, we'll see.

Reprocessed the data from the 16th, this time using the built in debayer of Astro Pixel Processor, rather than some roundabout method, and this works much better, getting better colour, and suppressing amp glow to a much greater extent. Only a few tweaks with curves and crops in Gimp required. Way better than the previous version shown below.

BTW, my first solar filter (still have it lying around) was a Thousand Oaks glass filter for my C8, which gave a slightly yellowish image. For imaging, I later got a higher transmission Baader film one which I combine with the green solar continuum filter and IR-block filter, and these give considerably more detail.

The green solar continuum filter is great to bring out more detail in white light, but nothing beats H-alpha, not even Ca-K

I love using low magnification. The views of the Pleiades in my 6" F/5 Schmidt-Newton with the Nagler 31T5 at 24.6x and 3.34° FOV are just breathtaking. Likewise, I use the same EP in my APM 80 mm F/6 triplet at 15.5x, which gives stunning views of wide-field objects

A little 4.5" I built for the kids (they are much bigger now). Only drawback: no centre spot on the main mirror making it a bit tricky to collimate. I am getting a centre spot shortly, and will then probably donate it to the university's astronomy outreach group

As it is in such great shape, I do doubt it actually got installed on a ship, as most of the Imperial Japanese Navy was decorating various parts of the sea floor, after being relieved from the shackles of positive buoyancy by the end of the war I couple of vessels did survive in various stages of disrepair, which should shorten the search for candidates. The only battleship to survive was the Nagato. The only other names of major ships I have come up with are the heavy cruisers Aoba, Myōkō, and Takao, the light cruisers Kitakami, Kashima, and Sakawa, the fleet aircraft carriers Katsuragi, Jun'yō, Ryūhō, and Hōshō, and finally the escort carriers Kaiyō and Kumano Maru. Some further craft may have survived. I doubt smaller craft would be equipped with such big binoculars, though I might be wrong.

Amazing piece of kit. I think selling them to a collector and buying a new pair is indeed the best option, newer bins will have better transmission, better colour correction, and the option of inserting better EPs than the Erfle type used here. The photos suggest the optics are either uncoated or simply coated with MgF2. As I recall the latter reduces reflections from 5% to 1%. Modern coatings reduce that to 0.2%. Given a conservative estimate of the number of glas-air interfaces, MgF2 coatings would lead to a light loss of around 15%, compared to 3.2% for full multicoating. Improvements in transmission through the optical glass should be of a similar magnitude.

It was reasonably clear (despite the forecast for clouds) but slowly becoming hazier. I set up the Meade SN6 6" F/5 Schmidt-Newton on my old Great Polaris mount, with the Nagler 31 mm T5 yielding about 25x magnifcation at a FOV of 3.34 deg, ideal for comet hunting. I first had a quick look at Venus and the Pleiades, and then swung over to M81 and M82. Star hopping with an EQ mount at high declination is always tricky, especially because the SN6 has a straight-through, inverted-image (STII?) 10x50 finder. I therefore installed the ST80 as a 16x80 mega finder, and managed to pick up the galaxies fairly easily. They weren't nearly as bright as last night, showing that the transparency wasn't ideal. I star hopped to the location of the comet. Here I constantly thought I spotted a little fuzzy, very diffuse ball, in the correct location, but so difficult that I wondered if it was either some reflection in the optics, or "averted imagination". I therefore switched to the Nagler 22 mm T4, and spotted the same diffuse glow in the right location once more. Switching back to the 31T5 showed it stubbornly in the same place, so I consider that C/2019 Y4 (ATLAS) bagged. On a better night, or at a better location I do not doubt this would be a lot easier. Just as a sanity check I swung over to Leo, to have a go at M65 and M66. The latter was visible, but M65 was surprisingly hard, showing how much hazier the sky had become. Still, the SN6 showed its worth as a wide field scope. Next time I might well take it to a dark spot and set it up where it can really shine. Still, chuffed to have seen my 26th comet

That is superb!

Yesterday I managed to grab 1h 35 minutes of data with the Meade 6" F/5 Schmidt-Newton on the GP-DX mount (first attempt at DSO imaging with this combo). I used my uncooled ASI183MC, and subs of just 60 seconds. I did make darks and flats, but I still had to crop off the worst of the amp glow (still visible on the right). Next on the purchase list: a cooled version. Still, the image scale is good for galaxies, I would say. I must get guiding to work. Forecasts for coming weekend are good, so hopefully I can get the guiding up and running by then.

Afre a long break I have finally found time and good weather (with great seeing) to grab some sunlight once more. All taken with the little APM 80mm F/6 triplet and ASI178MM camera, with Lunt Herschel wedge, Baader Solar Continuum and UV/IR block filter for Wl, and Lunt B1800CaK module for Ca-K WL, grey scale: WL + pseudo colour: Ca-K, grey scale Ca-K pseudo colour: Ca-K part inverted: Ca-K part inverted + pseudo colour

That is a superb collection!

An 8" scope is a really capable instrument. I bought an 8" Schmidt Cassegrain telescope (SCT) on equatorial mount almost 25 years ago and still have it. Before that I had a 6" Newtonian on a Dobson-like mount, and it really got me going in astronomy. Later I wanted a bigger scope, with equatorial mount for imaging, and good portability, which made me settle for the 8" SCT. As a starter scope, that one would be rather over the top, however, and you pay a lot more for the exact same aperture as an 8" Dobson