michael.h.f.wilkinson

Collimation of an SCT is rarely needed if ever. I took a shot o Jupiter and moons in about 2015, and it showed albedo spots on Ganymede, twenty years and many travels after I bought it, and I had never touched collimation in all that time. I checked it every session, but always found it to be fine.

Impressive list. Mine is quite a bit shorter over the last 42 years: 1979: Home-made 6" F/8 Newtonian (Real planet killer) 1993: Rebuild of the 6" F/8 (new octagonal wooden tube, better flocking, baffles added, better focuser) - sold in 1995 to finance GP-C8 1995: GP-C8 -still with me 2011: APM 80 mm F/6 triplet - still with me 2013: LS35THa donated to outreach programme of Kapteyn Astronomical Institute in 2015 2014: ST-80 guide scope bought - still with me 2015: Coronado SolarMax-II 60 mm - still with in my office, for the odd H-alpha session at work 2017: EQ3-2 mount added to arsenal - still with me 2019: GP-DX mount added to arsenal - still with me 2020: Meade SN-6 6" F/5 Schmidt-Newton. Awesome wide-field visual and imaging scope, not going anywhere soon Only the GP-C8 and APM 80 mm were bought new, as were the mirrors etc for the 6" F/8 Newt

Thanks! It got me my first prize in the SGL eclipse imaging challenge

It is real, although pseudo colour and some sharpening of solar detail by stacking segments of the same 1000 frame sequence without interfering birds has been done. The movie is here

I wonder what question you might set with this one

Any of mine may be used as well

I have Nagler, XW, ES 92 deg, Delos, and LVW EPs and none fell down in fast scopes (at least down to F/4.1). Only the MaxVision 24 mm 68 deg fell down at that F ratio, but it is fine at F/6, and is claimed to work well at F/5. Only a first class ortho could perhaps better the views in a Pentax XW, but at the expense of FOV and eye viewing comfort. My widest EP is the ES 12mm 92 and it is superb. I used to have two orthos: a 25 mm Ioved, and a 5 mm I hated. A key problem with the classic Abbe ortho is that it is a scaled design, and that therefore the eye relief is a fixed fraction of the focal length. The views at the short end, with your eyeballs practically gleud to the lens are very uncomfortable, especially with glasses. The same holds for Plössls, or any scaled design. Moving to long eye relief EPs has just improved the comfort of viewing dramatically, and the reduction of strain means it is much easier to pick out fine detail. In theory, picking out faint detail should be better with a reduction of the amount of glass, and in particular the number of the air-glass interfaces. However, having the image bounce up and down because your glasses nudged the EP yet again rather offsets the subtle advantages that might be obtained. Just my tuppence. I still have one ortho (25mm for solar H-alpha, and with 20 mm eye relief)

Here are the constituent monochrome images H-alpha O-III S-II The H-alpha really blows the others out of the water

10x50 is a nice size, and Nikon is a good brand, so you won't go wrong, as long as you steer clear of zoom versions. I generally use my 16x80 Helios Lightquest without monopod for quick session, although I realize most find this a handful. An excellent source on choosing binoculars can be found here: https://binocularsky.com/binoc_choosing.php

Yesterday was very clear indeed, and I made the most of it by grabbing a lot of narrowband data, primarily S-II, which had been cut short by clouds to just 18 minutes previously. I grabbed 2 hours 12 minutes of S-II, and another hour of H-alpha and O-III each, bringing up the totals to 2.5 hours, 2 hours and 2 hours for the three bands respectively. Although the S-II band now does show some nebulosity, it is still completely overwhelmed by H-alpha, so SHO doesn't work that well Trying to stretch S-II introduces way too much noise, so I will have to get more S-II data (Thursday, maybe) HOO is the next to try: This works quite well, and is clearly better than my first attempt (with half the data) Finally, I had a go at HOS, and I must say, I find it quite appealing: With any luck, I can get lots more S-II data on Thursday and Friday (aiming for an additional 4 hours), and I will also try to get an additional hour of O-III and H-alpha, it time allows

My min worry is that it might be geared towards spotting scopes and terrestrial viewing, so it might have issues with angular magnification distortion. Still a very interesting zoom EP

Got the camera set up early, started imaging at 19:30, have already captured 2 hours of S-II, now grabbing an hour of O-III, ending with an hour of H-alpha. Will add these data to those of February 27. The set up S-II (very faint) O-III H-alpha

Had a brief lunchtime session with the SolarMax-II 60 again. Only a small prom right down south visible now, and a small filament near the southernmost edge of the disc. Two small ARs could be seen, the larger south and east of the centre, the other closer to the edge in a more north-easterly direction. Quite bright patches of plage and some dark filamentous detail could be seen in both. Otherwise the sun is pretty quiet

If you are going to observe, rather than image, the alt-az mount is to be preferred over a (shaky) EQ-2 mount. Personally I would much prefer a table-top Dobson, like the Heritage 130P: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p2705_Skywatcher-Heritage-130P-FlexTube-Dobson---130-mm-Parabol-Optik---ab-6-J.html You get far more aperture, twice the light-gathering capacity, in a cheap, but decent mount. The slightly larger Heritage 150P is just over the maximum you list: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p12279_Skywatcher-Dobson-Telescope-Heritage-150P-Flextube---150-mm-Aperture.html To stay within budget, it is probably best to opt for the 130P, and spend a bit extra on some collimation tool.

That is lovely! Wonderful detail

That should be able to resolve the stars I would say. The fuzzy patch you described might be the cluster, which as I said can be a bit harder to pick up than expected due to the dense star field

Why not rotate the book 180 degrees? I find a RACI finder much easier to use than others

Had a quick look at the sun with my Coronado SolarMax-II 60 after lunch, and although the surface is fairly quiet, except for a bit of plage where the AR just turned the corner, and a small filament near the southern limb. I was pleased to see a nice prominence at the 7 o'clock position. Two smaller wave structures stood out from the limb, and just left of them a thin, slightly curved stream of plasma could be seen protruding from the disc. Well worth a look

What aperture are you using? In smaller scopes, it can appear as a fuzzy patch, rather than easily resolved stars. The fact that it lies in a very star-rich area of the milky way doesn't help either.

It's a fun cluster to watch, highly recommended

This is a wide-field image of the Flaming Star Nebula (IC 405) to the right, IC 410 and NGC 1893 beside it M38 is at the top with NGC 1907 below it. To the lower left we have M36, IC 417 and NGC 1931 are in the centre, and various Sharpless nebulae are top left (Sh2-231, 232, 233 and 235, I think). It's a crowded area

Couldn't resist fiddling with the HOO rendition, and using H-alpha as luminance channel I think I get a better result.

Cheers Dave, I think I will first get loads more data before experimenting with ways to combine the bands. There are many options in Gimp, Affinity Photo, and indeed APP itself to fiddle with the exact mixture, but I feel the S-II data are so bad you cannot really hope to mix them in meaningfully. Next time I will start grabbing O-III, before moonrise, then switch to a long session of S-II, and then, if time allows, also do extra H-alpha.

Yesterday was an unexpected clear(ish) night, so despite a full moon, occasional scudding hazy clouds, and later increasing haze and fog, I set up my latest wide-field imaging rig, consisting on my ASI183MM-Pro, combined with my Sigma 50-100 mm F/1.8 zoom, with a ZWO 5 position EFW, equipped with a Baader L filter, and three Baader F/2 narrow-band filters (H-alpha, O-III, and S-II), all on the old EQ3-2, tracked, not guided. I managed to get 30 120 s Subs in H-alpha and O-III, but only 9 in S-II, when fog scuppered any further attempts. I captured flats and dark flats in all three bands separately, and used a single master dark taken the day before (I just love set-point cooling, which is comparatively new to me). Using multi-channel stacking in APP processing the load automatically was really a breeze. Here are the individual channels after a little strecth in GIMP: H-alpha O-III S-II H-alpha is clearly best, with the best signal and least trouble with moonlight. O-III shows some nebulosity, much more starlight, and more problems with moonlight. S-II is worst, showing little signal (unsurprising with just 18 minutes of data and increasing fog). I did a quick combination of channels in GIMP, and HOO is not too bad: But SHO is problematic due to the lack of meaningful S-II data: Still, quite pleased with the results, as I learned that the performance of teh Sigma zoom at full aperture is very impressive. This is not unexpected given how it performed on NEOWISE last summer. The rig seems to work well, with my EFW being in action for the first time. The forecast for Monday and Tuesday night are pretty good, so fingers crossed I can get more data (especially S-II, and some O-III before moonrise)

S-II was cut short by fog, but still roughly 20 minutes caught, along with 60 minutes of H-alpha and O-III each. Enough to test drive the multi-band processing pipeline