michael.h.f.wilkinson

The telecentric Barlows from Siebert Optics now also ordered. They should arrive in 2-3 weeks (and then be held up in customs, no doubt)

Actually, make that 0.03 nm, rather than 3. But you are right, DSO narrow-band filters are useless for solar work.

With white light you should be able to see some granulation, and currently a pair of sunspots (checked this morning with Lunt 8x32 SUNoculars). More detail is only visible in ultra-narrowband H-alpha or Ca-K light. The image below shows the same sunspot in H-alpha, Ca-K and white light (from a few years back, when the sun was more active).

I personally like the 15x70 or 16x80 format more. They are far easier to mount (also on a monopod) stably. The wider FOV makes finding things easier too. The cheaper 15x70s are really 15x64 or so, due to internal baffling, etc, but they are still great fun. I had a pair for years before switching to a more expensive pair.

Bit the bullet and ordered the 152 mm F/5.9 version. It will probably arrive in September at the earliest. Just sent an enquiry to Siebert Optics to see when they can deliver a 2" 4.5x tele-centric Barlow.

Welcome to SGL, Mike

I will be live streaming the eclipse from work, but the forecast doesn't look good here either. I will still set up all the gear, just in case the weather changes

Nice work! Had a peek at these ARs yesterday, hopefully I can do so again during lunch

My wife knows I am insane. AP in this climate requires a masochistic streak, combined with a dose of OCD. However, if she complains about any new kit arriving I just start counting her shoes.

and whether they are unladen or are carrying a coconut

I thought everyone gnu the moon and sun are only about 5 times larger than the wingspan of your average pelican I do not know how that works out in swallows (African or European)

Lovely report. I love hunting planetaries, they are a highly diverse group of objects that often take a lot of magnification and survive moonlight if using a UHC or O-III filter. The brighter ones are about the only DSOs to show colour at the EP (the Saturn Nebula with Olly's 20" was a stunning blue green). Many really look like low surface brightness variants of Uranus and Neptune. One great weapon I have for the tiniest is the Denkmeier FIlter-Switch Diagonal, which allows you to slide a UHC or O-III filter in and out of the light path, causing the planetary to "blink" (actually, it is the stars that blink, and the planetary that stays roughly constant).

Had a look, and those images are very good indeed.

Thanks for that. The rotating focuser is a point for the TS/Technosky, and I don't need the finder or diagonal of the ES AR152, but then the case is a nice touch. EDIT: they don't seem to mention supplying a case for it any more. Choices, choices. I do think I am leaning towards the Technosky I can get in 2 weeks or so. Until the Siebert Optics 4.5x tele-centric arrives, I can always stop the scope down a little. It will still be a huge step up from the 75mm aperture I currently use for H-alpha. I might even get a 1.3x 1.25" tele-centric while I am at it, for use with C8 and ASI183MC and planetary/lunar imaging

I think the main use of a reducer in an SCT is actually for imaging, unless you are restricted to 1.25" EPs (as I was previously) and wanted a larger FOV. If something like a 24 mm 68 deg EP or a 32 mm Plössl already capture the entire image circle of the C5, there is not much use for a reducer, except for DSO imaging.

I have to agree that 2" EPs and focal reducers don't really go together on an SCT. Even on my C8, which has a considerably larger image circle than either the C5 or the C6, the use of the 0.63x reducer cuts the image circle to about 28 mm, so APS-C or 1.25" EP size. Anything with a wider image circle shows clear vignetting. Since I switched to a 2"visual back for the C8, I have used my reducer only for imaging.

I have just found a supplier that claims to be able to deliver a Technosky version with 2" focuser rather than the 2.5" in the TS version in two weeks. I think I will stick to my old Solar Spectrum filter, and get a Siebert Optics 4.5x or 5x Tele-Centric to compensate for the focal ratio.

OK, so here is a solar H-alpha mosaic made using Affinity Photo. This was a difficult data set, with lots of unevenness in the background due to problems with flats, and yet Affinity Photo has made a pretty decent mosaic. It isn't perfect, but a good result on very challenging data.

Just tested Affinity Photo on some difficult solar H-alpha data, and it did an excellent job. Still need to fiddle with it a bit , but it looks very promising

Just tested Hugin: no go for solar or lunar astronomy, as it doesn't like me entering a field of view smaller than 1 degree.

I think I might give hugin another try. It is a free stitching tool, that is apparently now mature

Typical! MS produces a good, solid app, and then they cancel it. It was just about their only product I liked. I don't think imerge supports full colour 16 bit per channel (48 bpp) images, which MS-ICE does. It was far less powerful and easy to use last time I tried

The ERF should take care of the heat, as it only transmits three bands around the H-alpha line, the solar continuum band, and the Ca-K line. The rest is reflected away. The focuser of the TS looks more solid than the ES, I must say.

I am about to pull the trigger on a relatively fast 6" refractor to use as a dedicated solar instrument. The idea is to place my Beloptik 85 mm Tri-Band ERF halfway down the tube, so by switching between Herschel wedge, Ca-K module, and my Baader TZ4 telecentric/Solar Spectrum H-alpha filter combo, I can image the sun in three wavelengths. There are two main contenders, the first being the TS 6" F/5.9 https://www.teleskop-express.de/shop/product_info.php/language/en/info/p2229_TS-Optics-RFT-152mm-f-5-9-Gro-feld-Refraktor-mit-2-5---Zahntriebauszug.html or any of its near identical twins. The second is the Explore Scientific AR 152, which is F/6.5 https://www.robtics.nl/nl/refractor-lens/5115-explore-scientific-ar152-air-spaced-doublet-ota.html The former has a very good rep with those using Quarks, and I am sure it would work fine in WL, and (perhaps stopped down a little) for Ca-K as well. I have two issues with this scope. The first is that being F/5.9, the Baader TZ-4 will extend this to F/23.4, which is a bit short of the minimum F/25 that the Solar Spectrum H-alpha filter likes. I can stop the scope down a little (as I currently do with my APM 80mm F/6), or could get myself a Quark (but have QC issues really been resolved?). The second issue is the long waiting time (110 days according to TS). By contrast, the ES AR152 is a bit of an unknown quantity. It gets good reviews, but not specifically for solar. It is considerably cheaper, and at F/6.5 it gets turned into an F/26 instrument, which is fine with the Solar Spectrum filter. Besides delivery would be expected in 3 weeks. Has anybody tried solar work with the ES AR-152? Is the 6" F/5.9 really that much better?

Can't go wrong with the Lunt wedge. I also have it, and I am not going to change that any time soon