John

This thread has more mentions of Tasco than any I've seen on SGL for many years !

This was the set that I had about 12 years ago and very fond of them I was too !:

I hope it does not go back to what it was in the 1970's / 1980's. Equipment choice was quite limited back then (in the UK at least) and the prices seemed really high for someone (me !) trying to get some modestly decent equipment on a tight budget

I do agree that seeing all those fine scopes not being used was slightly sad, the row of Pentax apochromats just sat on the floor, especially

Hello and welcome to the forum. Looking at the position of the moon a couple of days ago (I've taken the 22nd as it was clear night) I would say that the group of stars you saw were likely to be the Pleiades or 7 Sisters star cluster which is in the constellation of Taurus. Despite the name, 6 stars are more regularly visible to the naked eye and they do form a close group with a shape that could approximate what you describe. They would have been to the right and slightly higher in the sky than the moon that night and in the south eastern sky.

I've used my H-Beta (Astronomik) on M42 with some interesting results I really is worth experimenting with different filters on different targets and deviating from the established advice - sometimes you get a nice surprise ! FWIW these are the figures for my Lumicon O-III:

Very nice Dave I use one of those on my Tak FC100.

I think these are a new range - I've not seen much about them reported as yet. For that sort of money I'd probably prefer a Tele Vue Delite or a Pentax XW 7mm both being well known and very well regarded eyepieces. I had an ES 82 (non-LER) 4.7mm recently which was pretty good but that cost £75 (used).

That's interesting. For me, the O-III usually does a noticeably better job of enhancing the contrast of the Owl than a UHC does.

I've quite recently acquired an 8 inch Orion Optics Europa and found the cool down times rather lengthy in it's standard form. I may change the primary cell to OO's current and more open design but meanwhile I've ventilated the back plate (photo below) which does seem to have helped. A fan, such as the ones mentioned in this thread, may well be my next step I think, before shelling out £200+ on an OO upgraded primary cell.

Jupiter through thin cloud this evening with my 100mm refractor at 180x. Quite nice feature contrast, GRS on the other side though. Callisto and Ganymede are close to each other in the sky and the difference in the apparent diameter of their disks is quite obvious visually. Probably all the observing I'll get looking at the rest of the sky but every little helps

If the Veil nebula is still placed OK for you, the difference between these filters on that target will make an interesting comparison. If the Veil is not in a good place, the Owl Nebula (M 97) ) in Ursa Major is also another interesting "test" target for these narrowband and line filters.

This is an article about the Telescope Museum in Tawa, Japan. Some wonderful telescopes in there but very few Takahashis, as far as I can see: https://www.cloudynights.com/articles/cat/articles/a-visit-to-the-museum-of-astronomical-telescope-r3040

A UHC or O-III filter might actually let you see something of some nebulae that you can't see anything of currently. They work better still under dark skies of course.

Have the optics of the SW 100ED and the Starfield 102 actually been compared directly yet ?

UHC followed as rapidly as possible by an O-III Astronomik is a good brand to aim for.

The first proper astronomical telescope that I looked through was an old 8.5 inch newtonian in 1971-72 which was in my school observatory. Back then, all I had access to myself was my parents Prinz (Dixons) 8x30 binoculars. I did manage to see and sketch a comet with them though. The first telescope that I actually owned myself was much more modest - this 1960's Tasco 60mm refractor, which I still have in it's wooden case: My 2nd telescope was a bit more serious - an Astro Systems (Bedford) 6 inch F/6 newtonian on a Fullerscopes equatorial mount. I observed Halleys Comet in 1986 with this instrument: Since then ? ........ er, I've sort of lost count

I've tried my Skywatcher ED120 stopped down using the central hole in the dust cap which turns it into a 52mm F/17.3 ED doublet refractor. I was doing this for fun really, just to see what could be seen with such a small aperture I've also done it using a cardboard mask with an off axis aperture with my 12 inch dobsonian and I can get a 110mm unobstructed aperture with an effective focal ratio of F/14.4. The performance of that seemed just as an apochromatic refractor of 110mm would perform, perhaps unsurprisingly.

Stellarium shows Himalia. It is a lot further away from Jupiter than the Galilean moons though (which are clustered close to the planet at this level of zoom):

That will work and will reduce the CA visible considerably. It will also reduce the effective aperture of the scope to the diameter of the hole in the dust cap and therefore the resolution and light grasp will reduce as well.

I have an old Philips one somewhere. I've not used it for many years though.

This chart sets out the levels of CA that you can expect from achromat refractors. The relative differences between different spec scopes are reasonably accurate from my experience: Quality achromat refractors such as the Scopetechs should also have minimal amounts of spherical aberration (SA) which means sharper views and better handling of high magnifications.

Although the seeing was quite good last night and the primary star well defined I could not get any indications of Dubhe B with my ED120 refractor last night even at 300x plus. Theta Aurigae A & B on the other hand (and a much easier pair) was beautifully split by the scope at 300x. The 2 fainter and further off stars in the group showed well too.

Just to give an idea of the scale of a big, long refractor, this is the 150mm F/12 optical tube that I posted earlier in this thread alongside a 120mm F/7.5 and a 102mm F/6.5:

I forgot that I still have this one ! F/13.3 60mm - my 1960's Tasco achromat on it's rather wobbly alt-azimuth mount and with .965 eyepieces ! Optically its actually very nice scope My old TAL 100 RT was a nice scope, but at F/10, possibly a little short for this thread ?: This is currently my longest refractor. 130mm F/9.2 triplet apochromat: