John

I managed to get Triton again with the 130mm tonight:

Just managed to get Neptune's moon Triton with the 130. Rather pleased with that - it's mag 13.4 dimmed to 13.7 by atmospheric extinction according to Stellarium but the limit for 130mm aperture seems to be 13.4 according to the calculators I've no doubts that I've picked up Triton visually and it's position corresponds with Stellarium and Cartes du Ciel. Needed lots of magnification - 400x and even 600x used (crazy !!!). Perhaps Stellarium's estimate of dimming is too pessimistic ? Anyway, nice to spot Triton with the 5.1 inch scope

Just an additional note on this. The Oval BA used to be a red coloured storm system, maybe the one sometimes called "Red Spot Jr" ?. It has changed it's colour over the past few years becoming pale / whitish recently. This has attracted the attention of researchers who are trying to work out the reasons for a "Temporal Evolution" of this systems colour.

Excellent seeing conditions tonight enabling my 130mm refractor to tease out some pale oval features in the planets South Temperate Belt. One has been called the Oval BA by regular observers. I can see 3/4 others around it at 240x. Quite hard to spot but they pop into view when the seeing is at it's steadiest. A couple of nice barges along the north edge of the North Equatorial Belt as well. These image from Sky & Telescope back in August shows these pale oval features (and barges) along with moon transits happening at that time:

Good seeing tonight though, isn't it ?

Not something I do but valuable for those that want to ! Joking apart, are these single product threads really beneficial for the forum as a whole ? There are a number of things discussed in this thread that would have application and relevance to many mounts but I suspect it only really attracts AZ100 owners or prospective owners. Just a thought ! Back out to Saturn and Jupiter with the LZOS 130 / 9.2 now. 300x - 350x is holding up very well so the conditions are top notch Pi Aquilae was very interesting at 600x earlier

Just like the T-Rex then

This relates to my T-Rex mount rather than the AZ100 but I was somewhat surprised to find that the GMT 128 (basically an EQ6) tripod was less prone to vibrations than the UNI 28 when I compared them both recently. So when I post pics of my TMB/LZOS 130 F/9.2 on the mount, you will see the steel GMT 128 tripod under it rather than my nice wooden Berlebach UNI 28. Having invested in a new EQ6 head for the UNI 28 I was a little disappointed in this result to be honest but there was no mistaking the tripod that fared better with the T-Rex. Sorry to introduce a non-Rowan mount but the thread had veered to tripods so I thought it was relevant. My BB UNI 28 is still a great tripod to use with my Skytee II and Giro Ercole mounts of course. As the T-Rex + GMT 128 does such a good job with the 130mm F/9.2 triplet (< 1 second vibration damp time), I don't feel the need for a BB Planet. I do try and keep the weight of my setups to a reasonable level as well - I like to be able to move the whole rig around the garden as needed.

I have seen Triton with my 130mm refractor on a couple of occasions when the transparency was good and it's elongation from Neptune favourable. It's relatively straightforward now with my 12 inch dob. I've found the Uranian moons slightly harder - I've only managed to see 2 of the 4 that are theoretically visible with my 12 inch.

It's not really a cheat sheet and takes a little reading but this article is an often linked and excellent resource: https://www.prairieastronomyclub.org/filter-performance-comparisons-for-some-common-nebulae/

Some consolation for my cloud cover then - sounds like the seeing would have been poor anyway ! I've just bought my setup in as well

Solid cloud now about 12 miles SW of you - I can see the Bristol "glow" reflecting off the bottom of it. Good for you if you have found a gap !

Thanks - we did have a " show us your lickable glass" thread at one point but I've tended to resist that temptation

The opposite applies here, currently. My 130 is still out but under rather heavy and unbroken cloud cover

It was clear when I set my scope up an hour ago but that cloudy stuff has crossed the Severn from Cardiff and is now covering my sky

TMB/LZOS 130 F/9.2 triplet cooling on the T-Rex mount:

In my opinion, the O-III is excellent when used on the Owl Nebula of these. For the others I tend to prefer a UHC or no filter at all if the sky is reasonably dark. Messier 27, The Dumbbell Nebula in Vulpecula is another where a UHC can produce very pleasing results. Plus, it's a big planetary nebula compared with the others ! The bright globular cluster Messier 15 in Pegasus is worth a look as well. Coloured double stars such as Albireo and Gamma Andromeda can impress too ! Oh, and the triple star Iota Cassiopeia is well worth a visit.

Looks promising here until around midnight at least so I will get a scope out tonight. Probably the 130mm refractor again.

I'd go with the TEC 140 as well. No disrespect at all to the TSA 120 of course.

Often these multiple element systems have the lenses arranged in more than one group, so you can find a doublet or a triplet set much closer to the focuser of the scope. The TAL Apolar 125mm had 6 elements with just a singlet as the furthest forward and no low dispersion glass types used. It was pretty much apochromatic as I recall. I would not want to have to collimate one though ! Point 7 above is the focal plane, not a further element.

Great stuff Looks like I picked the wrong night to take a break from observing

That alone is usually enough to put me off using a piece of kit, unless it's capable of providing massive benefits. I really don't like any additional complexity / faffing

Funny how these threads on forums often seem to turn into a "why I'm not keen on Tele Vue" thread Doesn't seem to happen with, say, Takahashi threads though Hey ho

I do see the effects of AD from time to time since the planets have been lower but never to the extent of feeling that I ought to be using an ADC. If others find one useful / beneficial, that's great so I'm not in the "against" camp, I just don't feel the need to use one myself Similarly with a coma corrector for my 12 inch F/5.3 dobsonian. It's good that these devices have been developed and are available for those who wish to use them though