Hans Joakim

Sure thing! The 75 is a wonderful design, and light enough so it can be carried out with the tripod in one piece. If I had to let one of them go, I would probably hang on to the 75 since it gives practically nothing up to the 100, except the slo-mo controls and option for motors. The Vixen clamp can accept the counterweight shaft, so you don't really need the flange for this purpose.

Hi Daniel, I can definitely recommend the AZ75 as a light-weight and portable alternative to AZ100. I have both, and use them with a TSA-120 on a Berlebach UNI-28 tripod. There is no discernible difference between the mounts in terms of stability in my experience. My experience is also similar to yours concerning the slo-mo of the AZ100.

New Willmann-Bell additions to my astro library. The Uranometria volumes are the 1987-1988 versions, in perfect conditions, and were acquired from a fellow SGLer. Thanks again for passing them on, it was a pleasure doing business with you! Can’t wait to use them. Also looking forward to reading up on telescope designs and about orbital calculations in analogue times.

Aha! https://alternativedistribution.com.au/product/fluorite-water-bottle/ Jeremy has had his spiritual detox it seems!

It fits the AZ100 base, so 65 mm diameter!

Try this: https://www-dark--star-it.translate.goog/astronomia-articoli-e-test/test-strumentali/takahashi-tsa102-e-fs-128/?_x_tr_sl=it&_x_tr_tl=en&_x_tr_hl=no&_x_tr_pto=wapp

A very nice comparison of TSA-102 and FS-128 as well, from 2008 but still very much in line with the discussion in the current thread here on SGL: https://www.dark-star.it/astronomia-articoli-e-test/test-strumentali/takahashi-tsa102-e-fs-128/

Anyone using the XW 85 with Dioptrx? Curious to hear if the resulting eye relief feel comfortable!

Yes, I believe these are all the same United Optics (Kunming) 4” F/7 doublet design (lanthanum and FPL-53): http://www.united-optics.com/products/telescope_326922/telescope.html.

Looking great! The AZ75 will be a terrific mount for these scopes! You'll probably want to turn the scopes so you have the clutches facing you when observing 😇

🤑😻 Funny how things change! As a young teenager, one would pour over glossy magazines with photos of minimally dressed models. As an old, sad sack, I now spend most of my free time devouring catalogues of Japanese telescopes. I wonder what that young teenager-me would think of me now. What is this catalogue, Jeremy? I need it bad! Seems different from the most recent one over at Tak Japan: https://www.takahashijapan.com/ct-products/new-catalog/202310_Catalog_web.pdf

That’s my thinking too, Mike. Keeping the scopes in your shed also means small temperature differences and the scope will quickly equilibrate to outdoor temperature. If the scope needs to be brought into the house after a session out in the cold, I will bring the telescope soft case out as well, during observation time. At the end of the session, I cap the scope, place it in the cold bag, and bring that in to slowly heat up indoors. In the morning, I take the scope out of the bag and uncap it. I am not sure if this last step is really necessary, as I have never had issues with dew or moisture on the lens the next day. Best thing as I see it, however, is to have a shed where the scope can live. That way we spend daytime apart, and enjoy each others company during the night.

Thanks for sharing, @josefk! I will also be looking for a case for the AZ100 w/ 200 mm riser, but with the 125 mm Tak cradle for the TSA-120. I do have one of the Tenba Cineluxe “doctors case” for my AZ75 - I think it is the Cineluxe 21. That works perfectly for the smaller, shorter mount, and allows it to be safely stored with the cradle mounted. The AZ100 is taller, and the riser complicates the storage - perhaps the way to go is to separate the riser (leave the riser top fixed to the mount). I will start looking in earnest when it is all here and assembled, and certainly share if something useful comes up! Thanks again 👍

@josefk Loving your TOA on the AZ100, so hope it is ok to revive this thread! Just curious to know whether you have found a good case (soft or hard) for the AZ100 with the Tak cradle fixed? Or do you remove the cradle from the mount every time you tear down?

Quasi-stationary Rossby waves, anyone?

These Oklop “Styropacks” are pretty neat. I have one for my GEM45 mount that makes carrying and transportation much easier. Great looking scope too!

Hi Josef, I haven’t yet tried the 1.5x ED, but I have used the 1.6x TKA36595 quite a lot. At least that extender leaves the focus position nearly unchanged.

Late to the party, but still: Heres a nice solution for the Berlebachs out there:

Absolutely fascinating, for sure! I was first introduced to GR as part of a course in classical field theory way back when, but for me the physics remained obscured beneath all the index algebra and Christoffel symbols. The astronomy hobby has rekindled my interest in GR in a major way, and I picked up Sean Carrolls introductory book last year (https://www.amazon.co.uk/Spacetime-Geometry-Introduction-General-Relativity/dp/1108488390/ref=sr_1_1?crid=1W91PXBQ3JB0P&keywords=sean+carroll+general+relativity&qid=1691008661&sprefix=Carroll+genera%2Caps%2C114&sr=8-1), which I think is great and an easier read than what we had! I’ve also been following these lecture recordings, based on the same book (the whole lecture series is up on YouTube): It is a bit unfortunate that the two most successful theories of the universe, GR and quantum mechanics, are largely confined to advanced students… it is the way it has to be, I guess, as it doesn’t make much sense to introduce Lorentz invariance or Heisenbergs uncertainty principle to most 12 year olds. Edit: By the way, a nice note on the relativistic correction to the perihelion shift of Mercury: https://www.math.toronto.edu/~colliand/426_03/Papers03/C_Pollock.pdf

Same here, no pic as I don't have an FS128, but would like to recommend bolting the Tak cradle to a Vixen or Losmandy dovetail with M8 35 mm hole pattern. I have done this for my FC100 and TSA120, and use the DP75 Losmandy-style dovetail by K-Astec for mounting these scopes to an iOptron GEM45. These dovetails can be had in 152 mm, 222 mm, 257 mm or 292 mm lengths, and all have "Tak standard" bolt patterns - see e.g. 222 mm plate here: https://www.kyoei-osaka.jp/SHOP/k-astec-dp75-222.html. Lightweight and fantastic quality.

In this (very nice) Japanese video, it is suggested that the short drawtube travel is to ensure rigidity of the focus and avoid bending of the drawtube when attaching heavy cameras: https://youtu.be/fv0ewiHee8U?t=540 The link starts the video at the relevant point, but the whole thing is a very nice to watch. There's also an excellent video on the 100DF: https://youtu.be/xl1V7Ii2bsU (now with both Japanese and English audio - very impressive!). I found a 40 mm extension tube to be helpful for achieving focus when using the Baader 2" BBHS prism in my DF (top scope in photo, with M68 extension tube):

Thanks @josefk! Much appreciated. This riser solution looks terrific. It's Rowan, so of course it is great. Very practical, as one can have the main riser element permanently attached to the Berlebach tripod head, and the top riser plate attached to the AZ. I'll be ordering one of these!

Stupid question perhaps, but here goes: Has anyone used one of the AZ100 pier risers with the AZ75? Judging from the schematics over at Rowan, it seems like these risers are fully compatible with the AZ75. It would be nice to have some extra distance to the tripod legs when observing with a front-heavy scope. Thanks!

8 - the Pentax XWs (70 degree AFOV)! Got the two grenades (30 and 40 mm) last, but find myself using them the most. Awesome for scanning the sky. The XW eye relief is also good for a glass wearer like myself.

An excellent complementary book (one for your better half perhaps?) is the NASA Archives by Taschen - a lovely coffee table thing with interesting essays along with non-remastered photos. Currently 25% off at Amazon, and with a smaller version at only GBP25 due 5 January, it seems.