Zermelo

Yes, the Altair. I have the same one - there's an unblackened retaining ring at the field end.

There is also an excellent BBC radio series, 13 minutes to the moon. From around episode 9 it covers the decent, including those 1201/1202 alarms). The same team went on to do further episodes about the Apollo 13 story.

Does it? I have the AZ-GTiX, I assumed they would be the same.

Yes, though actually it doesn't seem to need to be very tight to goto.

Of course, we're using the manufacturers' naming to define "range" here. As you say, some ranges consist of members that share the same qualitative design, differing only quantitatively to achieve the differing focal lengths. Other ranges show quite a bit of variation in design, begging the question as to whether they really are a family. I think I recall a schematic of the UFF series that showed quite a bit of design variation. There is presumably also a prize to be awarded for "eyepiece most out of line with the rest of its range". 😊

I think these ones are Celestron's badging of the UFFs? I have the 10mm, and it's very sharp.

... plus several more. I have the Altair version, which is optically the same, but made with steel, weighing a lot more.

I can think of one or two who might, based on previous posts about sets. In spite of having too many EPs, I don't have a set as yet. I was that sad kid you knew, who spent all his pocket money on football stickers, but never managed an entire team before the end of season. Actually, I'm going to contradict myself and claim a complete set of Sky-Watcher modified achromat stock EPs. The best is, if course, the 25mm.

I use a phone, but I have a tablet that I want to try out. Unfortunately SkySafari is currently having a hissy fit with Android 13, so awaiting a fix from devs. One feature that might be better on the tablet, when I get to use it, it's that there's a setting to dim the screen below the normal minimum brightness. It's in the accessibility settings, but I'm not sure if it's contained in that android version universally, or whether it's part of the Lenovo bake specifically.

No, you can move it in both axes, it's just that for azimuth there's no knob to slacken.

And in Android, if you've chosen to use gesture control for switching, you have an annoying white line at the bottom. As you say, night/red modes are available for both SynScan and SkySafari, though if you need to enter text, you are at the mercy of the keyboard, which won't follow the app setting. Skysafari has a built-in keyboard that you can redden, but I prefer SwiftKey for other reasons, and I've not yet found a suitable red theme to install for that.

Yes, I use it this way and it works very well for me. With iOS, I understand its possible to redden the screen in the operating system, which affects all running appa, and avoids the brightness during switch. I have Android, and it seems all that's possible there is to dim the screen to minimum and use the night light facility to take out the blue. So instead I've created a screen for my phone, by attaching a piece of red plastic to a gel phone case. In my Bortle 4 neighbourhood, it's rare that I find it too bright. Note also that SkySafari has its own slewing controls. There are only 4 speed levels instead of the 9 in Synscan, but most of the time you may find that you don't need to switch. I've gotten into the habit of switching every few minutes because, historically, Android killed off background processes if they weren't used. But I think I've stopped it from doing that. With Freedom Find, you slacken the alt clutch knob. It moves in azimuth if you just push it. You can use goto and manual slews in any sequence, though once you've used a manual slew, it can degrade subsequent gotos, because the second set of encoders is less accurate (because they're on the coarse side of the gearing).

Ah, then I mis-remembered. Thanks.

No, I'd not seen a non-collimatable version either, and I said so in a thread that I can't find now. Someone posted a picture of one, I have a feeling it was @vlaiv.

It's the same with the 127 - two versions. Yes, it reduces the cost of the bundle, but also reduces the weight, which will help with stability on a less robust mount and tripod.

The need for an oversized mirror to convey all the incident light into the image (and its absence in the Skymax 127) has been discussed before in several threads. Clearly, the loss of some light will result in a slightly dimmer image, and I believe that is the justification for the alternative 118mm, or whatever, that is quoted. But I'm interested to know (and someone will know) whether this shortfall has a corresponding diminution in resolving power. i.e. is the effect on this catadioptric system the same as stopping down a simple refractor to the same aperture? I'm interested because my Skymax has split half a dozen doubles at 0.9", and a couple at 0.8" that I'm 95% sure of. And I suspect it needs a slight re-collimation, too. The Dawes limit for 127mm is 0.91" and 118mm is 0.98". I believe a scope with a central obstruction would perform slightly worse than a frac. I know that the Dawes value derivation is empirical, and any individual assessment is a subjective judgement, but even so, the Skymax seems to be doing well.

A long session with the Mak this evening (in shorts). Planetaries M27 and NGC 6572, open clusters M29, M11, IC 4665 and IC 4756 (very nice), doubles HR 6981, HD 203358, d Serpentis and the Double Double, plus Saturn, Jupiter and the moon. Conditions were OK, though not as great as the forecasts had suggested. I may have been hampered by heat rising from the surrounding rooftops. The moon was very wobbly, even at lower mags. I did read that there was also likely some Saharan dust in the atmosphere down here in the SW. It was first light for my new Svbony 9-27mm zoom. I'll write something up elsewhere, but I was very happy with it.

The 127mm, as the others have said. And it is very compact, and easily carried with one hand.

As is well known, it started with a burger bar and finished with a restaurant. Or maybe: https://www.goodreads.com/quotes/781120-shh-said-ford-it-s-conical-so-what-you-do-is

Ah yes. Infinite existence, first causes, infinite chains of causes... Thomas Aquinas had a lot to say about all that but, sadly for this forum, it's very hard to disentangle Aquinas the philosopher from Aquinas the theologian. But as I said above, I suspect that at least part of our difficulty in coming to terms with this is down to our particular viewpoint within the thing that we're trying to explain.

I posted a heads up elsewhere about the current sale on these, and on the 7.2-21.5mm model (but I already have the OVL version of that one). Then I thought 🤔 ... Arrived in 5 days, £23 posted. I like the feel of it, very like my OVL (unsurprisingly), but the zoom ring isn't as stiff.

Just got in from a 2.5hr session with the Mak 127. It's been nearly three months since I was last out, due to health and other reasons, and it's scary how quickly you forget the routines that you used to do in autopilot. The moon near full was always going to restrict the session. I tried for M13 early on, and it was so poor that I stuck to doubles. At least the moon is quite low at the moment, and stayed behind the houses until quite late. Seeing seemed to vary from average to quite good, though anything beyond x250 was unusable, so the tighter doubles were inaccessible. Successes included Izar, HD 136160, Sarin, 100 Her, the Lyra double double, HR 7294, HR 7529, 49 Cyg, HR 8166, Gamma1 Del, Σ2725, HD 186902, Σ2789, and iota Cas. The last one was very unsteady, so I only managed two stars rather than the three I've seen in the past. But the real success of the evening was the Clicklock adapter I bought recently, this being its first outing. I love it. In most sessions I like to experiment with several different eyepieces on each target, and this gadget makes it so easy to switch. @badhex was right, I'm hopelessly hooked.

While I've been very happy with their products, I have noticed that Svbony's sales literature (or that of their resellers?) could do with a bit of expert subediting. Part of this is just less-than-perfect translation into English, but it seems that the graphic designers are sometimes given a bit too much freedom. There's another example that raised a smile, in that same zoom listing:

I haven't used one, but there was a recent thread discussing it: https://stargazerslounge.com/topic/411860-eyepiece-suggestions-for-turret

This evening's University Challenge had a question on interpretations of QM.