badhex

Thanks all. The slowest scope I have at the moment is an F10 C5, but my end game is to use my 0.965 EP collection with an old 0.965" Charles Frank newt I have in storage which is around F7.7. I knew when I purchased this particular EP that it would not perform well in that scope but as it was a CZJ I wanted to get it anyway as I think it was a good price. All of which bring me to my next question. If for example I have a decent quality Barlow - for the sake of argument, something that is nearly invisible to the optical train like a Televue - will the resulting slower FR of the scope improve the performance of a decent Huygens like this Zeiss? So let's say I use a 2.5x Barlow in my F7 TS102 bringing it up to an effective F17.5 - would the Huygens then perform accordingly, as if it were in a native F17.5 scope? If so, it would possibly be worth me adding the best 0.965" Barlow I can find (no Televues, of course!) to the collection as well. A 2x barlow would make my F7.7 newt F15.4, or a 2.5x would be F19.25.

Thanks! Will probably have to "make do" with my F10 C5 but will be interesting nonetheless!

Thanks Louis. I was struggling to understand the diagrams a bit tbh.

Thanks Don. Yes, had understood that it would need to be a slow scope to perform at its best, along with the narrow field of view. Not exactly sure what you meant by "not designed for chromatic correction" though. Meaning they display CA?

My vintage 0.965" collection grows! Carl Zeiss Jena 25mm Huygens 0.965". Have written a bit more in the EP section and will report there once I have had a proper chance to test it.

Hello all, My vintage 0.965" collection grows! Picked up a Carl Zeiss Jena 25mm Huygens from a German (non-astro) buy and sell site for what I think is a decent price (€50), and it arrived today. Looks to be in largely good condition for the age, well used and perhaps could do with a bit of a clean but otherwise sound. As far as I can tell, this version of the eyepiece is 1970s era according to a Japanese site which has pictures and details of the different CZJ EPs. Obviously would prefer it to be a ortho but not sure I'd get one that easily and certainly not for that price. I'll give it a clean up and see how it performs in a modern scope, and report back!

Oh BTW, mine also had old-seeming foam and IIRC the eyepiece itself was wrapped in some rubbishy thin plastic bag, not the resealable type we usually expect. That was also true of the TS version I think.

Excellent review Louis, and I would advise anyone to listen to your thorough reviews and testing over my finger in the air guesswork any day! TBH, I was comparing my possibly faulty memory of the 35mm + ZS73 from months earlier, I've been using the 35mm most recently with my TS102, so with no direct comparison it's likely just me misremembering performance. Funnily enough I recently did a quick daytime test of the 35mm and 40mm against a 30mm GSO and remember thinking that the 40mm was certainly not worse than the 35mm as I has suspected, at least in daytime. I was however focused more on the performance of the GSO (which was terrible).

Actually, I tried out my scopetech on my existing CF travel tripod ahead of my holiday later this year, and it didn't work out. I suspect because it's ~half a kilo more than the AZ-GTi and necessarily means a lot more touching the mount and therefore vibrations. That's what made me start down the Gitzo Traveller line of thinking!

Hello @Stu1smartcookie Not sure where you landed on this topic, but I managed to get round to checking the GSO 30mm against the 35mm and 40mm Paragon ED clones in My F5.9 ZS73, albeit in daytime. So both the GSO and Paragon clones show aberrations (astigmatism) in the outer edge, but it seems to be a lot worse in the GSO. I would estimate that only the very center 30% of the GSO is sharp, worsening significantly as you reach the edge. The Paragons seem to be sharp in the center 60-70%, and not as strongly affected in the outer 30-40% More disturbing (and obviously much more pronounced due to daytime viewing) is the lateral chromatic abberation in the GSO. I've included an image below which shows the extent to which the GSO shows this. As you can see, almost immediately out of the centre 20% of the field, strong red and blue fringing occurs, worsening significantly towards the edge. I tested this on a more distant object, a narrow metal chimney on a distant roof although I couldn't take a picture as the phone wouldn't focus correctly. I panned left to right to test both the focus and CA, and sure enough the CA was visible as soon as you start to move outside the inner 20% and was extremely disturbing at the outer 10%. Again this is visible to an extent in both the Paragons but to a much less disturbing degree. I would say visible colours were a much lighter violet, and again much further out to the edge than the GSO. Obviously, you should take this with a pinch of salt given that it is daytime viewing - this may be much less visible in at night and certainly I have not notice CA in the Paragons. That said, if funds allow I personally wouldn't recommend the GSO in a very fast scope given how it performs in my F5.9.

Haha sorry! It's true, there is always something else on the list 🙂

Thanks, good to know. I think the Series 2 which I'm looking at is a bit bigger that the Series 0, but not a drastic difference in payload (12kg vs 10kg). I already have a small CF tripod for travelling which I use with an AZ-GTi and ZS73. It's okay, but owning the Gitzo 5 has kinda spoilt it for me. The Gitzo 5 has been worth absolutely every penny, but obviously too big for travelling really.

How do you find the Gitzo traveller - and is it Version 1 or 2? Seems like it aholds the 76DC pretty well, how about at higher powers? I have a Gitzo 5 and it's incredible, so strongly considering the traveller as an airline friendly option.

I forgot to add that I have the Superview 30mm also. I have not tried it directly head-to-head against the Paragon/Aero EDs but I wasn't a big fan of this EP - I much prefer the 35mm Paragon. Maybe I'll dig it out and try them head to head in my ZS73.

I have both the 35mm TS-Optics version and the 40mm Lacerta version of the Paragon/Aero ED clones - although AFAIK technically the 35mm was not part of the original TMB designed lineup. It seems to be a 'new' EP built by KUO with the same design as the 30mm and 40mm. The 35mm has had the most use and I really like it as a widefield search and survey EP. I only got the 40mm a couple of months ago, so I cannot say definitively which is 'better' but the 35mm definitely seems to perform better in my F5.9 ZS73 than the 40mm. Both have some astigmatism in the outer ~20% but I don't think this is enough to discount them considering the price (after all, a 41mm Panoptic is at least 4x the cost of the 40mm Paragon!). If you're looking at 30mm, I would probably strongly consider the APM (et al.) UFF over the Aeros. I have the 24mm UFF, and assuming that the quality of the 30mm is to the same standard - which most seem to say it is - then it's almost certainly going to be better than the Paragon clones.

Just another thought, I just re-read what I wrote and it might have come across that I'm saying it's not worth bothering; for avoidance of doubt, what I actually meant to infer was that the overall outcome of the testing link comes to no specific recommendation of one solution over another, and that I'm inclined to believe his general outcomes as he seems to have done a very good job collecting evidence.

Okay, a bunch of links. Rear baffle/port opening sizes, and some tips on 2" EPs according to Celestron: https://www.celestron.com/blogs/knowledgebase/i-want-to-use-2-in-eyepieces-with-my-sct-and-or-mak-will-there-be-vignetting-from-the-ota-itself An in depth look at using 2" accessories with a C5, with practical testing, measurements, photos etc. Note that although this is for the C5, the rear baffle size very similar in a C6 (27mm) vs either 27mm or 25mm for the C5 depending whether you listen to celestron or real world measurements: http://www.waloszek.de/astro_ce_c5_2z_e.php There also a bunch of other stuff about adding finder shoes and other bits. There's a key takeaway from the above which may be of interest, namely whether using 2" provides any benefit over using the reducer + a max field 1.25" EP: Obviously this is one person's experience but I felt that it was quite well documented and tested, and so am inclined to believe the findings.

I have the Aero 35mm and I really like it. I picked up the 40mm as well after a long search but it definitely doesn't perform as well in shorter FL, although at F8 neither should really be a problem. Both suffer from aberrations in the outer ~20% (depending on FR) , but are great for search and survey type usage or just taking in large fields. And they are pretty reasonably priced. I think the biggest issue is the small size of the rear baffle in the C6, which would necessarily mean some vignetting. I found a site where someone did some experiments with 2" EPs, I'll see if I can dig it out.

A replacement TS 2" diagonal arrived Friday, and my copy of Discovering Deep Sky Objects arrived today! Looking forward to using them both 🙂

Bit late with this one but on Thursday after a week of thinking about it I quit my job as it has not been good for my mental health/anxiety or stress levels. The same night it happened to also be fortuitously clear, so I popped out for an hour or two to observe and also reflect (although I was using a 102mm frac - I suppose the diagonal counts 😂) M12 which was somewhat surprising considering I couldn't get it in Bortle 4 week or two ago. Some thin clouds turned up, moving me further West. M3 was a little unimpressive, but I can't work out if this is just a product of thin clouds or being back in LP skies after a week in the countryside. Saturn was on the rise so I moved completely away from the potential clouds. Technically the second observation with this scope but the first was early morning and not dark enough to truly enjoy. Swimming a bit in haze over the rooftops but still a lovely sight. Couldn't make out the Cassini division. Jupiter too low down, so carried on with Saturn for a while until Jupiter was better placed. NEB and SEB now very clear, in lucky moments in the shimmer. Galilean moons hung like tiny coloured pin heads, thanks to the atmosphere. I swapped between 71x and 159x, with more moments of clarity at 71x but more discernable detail at 159x due to darkening. Probably should have Barlowed my 17.5mm Morpheus to get 103x but didn't really fancy faffing about. No discernable GRS. I can't wait for Jupiter to be higher in the sky later this year, the fleeting moments of clarity were wonderful in this scope. It got light so time for bed, but just before finishing I spied Mars just above the horizon. As expected, a tiny red misshapen blob!

Welcome back Jake!

Just coming back to this, in the end TS replaced the whole diagonal. I sent it last Thursday, and after a few email back and forth I received the replacement today. Fingers crossed this one doesn't have the same issues, although I will definitely try to pick up new steel thumbscrews just in case!

Genuine question that is difficult to phrase without sounding controversial: On public outreach and awareness, how many people having seen something from an eVscope would be likely to actually get interested in astronomy, especially given the (current) cost of such scopes and the, let's sadly face it, somewhat less impressive visual views from a standard scope? Does that even matter?

I had forgotten I'd posted this! I actually solved it with TS-Optics handle I managed to miss the first time round (not hard on their site, it was filed under some obscure category). You can see it on this picture - it's loads easier now to mount/unmount or adjust balance.

Good sleuthing, bit surprised that a company known for high quality gear like Long Perng would have come up with a design that has such restrictions, but there you go. I may have said earlier in this thread but the 1.25" version of this is basically the same but scaled down, and therefore has the same potential for vignetting issues. Can we assume then that Long Perng made those as well?