John

Fair point of course but I will never forget the thrill of seeing the spiral structure and "bridge" of M51 with a 12 inch dob (not mine) and my own eye at my first SGL star party in Herefordshire 🙂 Stuff like that stays with you 😁

The irony there is that it is often later in life that one can afford good quality equipment with high potential performance. I quite often wonder what I would have been able to achieve if I could have afforded the equipment that I have now back in my 20's 🙄 Back then though full time work plus bringing up children would have left me too exhausted to take advantage of it so probably no overall gain then !

Thanks Louis - that sounds a good suggestion.

No problem if that can be done. I don't want to distract from your original thread 🙂

I've seen spiral structure in M51 from my bortle 5 back garden with a 10 inch aperture on a dark night of good transparency. Not really "in your face" but it was there when my eye had adjusted and I had become fully dark adapted and I used some averted vision techniques. Subtle to be honest with you. I observed the same target with a 20 inch aperture from a darkish site a few years back and the view was like the images you see - wow !!! It is difficult to guarantee what aperture will do this because observing conditions, observer experience and other factors have quite a bearing on what can actually be seen. Some observers have seen spiral structure with as little as 4 inches of aperture but not me, alas 🙄

Would you not still have to pay import taxes though ?

One thing that I can share is that, for me, the APM 7.7-15.4mm zoom has to be treated as a 2 inch eyepiece. Used in 1.25 inch mode it needs such a lot of inwards focuser movement that it will not reach focus at all in 2 of my scopes and only barely in the others. Used in 2 inch mode the APM zoom reaches focus at around the same position as the Delos 14mm. Because I currently use refractors, I need to ensure that the 1.25 portion of the APM zoom's barrel clears the diagonal mirror when used in 2 inch mode. This has worked out OK in my Astro Physics and Tele Vue 2 inch diagonals. If I was to use a filter on the eyepiece barrel I think there might be problems though so any filtering of this eyepiece will be applied at the end of the diagonal barrel.

I do have a clone of the Hyperflex 7.2mm - 21.5mm zoom. I'm not sure how close that is to the SvBony 7-21 zoom ?

Thanks for the interest. I learned a long time ago not to jump to any conclusions when comparing optical equipment. I need to have several decent sessions using the eyepieces on a variety of targets with scopes of different specifications. Due to the weather conditions I have managed just two short sessions under mediocre conditions which told me very little about the comparative merits of these zooms I'm afraid. I'm very glad that I don't review equipment like this for magazines where there are deadlines to be met. It must be very difficult to gather enough experience to compose something useful with the current UK conditions🙄

I think there should be longish thin bolts with wingnuts on them through those holes in the upper leg sections just above the top of the lower leg sections. These bolts go through those "loops" in the metal tray supports and secure it as well as enabling the tripod legs to push against the supports creating tension and rigidity. Any DIY shop will probably carry them.

That is an excellent price. Does that include import tax / duty or does that not apply to Japan - France imports ?

It started before AI became so accessible 😁

Could it be that the losmandy bar is on the bottom of the tube rings ? (sorry you are feeling unwell and apologies if you have already looked at the other side of the scope) Edit: I realise now that you must have checked this so please ignore my suggestion 🙄

This group test by Bill Paolini is quite often posted but it is relevant so here it is again if you have not seen it: Mirror vs. Dielectric vs. Prism Diagonal Comparison - Articles - Articles - Articles - Cloudy Nights It also highlights the importance of effective baffling / blackening within the diagonal body.

I suspect this will turn out to be more of a "why I love binoviewing" thread than in any way dissuade you from doing it 🙂 It may highlight where the technique has the most, and least, benefits so that might be useful 👍

I've tried binoviewing quite a few times over the years with my scopes. I just didn't get on with them. I got the images to merge OK but I'm just more comfortable observing with the one eye. Also, my eyepiece tastes are for hyper-wides and super-wides such as Ethos and Pentax XW's so it would get expensive to have to double up on those. I'm not a huge user of binoculars for astronomy generally actually although I do have some nice 11x70's. Shame really because I read quite a lot about how many folks do find binoviewing extremely rewarding. It's just not for me, alas 😔 This is the last time I tried it - my 130mm triplet with William Optics binoviewers which FLO loaned me with another scope:

I use the Baader 1.25 inch twist lock adapter with my Baader T2 prism and it works exceptionally well I feel. No snagging on eyepiece undercuts because of it's longitudinal nylon tension rods.

We can work as a team Don - you handle points 1 - 21 and I'll contribute the "other comments" 😁

I do use a Baader T2 prism diagonal in 1.25 inch mode my F/9 100mm refractor and it works well but I use 2 inch diagonals (AP and TV) with my other refractors even though I mostly use 1.25 inch eyepieces with them. Quite a few of my eyepieces are on the large side so the security of the 2 inch format diagonals is good to have I feel. The TV's are made from a single block of alloy which seems particularly robust and secure.

Towards the end of August for a possible improvement ?: UK weather: When will it stop raining and the summer improve? - BBC News

Look at where the eyepiece sits in Suiters "wobbly stack" of factors that impact the quality of the view - way down the list. How could any image indicating possible eyepiece sharpness take account of all the other things, external to the eyepiece, that will impact that ? It would be a nightmare for vendors as well - so many returns when observers views are not quite what the advertised image fidelity seemed to promise. I agree that consistently accurate information on eyepiece specifications would be good though. So often AFoV and actual eye relief figures (even focal length occasionally) are inaccurate and field stop diameters are often missing altogether. Anyway, this is straying off the topic of the new Takahashi eyepieces so I'll leave it there and wait for some reports from those who are actually using them under the stars. There are some starting to filter through on the CN forum.

The "standard" for eyepiece performance has to be how they perform for their intended purpose, with a human at one side and a telescope at the other, observing celestial targets, surely ? Other data is of interest of course and fuels discussion during unfavourable conditions but the practical experience must have primacy I feel. Otherwise forums like this will become little more than technical / theoretical interest discussion groups which might appeal to a few but I suspect the majority would much rather be out there "doing it" as often as possible.

Given the weather we have had in the UK lately, practical testing of eyepieces under the stars is getting rather hard to carry out. I have a couple of very interesting eyepieces on loan currently and but it is clearly going to be a long time until I get enough practical experience with them under my belt to write anything meaningful about them on SGL 🤔 With optical standards edging closer and closer between the best and the rest, you need some sessions under good conditions to spot the often subtle but consistent differences between them. Its getting a bit academic as to whether eyepiece X has a tiny % better light scatter, sharpness or contrast than eyepiece Y if the chances of using the darn things at all is so slim 🙄

Same here 40 odd miles south of you 😒 Sigh .... another evening tweaking my backlash 🙄