Louis D

I found the 12mm to be the best of the Starguider BSTs. The 15mm was only marginally better than the 18mm. Read my critic of each eyepiece in a comparative shootout:

Is this what you're looking for?

I would take a 24mm to 32mm widest field eyepiece along to supplement the zoom. If your scope can handle the power, a shorty Barlow might pair nicely with the zoom to get to higher powers.

Is that a circle-V maker mark for Vixen I spy on the Celestron? Vixen sure did make a lot of really good eyepieces back in the day.

So true. The Celestron Luminos and Meade MWA lines never really recovered from poor reports by early adopters. MWAs were discontinued after just a few years. On the other hand, everyone praises the 17.5mm Morpheus even after a 3 year wait for it. If early adopters report that eye relief works for eyeglass wearers and the quality of the image is a good step up from the BHZ, I'll probably get one of these new zooms.

I really like the 20mm version in my Barlowed binoviewer, but it isn't very good at f/6. How is the exit pupil behavior of the 6mm? I've read that the 6mm and 9mm versions suffer from kidney beaning (SAEP) which requires careful eye placement.

So, the 22mm LVW could conceivably be similar to a Panoptic design (4 groups, 6 elements): I wonder if anyone ever did a shootout between it and the 22mm Panoptic. 🤔

See inline comments above.

Labor and overhead costs are very low in China compared to the US and Europe.

Which, the 42mm? The rest are 7 or 8 element negative/positive designs as far as I can recollect. The only non-Nagler patent cited by Al in that patent application was for the Scidmore. I thought he might have cited the Wild design, but he didn't.

The Wild design is reminiscent of the Panoptic design:

It is curious Chinese made ED and APO scopes usually use Ohara or Shott glass. You'd think China would have mastered making optical glass by now.

When held up to a bright, white background with extraneous light blocked between it and your eye to keep reflections at bay, I would think the OIII would appear blue-green, the HA would be deep red, and the SII would appear super deep red, almost black because it's approaching the limit of human eyesight.

Ernest over on CN posited in this post that the following apparent fields of view (AFOVs) in degrees will not show coma at the following f-ratios (simply square the f-ratio): F4 - 16 F5 - 25 F6 - 36 (classic ortho will have whole thir FOV free from coma) F7 - 49 (super plossl are coma free in F7 Newton) F8 - 64 (WA eyepieces are coma-free in F8 Newton) F9 - 81 (even Naglers are coma free in F9 Newton!) Thus, at f/4, you're looking at a coma free field with a 16 degree AFOV eyepiece. Those Morpheus and Panoptics, being well corrected to the edge at f/4, would show coma at f/4. I know I observed for about 15 years without using a CC because I didn't notice it, it having always been there. However, I started upgrading and widening my eyepieces about a decade ago and started noticing the coma and decided to get a used GSO CC for $75 to try out. It was an amazing difference. I didn't think I'd notice, but it was quite obvious to my eye at least when the CC is in or not in use even at f/6.

You'll definitely notice an improvement with both the Morpheus and Panoptic eyepieces. For the GSO CC, I add a 25mm spacer ring between the eyepiece holder and the optical nose piece to get to the 75mm separation sweet spot with a 1.25" adapter typically adding another 5mm of separation. The CC designer has stated elsewhere that 5mm on either side of the design separation is almost indistinguishable visually. I've found that to be true. Eyepieces that focus within 5mm of their shoulder (reference plane) don't show enough improvement to bother with parfocalization. However, I had to parfocalize my 12mm NT4 with five 4mm thick O-rings because it focuses 20mm below the shoulder which led to noticeable uncorrected coma. So little 2" barrel was left that I had to add a 20mm M48 spacer ring.

It depends on how wide and well corrected your eyepieces are. Once in a while I pop in one of my ES-92s without putting the GSO CC in first and get apprehensive about why they're performing so poorly at the edge even at f/6. Then I realize I have forgotten to put the CC in the focuser first. Put it in, and my stress levels decrease markedly. As mentioned above, the GSO CC will add SA at high powers, so I remove it for high power observing. I do the same with my TSFLAT2 in my refractors to get the sharpest on axis images at high powers for the same reason. If you're just using 40 to 50 degree orthos and plossls at f/4, other edge aberrations such as astigmatism will completely overwhelm any coma from the mirror because these simple eyepieces were simply not designed for fast scopes. A CC will help flatten the field and remove coma, but eyepiece aberrations will remain. If you're using Nagler and Ethos eyepieces, you would naturally want them to perform at their best and add a TV Paracorr T2, so it depends on your eyepiece collection. BTW, at f/4, the coma free section on axis is only 1.4mm (0.022mm x f-ratio³) in diameter for the comatic aberration to fit within the Airy disc. A TV Paracorr T2 will extend that to at least 40mm.

Sounds like you need to move to Texas. Excellent seeing on many clear nights, and winter nights are mild. That, and you don't have to deal with snow and ice very often, and cars never rust out due to road salt. We really need more upper Midwesterners moving down here to balance out all of the Californians moving in. As far as mass production Dobs vs custom Dobs, I really notice the difference in the motions and focusers. Balance, smothness, and sticktion have been well thought out in custom Dobs and their focusers tend to be buttery smooth in use (Feather Touch, MoonLite, or similar). I don't have the time to tinker with a scope to perfect it. I'd rather pay someone local to the US or Europe to build it right from the start. Does anyone espouse buying Chinese made cars over US, Japanese, and European cars, and then upgrading all the bits and pieces to make them road worthy?

True, but based on my comparative imagery through my 127 Mak and a slow, ultrawide smartphone camera, it's much less than the NT4s: The 12mm and 17mm NT4s SAEP make it all but impossible for me to take in the entire view once you push in close enough to see the field stop. They're not as bad as the Meade MWA 26mm which also has some CAEP, but you expect better from Tele Vue. I felt betrayed by Al. They were his 3rd released iteration of 82 degree eyepieces. There was no excuse for leaving SAEP in the design at that time (let alone at that price point).

Keep it clean, this is a family oriented forum. 😙

I bought a generic version (Wollensak) of the Hyperflex 7.2mm-21.5mm from Surplus Shed, and I measured the usable eye relief to be around 10mm. Just look at the tiny eye lens (16mm diameter) and how much it's recessed (it's the third eyepiece from the left), and you'll understand why. The Celestron Regal 8-24mm zoom is second from the right. I unscrew the entire eye guard to use it with eyeglasses (15mm of usable eye relief with its 26mm diameter eye lens). There's really no way to use the Wollensak with eyeglasses except to see the central portion of the view.

I'm jealous you got to compare views against a 9.25" refractor.

Sorry to hear you didn't get on with non-click stop zooms in a binoviewer. I've had no problems. I just roughly zoom the two eyepieces until I reach the desired magnification in my dominant eye. I then zoom the other eyepiece back and forth a bit until the image scales and field stops merge. It usually takes less than second. It's much easier to tell when best magnification matching has been achieved than when best focus in monovision has been achieved. The two images just snap together all of a sudden. I've never experienced eye strain using them.

Check out this almost 7 year old AMA bulletin about blue intense LED outdoor lighting. Perhaps refer to it when complaining locally. There's probably a UK equivalent warning out there as well.

It's pretty obvious based on turnout at public star party outreach events around here that only a tiny fraction of the population have any interest in amateur astronomy, even in or near big metro areas. In my experience, those interested tend to be families that want to broaden their kids' experiences or are adults that come from techie backgrounds with an insatiable desire to learn new things. Elitist perhaps, but many of these same people drive technology forward for the betterment of the other 99% of the population.

Domo arigatou misuta roboto is the extent of my Japanese. 😉 The coolest part is I used to design IBM mainframe and super computer processors and systems.