Louis D

Just look and listen for aircraft when using lasers. The ones getting arrested are lasing police helicopters or landing aircraft from the end of the runway. I've switched over from Telrad/QuikFinder (I have both) to laser sight (check on ebay) as my neck and back have gotten stiffer and more painful to contort. I can be on target with a laser sight in under 5 seconds if bright stars or planets are nearby. From there, I generally rely on a wide field 2" eyepiece to center the object. I have a RACI, but don't find myself using it much. For times when the sky is washed out, I'll use SkEye on my mounted smartphone to get to scope within a few degrees of a target. This image shows my RACI, GLF, and QF setup. While this image shows my RACI, SkEye, QF setup.

The filter material is probably stressed in some manner. It may also be too thick to be optically transparent. Baader Solar Film is really thin and mounted unstressed. Wrinkles or wobbles in the surface don't matter. I've been using BSF in homemade cells since it first came out over 20 years ago to good effect.

To the cleaning cloth. This was seemingly left out. Never put cleaning fluid directly on a lens, ever, at least while they're still in their lens cell. Windex or other ammonia/detergent based glass cleaners work very well in my experience to get stuck-on grime off. Just don't scrub. Unseen micro-grit can scratch the lens coatings. Instead, leave a damp cleaning cloth on the lens for a bit of time if needed to loosen grime, then lightly wipe again. You can finish up with dedicated lens cleaning solutions. If the lenses are still grubby, you could get a lens wrench/spanner and remove the retaining ring holding it in the lens cell. Next, put a small dowel or similar up into the cell to support the lenses. Finally, lift off the lens cell and clasp the lenses. Set the lenses down carefully on a folded towel and note their orientation. You could even mark the edges with a dark permanent marker showing alignment and which way is up along with the stacking order. Now you can put a folded towel in a plastic tub in the kitchen sink and fill it with soapy dish detergent water. Let the lenses soak for a bit and then repeat the cleaning steps, except using running water and your soapy finger tips to immediately flush away any unseen grit that works loose. I've salvaged some pretty grimy lenses this way. Again, finish with lens cleaning solution if you see any remaining streaks or water spots when viewing reflections from a bright light at an angle to the lens.

The FAA (US) prohibits all spare (uninstalled) lithium batteries from traveling in checked baggage: Spare (uninstalled) lithium metal batteries and lithium ion batteries, electronic cigarettes and vaping devices are prohibited in checked baggage. They must be carried with the passenger in carry-on baggage.

I'm planning on traveling toward Uvalde for the eclipse despite its recent infamy. The farther south and west you get in Texas, the higher the probability of clear skies on any given day/night. It's marked with the cyan dot. You could go all the way to Eagle Pass (gold dot), but I'm not keen on being that close to the Mexican border. Really, though, anywhere in the red outlined area should give you the highest probability of clear weather along the path of totality. Once you get east of I-35 or north of I-20, the weather is generally cloudier and more humid due to the proximity to the Gulf or because of jet stream propelled storm systems. Simply pull up a map of the US and turn on satellite view to see for yourself. Where it's greener is where there is more rain. Where there is more rain, there are more cloudy days/nights.

Another possibility is that SAEP is so strong that once you get close enough to see the entire FOV, you start fighting kidney bean blackouts. I get this quite strongly with the 12mm and 17mm NT4s along with the 20mm Meade 5000 UWA and 26mm Meade MWA. It almost feels like the eyepiece is fighting back and doesn't want to cooperate with your eye. I have never looked through a 13mm NT6 given the short eye relief, so I have no idea if it has any SAEP like its predecessor the 13mm NT1 or kinfolk 12mm NT4, but that might account for difficulty seeing the entire field at once.

Here are some other wide field options at 12mm/12.5mm: The discontinued 12mm Nagler T4 which I have and don't really care for. It does have an 83° AFOV. The 12.5mm Morpheus as others have said. It supposedly has a 78°AFOV, so not that far behind the 13mm NT6. The longish eye relief might put you off, though. The 12.5mm Noblex which supposedly restarted production and is supposed to be superb across its 84° AFOV. The 12.5mm APM Hi-FW which I have and like quite a lot. Given the longish eye relief, you might not like it, though. It has an 80° AFOV. The 12mm ES-92 which I also have. It's huge and 2"-only, but a joy to use with its 92° AFOV. The TFOV is roughly the same between those last two thanks to opposite types of edge distortion.

I've had trouble with heavy eyepiece/diagonal combos causing my AT72ED focuser to slip downward when used near zenith. It didn't matter how much I tightened up the central tension screw or roughed up the tube flat (rack). I eventually bought a 90mm APO with a helical R&P focuser for use with heavy eyepieces or a binoviewer. It will still unravel if I loosen off on the tube tension, but not otherwise. I had to buy an 8" dovetail bar and mount the clamp just about even with focuser knobs to reach balance on the AT72ED. I never had any balance or load issues even with my old DSV-1 mount and certainly none with my DSV-2B mount. I would think your scopes should be long enough that this won't be such an issue. You'll just have to try it out and see how it behaves in each focuser. If you can get the Terminagler for about $525 or less (USD equivalent), then you'll be right in line with typical US used prices and should be able to resell it for no loss.

Or $175 shipped to the US (no additional taxes for us). If I didn't already have a 22mm NT4, I'd probably order one.

Right, but I was referring to the 9mm and below focal lengths. It wouldn't be unprecendented for the shorter focal lengths to diverge in quality from the longer ones. The Redline 70 degree eyepieces are supposed to be pretty bad at 8mm and below despite the 22mm being excellent and the 17mm pretty good.

The 14mm and 20mm seem to receive universal praise. There's very little known about the 4/6/9mm versions. There's are recent CN thread asking for information on them, but little has come to light. One learning from one post is that they may suffer from SAEP (kidney-beaning). It's not even clear how severe it might be. Jump in and get one and let the world know what you think of it.

I remember someone using a long 6" refractor on a DM-6 at a local star party. It worked fine with it until you wanted to change eyepieces without losing your target. It has no axis clutches, so you had to carefully keep the scope from nosediving while swapping heavy eyepieces (2+ pounds) in and out. That's one of the reasons I upgraded from my DSV-1 to DSV-2B mount. I love the latter's axis clutches while swapping eyepieces.

Exactly. I literally bought a pair of used binoculars off of CN classifieds that were way off on collimation. The seller claims they never had merging issues.

When I asked, the responding moderator said it was to prevent siloing of discussions. However, by that measure, why not just lump all equipment discussions together?

His numbers pretty well agree with what I measured. Sharpness is excellent from 8-5mm with falloff below that. Focal lengths were pretty accurate for 8-5mm, with 4mm being off a bit (4.3mm) and 3mm being 3.5mm. Eye relief decreasing from 11mm to 6mm going from the 8mm setting to the 3mm setting seems about right. I just couldn't measure it accurately with the limitation of my methodology. Where we noticeably diverge is for AFOV: AFOV for me was 8mm=58°, 7mm=59°, 6mm=59°, 5mm=60°, 4mm=61°, 3mm=61°, so a nice, almost linear progression in size increase. I did not detect any of the decreasing, increasing, decreasing AFOV going from 8mm to 3mm with a minimum at 6mm of 55.5°. I re-edited my AFOV image to more dramatically show how the AFOV increases from 8mm to 4mm in a fairly smooth manner, and then remains constant to 3mm: This doesn't fit with Ernest's numbers very well: 3 4 5 6 7 8 58.9 61.3 57.3 55.5 56.5 58

Hmmm. The thread that would not rest in peace. Put to rest initially in 2006, resurrected in 2011, 2013, and now 2023. This might be something of a record for SGL.

Unless you get lucky and find a Canadian Astro/Photo shop with new-old stock zooms sitting on the shelf, you're probably going to have to depend on the secondary market. Since you're in Canada, you're well positioned to make inquiries. BTW, that zoom was a stretch for my astro budget back then. I think I paid about $270 after all the cross-border costs were figured in. That's about $480 today. I will say that the 5-8mm zoom is very enjoyable to use once you get past the non-parfocality of it. It is sharp edge to edge at f/6. I compared it directly to the new Svbony 3-8mm zoom here: I'm done now. I was in the middle of composing the above reply when I got the notification, but I wasn't going to abandon it.

I would suggest putting out a Wanted ad on UK based classifieds and also on Astromart and Cloudy Nights classifieds in the US. There just might be someone willing to part with theirs. I've had mine since new in the 2000 time frame, but I won't be parting with mine anytime soon. It was Antares in Canada that marketed them. I bought mine through O'Neill Photo in the Toronto area back in the day because they had no US dealers. He closed up his shop long ago due to retirement. Mr. Speers's first name is Glen. I gather Glen Speers is still actively designing and manufacturing his Speers-Waler eyepieces in Canada, now in their Series 4 iteration. Perhaps Antares could put you in touch with him to find out what he's up to these days.

I'd probably be happiest with a 4 position 2" turret. That way, I could quickly swap out a 40mm SWA for a 17mm HWA, then to a 10mm/9mm SWA, followed by 5mm SWA. This would cover all but my binoviewing observing pretty well. It's rare that I jump to 17mm HWA and say to myself, would this look better in a 22mm UWA instead? The same goes at 9mm to 12mm. I almost randomly choose one because the view doesn't change a whole lot in that range. It is really only at the highest powers where you're teasing out the highest usable power that night that zooms really strut their stuff. That, and in binoviewers where turrets aren't really feasible and eyepiece swapping is a pain.

Unless you demand parfocality, my 5-8mm Speers-Waler Zoom has a constant, measured, 78 degree AFOV through its range. Of course, I consider it a varifocal rather than a zoom, but it was sold as a zoom. They also made an 8-12mm version. There was also a device that could be inserted between the Smyth lens group and positive lens group for early Nagler type ultrawide field eyepieces to convert them into ultrawide angle zooms. I can't find references online to it anymore, but I think it was called "Zoom-Set" or something similar.

You are correct, and the OP does have the BHZ and prefers it to the Celestron Regal zoom (of which I have several and have never noticed any kidney-beaning). I haven't read of anyone touting any of the Svbony zooms replacing their BHZ except for the 3-8mm replacing their BHZ+2.25x Barlow combination. Aside from outreach usage, I doubt the OP would be particularly happy with the Svbony zooms. I suppose the Svbony zooms are cheap enough that the OP could buy a few and try them out.

Look at the OP's equipment list. I have a feeling a rather ordinary zoom like the BHZ would not be well received and would be resold or returned. By way of comparison, the Leica in particular is supposed to rival Pentax XWs in sharpness and contrast. It just suffers a bit at the edges in sub-f/5 scopes compared to the XWs.

Perhaps a SV171 Svbony 8-24mm zoom? They're only $51 on Svbony.com right now. I have no idea if there's a UK equivalent website, however. It's no Baader Hyperion Zoom, but if you combine your budget for multiple eyepieces into one, it would be no worse than a series of Plossls when used at f/5 as in your scope. There's also the Celestron/Skywatcher 8-24mm zoom which might come in cheaper in the UK.

I'm seriously OCD, and my eyepiece case(s) have no particular order to the eyepieces. It's more of a situation of where newer eyepieces would fit in the positions of older, retired eyepieces (or in adjacent, empty areas) because I didn't want to buy new P&P foam each and every time I upgraded eyepieces just to keep them in numerical order (cheapness wins over OCD for me every time). I literally have the positions of my eyepiece memorized, along with what used to occupy those spots previously, so no OCD issues for me in the dark.

The 19mm Panoptic is diminutive and was designed with binoviewer usage in mind, along with the 24mm Panoptic. A natural result of this is limited eye relief, which you've stated is not an issue for you. If you like small, jewel like eyepieces, you'd probably love the 19mm Panoptic. You might also want look into the 16mm Nagler T5 which has a slightly larger TFOV while being only a tiny bit heavier than the 19mm Pan.