Louis D

Have you looked into getting an observing hood to block local stray light? Even a black towel covering your head would help.

Obviously aimed at the Euro market since the majority of the US lies between 25° and 47° north latitude.

I've found a laser collimator best for aiming the secondary at the center of the primary. It's also handy to align the primary back to the secondary with a truss Dob while crouching at the back of the primary mirror. A sight tube or cheshire is best for centering and squaring the secondary below the focuser. I prefer to use a Rigel Aline to align the primary back to the secondary/focuser, assuming it is center marked with a donut ring. It also makes for a handy focuser cap, leaving just a small vent hole to allow the OTA to breath in storage.

Just make sure the BV you choose has locking collets instead of thumbscrews. Because the latter push the eyepiece off center to the side, merging can become an issue with them. I have the Arcturus BV with two useless Barlows (both induce the weirdest linear instead of radial coma) but without the eyepieces of the current version. I've never had trouble with the locking collets with smooth side eyepiece barrels. I use the nosepiece from a Meade 140 2x Barlow to reach focus, operating at 3x. I also tried inserting my BV into a Parks GS 2x Barlow (also known as Celestron Ultima and Orion Shorty Plus) and saw pretty much identical performance, so there are multiple options to reach focus.

I just measured the Sirius and GSO 32mm Plossl field stops directly using digital calipers after unscrewing each lower barrel to get clear access them. I got 27.2mm for the former and 27.1mm for the latter. I then did a comparative photographic analysis of each to the 27mm Panoptic accepting TV's 30.5mm FS diameter as gospel and arrived at 27.1mm for each. At no point was there a doubt that they have at least a 27mm diameter field stop diameter, the only quibble would be about that last 0.1mm.

There is a downside to larger clear aperture, and that is larger prisms (or mirrors) which require more available in-focus due to longer optical path length.

I've discussed binoviewers with some CN folks who have used several different high end binoviewers, and the main differences are in clear aperture size, mechanical construction, and accessories. Image quality doesn't vary much, so entry level BVs are just fine for planetary viewing.

Try it out, see what the image looks like, and report back on here. What's the worst, the view is terrible? Take a medium bright star at low power and sweep it from center edge and watch what happens to its shape and focus point. I often mix and match optical pieces looking to find hidden gem combinations. One is using the Tele Vue Panoptic Barlow Interface with the GSO 2x 2" ED Barlow. They work perfectly together. I also tried the PBI with a 6" long Orion Deluxe 2" Barlow from Japan. Horrible results probably due to the massive mismatch in expected focal length. The TV Big Barlow that the PBI was intended for has a fairly short focal length like the GSO.

You could skip a step and order pre-cut ProtoStar FlockBoard in the size closest to your Newtonian's tube. It just snaps into place, no adhesive required.

Probably because the market here was saturated with them during the 1980s and 1990s in particular. 8" SCT OTAs from that era regularly go for about $300. I think it's a perception that they're old and not worth as much as something shiny and new.

Good point that the 7mm LV was discontinued in the NLV and SLV lines. I believe the LVW had an 8mm rather than a 7mm.

Try a SVBONY 68° Ultra Wide Angle 20mm with a decent 3x Barlow to get ~7mm effectively. It's wide field, great eye relief, and quite sharp in such a slow light cone. I just completed a pair for binoviewing at 3x with a Meade 140 2x Barlow nosepiece and briefly wrote it up below: It certainly wouldn't cost much to try out the combination.

Pre-pandemic, they were fetching between $400 and $500 in good condition with everything included on CN classifieds. I haven't seen too many come up for sale during the pandemic, though. You could probably add $100 or so today thanks to inflation and lack of new SCT stock. You could probably take those dollar signs and convert them straight into pound signs since everything US made seems higher in the UK. About 6 years ago, I was tempted to buy a local 10" Meade LX200 for $400 off of Craigslist. However, it being driven by ancient electronics put me off of it. That, and it's sheer weight and bulk. Your model uses a much simpler motor drive, so there is less to go wrong with it over the years. They were packaged with pretty nice mounts by today's standards back in those days.

I could see that being useful for the OP based on living near NYC years ago. You literally can't see most stars on most clear nights to align on if you wanted to. The moon and brightest planets are about all that you can see without magnification. When I moved to Texas nearly 30 years ago, I was amazed to see a plethora of stars again as from my childhood days growing up in the upper Midwest. That's when I decided to get into amateur astronomy.

You could always add corner jacks to stabilize it:

Check with @Piero who uses a series of removable ramps to get his 16" Dob out the door with wheelbarrow handles on the rocker box:

As a practicing design engineer, the fact that it locks up at all with any customers says to me it has an unresolved design flaw. I'll wait on getting one until Baader releases an official fix for them or announces a recall.

Before spending big bucks on a single 7mm eyepiece for cyclops viewing, consider spending a similar amount for entry level binoviewers and a pair of 15mm to 20mm plossls or simple wide fields. Put a 2x Barlow or just the optics element ahead of the binoviewer to reach focus in most scopes, and you should be at about 3x. This yields somewhere between 5mm and 7mm effective focal length for those low cost eyepieces. I find I get much better views with two eyes and simple eyepieces than with one eye on the planets, and I've compared using XWs, Delos, and Morpheus eyepieces.

Keep working on your abstract photography technique, it might be worth millions in the NFT art market someday. 😉

For the amount it must cost to throw in that 20mm erecting eyepiece, you'd think they could throw in a decent Plossl or two instead.

But are the waterproof ES eyepieces dishwasher safe? 😁 I can't be bothered with wipes and little bottles of cleaning liquid. I just want to toss them in with the dirty dishes when they get grimy. Look! No grime and no oils. Never mind the etching, the important thing is, it's squeaky clean! 🤣

Which is what are found in prism based BVs that we are discussing.

That's a pretty broad generalization there. Do you mean relative to the 21mm, 28mm, and 40mm XLs or relative to all of them down to the 5.2mm XL?

The optical path length through prisms is shorter than through a series of mirrors.

Great, but I think you're still quibbling over details not particularly relevant to the OP's original question. I have measured my 32mm Orion Sirius and GSO Super Plossls to have 52° AFOVs each by the flashlight method and 51° and 50° AFOVs by the photographic method, and 49° eAFOV based on measured 27.1mm field stop. Again, my measurements might be off by about 0.1mm.