Louis D

Try smacking the eyepiece sideways into your open palm with the debris side facing downward. You may be able to displace the debris to the side wall.

Search on CN. There's lots of reports on them there. Basically, extremely fine polish, low glare/scatter, high contrast. However, the edge falls apart in sub f/8 scopes starting at 50% out from the center. The faster the scope, the worse the edge looks. If you simply look on-axis and use the outer field for context, they're reportedly great. They're supposedly terrific in slower scopes (think f/10 and higher).

Yes, they were one of the earliest eyepieces with the dual fit barrel (1.25" and 2"). Of course, Tele Vue had their 2" skirts before that, which Meade copied, but boy were/are they annoying. There's not enough 1.25" barrel left to securely fasten it into a 2" to 1.25" adapter, so you have to use it in 2" mode, even if that means having to crank the focuser way out to reach focus. I fixed that with my 12mm NT4 with a 2" extension ring and 5 O-rings: Which dovetails nicely with your topic because that lowest O-ring sits on the lower taper of the 2" skirt's undercut. That made it impossible to get a parfocal ring to tighten on the slope where I wanted it to be. It kept wanting to slide down into the undercut where it was too wide, so the ring wanted to tip. I gave up on the parfocal ring and switched to the O-ring solution as a result. Right there with you. I've had eyepieces become nearly inextricable after snagging the compression ring and pulling it up and out of its channel, jamming the eyepiece in the tube in the process.

And price. 😆

In Nebraska, we were observing from the center line at a liquid fertilizer depot. They had workers moving tanks around. As long as we stayed well away from them and left no trash, they were okay with us being there. As more people showed up closer to noon, the business owner gave all his workers an impromptu couple of hours off so they could get their families and observe the eclipse as well. They were oblivious to what was going to happen right above them. I picked the tiny town on purpose figuring that would be the case, and I was right.

How well does the Plossl design of the NPL hold up at sub-f/5 focal ratios in your experience? Tele Vue's Plossls are modified with slightly concave outward facing surfaces to get better correction at shorter focal ratios:

The field reducer is not going to play nice with widest field 2" eyepieces like the 41mm Panoptic or 40mm Pentax XW. It might play fine with shorter focal length 2" eyepieces, though. 2" eyepieces are mostly useful for when the (effective) field stop approaches or exceeds the inner diameter of a 1.25" barrel. They are also useful for securing big, heavy eyepieces like the 12mm ES-92. Otherwise, there's no important reason not to go with 1.25" eyepieces at the shorter focal lengths. Having an f/10 scope makes having a wide range of exit pupils difficult. To get to even a 6mm exit pupil requires a 60mm eyepiece. The closest would be a TV or Meade 55mm/56mm Plossl. An exit pupil this large is mostly useful with narrowband nebula filters like an OIII. If you start at 40mm as suggested above, you would have a 4mm exit pupil as your widest. Next, a 30mm such as the APM UFF would yield a 3mm exit pupil. A 20mm/21mm such as the StellaLyra 80, Ethos, or APM XWC HDC would get you to an optimal 2mm exit pupil. At 1mm exit pupil, you could go with a range of eyepieces from 9mm to 11mm. There's the 9mm Morpheus or APM XWC, 10mm Delos or Ethos, 11mm Nagler T6 or Apollo. Below 1mm exit pupil, your options become extensive. You could go with Morpheus, Delos, Ethos, Delite, Nagler, Pentax XW, Nikon SW, or various orthos. I would not go below 5mm for a 0.5mm exit pupil, though. My limit is closer to 0.7mm with a 7mm eyepiece.

Here's an old post on CN by Don related to this. He mentions 22mm, 8.8mm and 6.5mm future focal lengths. That 22mm would be huge and heavy!

As I say in this post in my Svbony 20mm thread, they do make for a excellent pairing in a binoviewer at long f-ratios, so keep that in mind. You're not going to be able to pair up the StellaLyras in a 1.25" binoviewer. 😁

The StellaLyra UWA 20mm might be your best bet for long eye relief and excellent correction, possibly better than the APM XWA 20mm. I've been happy enough with my 22mm NT4 to not feel tempted to buy one to find out first hand, though. Here's a report on one here on SGL:

See my thoughts in the thread below: Long story short, you wouldn't like it in your 12" scope.

Well, 5 years ago on August 21st, I was in Nebraska capturing this image: But I have absolutely no idea what I was doing on August 11, 1999. 😁

Rather than live with that focuser kludge, I'd probably just buy a GSO 6" f/5 Newtonian Reflector Telescope (in stock) or GSO 6" f/5 Newtonian Reflector Telescope with LB Focuser Upgrade (once they're back in stock). Since I already have a decent alt-az setup, along with plenty of storage space, this would make more sense for my situation, and possibly others as well.

This 6 year old thread (to the day) is the only one I know of anyone trying to add an R&P focuser to a SW Heritage scope:

So, the spike spins around the star on the side opposite to wherever your moved your eye? It sounds a bit like a reflection somewhere. I've had bright planets have ghost images in some eyepieces that I can chase around the view in this same manner. It's just weird that it extends as a spike rather than as a dimmer point of light. Look down your eyepiece, diagonal, and focuser tube in daylight to look for shiny surfaces that may need flocking or at least blackening.

To my knowledge, the only cause of a single spike in a Dob/Newt would be if the secondary is held by a stalk rather than a spider. If you were using a correct image diagonal in a refractor or cat, the Amici prism can also introduce a single spike on bright stars. You're not referring to a lobe pointing away from the center of the FOV are you? That could be coma, astigmatism, or lateral chromatic aberration.

Probably any 4 element or more eyepiece would be an improvement over the SW 28mm three element eyepiece. It's probably a Kellner or Konig variant, so not very good at f/6 or at 56° (28° half angle) AFOV. Notice how spread out the dot plots get at just 10° off axis for simple designs at f/5: However, notice that the Erfle type, even with 5 elements, is far from perfect. In my experience, at f/6, most of the superwide eyepieces under $100 are probably sharp to about 50% to the edge and then start to degrade slowly until at around 75% out where sharpness rapidly declines to the edge. If you only look on axis, they'll probably perform satisfactorily. If you tend to let objects drift from edge to edge and watch them the entire way, you won't be pleased.

Another option might be to use a 2" focal reducer ahead of the binoviewer. This would compress more field into the same image circle. Some downsides would be an increased need for in-focus and outer field distortions.

You could contact Siebert Optics to see if they're still selling their 2" binoviewers.

UPS, FedEx, DHL, and Amazon always deliver to the front door, so less room for error as compared to cluster mailboxes. This does risk porch pirates getting to your package before you do. This does have the advantage over locked mailboxes in that once I see a package is delivered; but it isn't at my door, I can quickly go around the neighborhood checking porches for my package. Again, only USPS has done this when they've run out of parcel lockers (the big ones in the cluster picture). If you're wondering how parcel lockers work, they put the key in your regular mailbox (hopefully). You then take the numbered key to the appropriate parcel locker, insert the key, unlock it, and retrieve your parcel. The key is now locked into the keyway and the door slams shut, but not locked, on a spring.

We have 250 cluster mailboxes at the back of our subdivision, and it is all too easy for our postal workers to chuck mail into the wrong slot since they aren't well marked. Unfortunately, I have indifferent neighbors who can't be bothered with being neighborly. I think they consider misdelivered mail to be covered by this general rule in the US: Under state and federal law, recipients of unordered merchandise may keep the goods and are under no obligation to pay for or return them.

There's not much in that price range, new or used, that will vastly improve the view in the outer reaches of the FOV at f/6. If you doubled your budget, I'd recommend the 40mm Lacerta ED as a decent step up that gets you pretty close to 40mm Pentax XW level correction. At 30mm, the APM UFF and it's other brandings is exceptional while not being TV priced. You'll probably want to invest in a coma corrector at some point to clean up the edges and flatten the field a bit once you get eyepiece astigmatism under control (but not before). The GSO CC is probably the best bang for the buck out there. It's sold under many different brand names worldwide.

Lucky you to have a good neighbor. Mine just silently keeps my misdelivered mail and packages.

Why wouldn't it be the default? Does it draw too much power? Only SW knows for sure.

I've never had UPS or FedEx lose a package in 30+ years of shipping items. On the other hand, I've had the US Postal Service lose or misdeliver multiple items. I once had over $1000 worth of jewelry delivered to my neighbor's mailbox. They never deliver any of my stuff to me despite me dropping off theirs all the time. Different attitudes, I guess. I had to make the postal employee search their mailbox (they're locked) the next day to retrieve it without so much as an apology from them. Luckily, my neighbor doesn't check snail-mail very often. Once the USPS says an item is delivered, that's it. There's no possibility of insurance claims or anything else. They are infallible.