Don Pensack

Ah, yes. Well, there are fewer focal lengths (8 in XW, 9 in Delite, 5 in StellaLyra 80°) Will Long Perng introduce more focal lengths? Unknown. You can see how the 14mm compares to a 14mm Morpheus here: https://www.cloudynights.com/topic/769375-eofb/?p=11103180 and the following post.

You mean Delos, not elite. Actually, 80° is quite a bit wider than 70-72°, and the feeling of field size is that it is a lot larger. The 80°, though it has a long eye relief, needs a replacement of the included eyecup to be usable with glasses. See reviews of the Orion LHD eyepieces. Without glasses, they're just fine.

There are now reports appearing on CloudyNights and apparently it is very good, so another good eyepiece in the mix. By the way, I just posted the 2022 Eyepiece Buyer's Guide there.

The brass split ring is placed low in the adapter. It's possible it grabs on the 1.25" barrel on some eyepieces. But if it grabs the lip and tilts slightly, it can cause problems with removal. Some of my customers have had this problem. I do like the fact the adapter is threaded for 2" filters, and can even act as a camera adapter for cameras with a 1.25" tube by threading directly to a t-thread below it. It's got some nice features. But the ring that grabs the eyepiece should have been 15-20mm long, like some Twist-Lock adapters.

1) it's not adjustable and doesn't grab some slightly undersized eyepieces well and there is no way to tighten it. 2) it still binds with a thin brass split ring, not a long collet, and it can get hung up on some undercuts.

I'm not sure I remember exactly the several hundred post thread on Cloudy Nights back in 2002-2005, but I don't think Zeiss actually produced the Astroplanokular. It appeared after WWII as a product licensed to Ohi Optics (Masuyama). As late as ten to 15 years ago Kasai Trading in Japan was selling the Kasai Astroplan eyepiece, also from Ohi Optics, with the same internal design as the Astroplanokular of Zeiss.

It's been around several years. Just look for reports on the William Optics UWAN 28mm.

36.2mm field stop compared to 42mm. The Nagler has a true field 16% wider. If the magnification in the 31mm is too low for most purposes though, you're right--the 21 would get more use.

I don't think Svbony is a manufacturer, but just a reseller of already existent Chinese products under private label. Most of their products were available years before the Svbony label (which was formerly Vite). But, you put your finger on the differences between inexpensive eyepieces and expensive ones: Expensive eyepieces will have better corrected outer fields, both in terms of chromatic aberration and astigmatism, may have wider fields on top of that, and better control of light scatter on bright objects. If all you're doing is looking at the center of the field, there is very little difference between eyepieces.

Here are the Japanese company's specs for the LVWs: https://www.cloudynights.com/topic/445618-how-many-elements-in-a-vixen-lvw/?p=5767670 5,6,7, or 8 lenses.

Some information about it: https://www.cloudynights.com/topic/363923-the-edmund-1-18-lens-description/ and a pic: http://www.astrosurf.com/luxorion/Illustrations/edmund_scientific-catalog-astronomy-1962.pdf See page 23 in the old catalog. Edmund described it as a Kellner, but also mentions it has 2 achromatic lenses inside. That is because Edmund called Plössls "Kellner Type III" eyepieces. [Kellner type I was the regular Kellner, Kellner Type II was what became RKE] Here is a picture instead of a drawing (scan through the images to see--it's the all-black eyepiece) Click on any image to see it larger.: https://astromart.com/classifieds/astromart-classifieds/eyepieces/show/rare-vintage-edmund-scientific-rke-plossl-set-excellent Note: The barrel had no filter threads, there was no field stop (so it had a vary vague field stop and just faded out at the edge), and it worked only so-so below f/8. I had one in the '60s with an f/10.5 scope and in the early '70s with an f/15 scope and it worked fine. I bought one used in the '90s and even in my SCT of the time, it was not a good eyepiece.

I had an even older eyepiece than that early RKE--a 4 element Edmund eyepiece labeled 1-1/8" for the focal length.

Depends. Just looking for a larger exit pupil? A very cost-effective way would be the 30mm APM Ultra Flat Field or one of it's rebadged brothers. Looking for a larger true field? Then you want a larger field stop eyepiece, like the 31mm Nagler or 30mm ES 82°. Of course, the second option also gives you the first.

I have, and extensively compared it with a 14mm Baader Morpheus and several other eyepieces at a dark site (m.21.4+ skies) It has some issues: 1) It does not have 20mm of eye relief with the threaded-on eyecup provided. That eyecup sticks up about 8mm above the lens, reducing the eye relief to about 12mm. That would be fine if you don't use glasses at that focal length. Unfortunately, I do, and it was inadequate for glasses use. Removing the eyecup exposes your glasses to being scratched by the aluminum top of the eyepiece. The thread is 50mm, so finding an eyecup to fit isn't going to be easy. I stretched a smaller eyecup onto the eyepiece and folded the rubber inward to cover the aluminum top of the eyepiece with rubber about 0.5mm thick, and the eyepiece was usable with glasses at that point. 2) The eyepiece has some highly reflective surfaces inside the eyepiece and the eyepiece has some edge of field brightening I did not see in the Morpheus. I took the LHD eyepiece apart and blackened the internal spacers, lens edges and housing and this reduced, but did not eliminate, the edge of field brightening. I communicated with LongPerng about it, but they admitted the eyepiece had a bit of a problem with scattered light but that they were "working on it to do better". Other than those two issues (I kept the 14mm Morpheus and gave away the LHD), the eyepiece is nice and sharp to the edge. Color rendition is good, and the eyepiece works fine at f/4.5. It's a very modern eyepiece, but I have to admit to being mystified why someone would design an eyepiece with enough eye relief for glasses and then put it in a housing that eliminates its suitability for glasses, and that applies to the entire series. I guess the outer shell designers paid no attention to the results of the optical designers.

An observation: the 12mm and 17mm ES92s are not free of SAEP either. A lot of people have noticed this.

Long eye relief (long enough for glasses). Comfortable observing (adjustable eyecups). Wider field than Plössls, but no less sharp. TeleVue Delites. I bought 3. Now I own all 9. They are that good. I'm just sayin'.

The 5X Powermate also has a significant change in magnification with distance from the lens. See: https://www.televue.com/engine/TV3b_page.asp?id=53&Tab=_app I think it is unlikely it is the same optical confoguration as the other PowerMates.

Yes, it's called an Extension Tube. FLO sells them, as do many other retailers.

Which will solve the problem. I use copper tape. Don

Already responded to the same post on CN. Can you achieve focus by pulling the eyepiece + PowerMate out of the focuser a bit? How much. For 1/4", don't sweat it, just do it and tighten it down. For 1/2" or more, look into getting an extension tube (available everywhere).

LOL. Their recommended setting for the 17mm Nagler was off by one setting, too. ES has some wrong information in their eyepieces spec chart, Baader has some field stop errors in their eyepiece spec chart, APM has incorrect field stops listed for their UFF eyepieces. I could go on and on. As they say, Doveryai no proveryai: Trust, but verify.

some major links on filters: Planetary: https://www.cloudynights.com/topic/713148-planetary-filter-shootout/ https://www.cloudynights.com/topic/533147-spectroscopic-analysis-comparison-of-planetary-filters/ Nebula: https://www.cloudynights.com/topic/527199-spectroscopic-analysis-comparison-of-nebula-filters/ https://www.cloudynights.com/topic/598011-nebula-filters-tested-over-a-2-year-period/#entry8205435 Comparative charts: https://searchlight.semrock.com/?sid=a08a1af9-84ee-49d2-959d-153d7e7c0eb8#

Nebula filters increase contrast by reducing the light from the sky without dimming the nebula. A narrowband, UHC-type, filter passes hydrogen emission line and the 2 O-III lines in the spectrum and little else. Without knowing the spectrum of emission of the nebula, this is the 'universal' type of nebula filter. [Nebula filters do not work on dark nebulae or reflection nebulae] If the object has little hydrogen emission, but is strong in the O-III lines, narrowing the filter will increase the contrast even more. So, narrowband--all nebulae, and especially the larger hydrogen gas clouds forming stars (M42/43, M8, M20, M17, M16) O-III for planetary nebulae, supernova remnants, and Wolf-Rayet excitation nebulae. Brands to look for: Astronomik UHC and O-III, TeleVue Nebustar and O-III, DGM NPB, Lumicon UHC and O-III, Chroma UHC and O-III, ICS UHC and O-III 2nd choice: Orion Ultrablock and O-III For planets, the most effective filter I've used is the Baader Contrast Booster filter. It is the one I reach for nearly every time. The Baader Moon & Sky Glow is also good, but a bit less effective on Mars than the CB. For the Moon, you really only need a filter at low powers--at high powers, the moon is kind of dim. But a variable polarizing filter is most useful, though a 25% transmission neutral density filter also works well.

Well, I was wrong. Meade brought the filter back in the late 2010s when they were owned by Sunny. It's still available new from many suppliers. It's $40 to $64 in the US, so you got a good price. I hope it works in your scope.

The coatings on the X-Cel LX are better. The old S4000 Japanese "Super Plössl" had excellent polish, but lesser coatings so more internal light scatter on very bright targets like planets and Moon. Also, eye relief on the X-Cel LX will be consistent across the line, where the older "Super Plössls" will have an eye relief of approximately focal length x 0.7. Only usable with glasses longer than 25mm. The S4000 came in 3 Japanese versions: 1) 5 element, smooth side, no rubber eyecup, Japan stamped in the black aluminum 2) 5 element, with rubber eyecup, Japan stamped in the black aluminum 3) 4 element, with rubber eyecup, Japan stamped in the chrome barrel. The S4000 have had multiple versions over the years, one from Taiwan, and several from China, but those 3 versions are the only ones I know of from Japan. In a SkyWatcher Dob, I'd get the X-Cel LX: --more comfortable eye relief, especially at high powers for planet viewing. --more modern coatings --more drift time before you need to move the scope because of a wider true field and wider apparent field. Another competitor of the X-Cel LX you might look at is the BST Starguider eyepieces from FLO. Might be a bit less expensive and pretty much equal.