Louis D

In what scope do you plan to use it? It performs best in slower scopes (SCTs, Maks, CCs, slow refractors, etc.).

Depends on your budget and ability to find the Meade used. The 24mm UFF has a significantly wider TFOV (27.5mm FS) than the 25mm HD-60 (24.9mm). It also has better edge correction, although the very edge sort of fuzzes out because the design was pushed too far. Sharpness-wise, they're similar. Usable eye relief is similar in both. The UFF weighs 12.2 ounces while the HD-60 weighs 7.5 ounces. Since I have 2" focusers, I much prefer the 22mm AT AF70 (Omegon Redline SW) at that TFOV and power. It's better than either sharpness-wise across the field with about the same TFOV (28.6mm FS). Oberwerk sells a 1.25" version singly if you contact them directly. See below for images at f/6 in a field flattened 72ED:

A Japanese made Meade 4000 4-element vs 3000 comparison would seem interesting. I wonder what distinguished them from each other.

Does anyone know if the 3000 series was intended as a value line by Meade? Was it ever repackaged into a rubber grip barrel like the 4000 line? I wonder if the later 4 element 4000 series was really a repackaged 3000 series.

Well, I had a quick first light with the 2.5mm Planetary TMB II eyepiece in my AT72ED. Here are my recollections: Its field of view appears to be flat, sharp, and color free edge to edge after looking at Luna at nearly full phase, Jupiter, and Saturn. I didn't notice any imparted color tone on Luna. Craters, NEB/SEB, and rings all looked clean and well defined. Stars and Galilean moons appeared pinpoint edge to edge with no refocusing. I didn't see any flaring, glare, scatter, ghosting, etc. I didn't see any indication of bright objects just outside the field of view casting light into the FOV. There is no thin blue line at the field stop nor any false color on the limb of Luna. There is just barely enough eye relief to take in the entire FOV with my eyeglasses pressed to the retracted and folded eyecup, so I'd estimate about 15mm of ER. However, at that tiny exit pupil, my astigmatism was a non-issue without eyeglasses. The AFOV appears to be on the order of 60 degrees. I'll have to run it through my testing measurements to get an exact number. I did not try to check for edge astigmatism on a bright star because none were handy. However, it would seem to have very low levels if it is present. The eye cup tube twists up and down smoothly through maybe 1cm of travel. The eye cup itself flips up and down and seems just the right stiffness to stay in place. I didn't notice any kidney beaning (SAEP), ring of fire (CAEP), general blackouts, or edge of field brightening (EOFB). It is labelled AQUILA, not TMB, as in the stock image below. I'll take and upload images of my eyepiece when I get the chance. The matte black color, rubber grips, and chrome bands make for a handsome looking eyepiece. The tapered undercut is very shallow and caused zero issues inserting or removing the eyepiece into/from a compression ring eyepiece holder. I saw no debris in the FOV on the face of Luna. Overall, a very impressive debut by a $35 eyepiece. So far, I highly recommend it. I'll have to do eyepiece/Barlow comparisons sometime when I have more time, and I'm less exhausted from a busy Saturday. Aquila brand: instead of TMB Optical which is probably best since I'm sure TMB's estate isn't getting any royalties on the sale of these eyepieces.

Which 4000 series? The original Japanese 5 element smoothies, the same in a rubber grip barrel, or the various 4 element Chinese made versions? Don't quote me, but I think there was even a Japanese made 4 element version.

Don beat me to link to Ernest's tests. I refer to them often as a double check on my own testing. We're generally in pretty close alignment. Here's Ernest's general eyepiece testing forum: http://astro-talks.ru/forum/viewforum.php?f=32&sid=2ae665e58ed7af435f7ca61502fcbf44 and in organized/indexed form: http://astro-talks.ru/forum/viewtopic.php?f=7&t=1897#p29513 An xls spreadsheet of my testing results: Eyepiece-Data-Summary v1.0.xls A few of my threads testing eyepieces:

In the daytime, you will definitely be benefiting from the pinhole effect. The smaller the pupil opening, the greater the depth of focus. I also wonder if the spotting scope is slightly slower (higher f-ratio) and as such has a slightly greater depth of focus. I know if you stop down a telephoto lens, it will have greater depth of focus. I would try both scopes under identical viewing conditions. Same lighting, subject, etc. I would also try an off-axis aperture mask on the H150 to see if depth of focus improves any.

Me too. When Outdoor Photographer switched to digital-only during the height of the pandemic, I couldn't bring myself to do more than glance through the photos. I let my subscription lapse.

Which Meade UWA 14mm were you using? There was the vintage 4000 version (actually 2, smoothie which I have and recessed eye lens with rubber grips) which I've found has terrible stray light control and outdated coatings, and the newer 5000 version which may have been either JOC (ES/Bresser) or some other manufacturer (pre/post ~2013). Side-by-side, I found the 14mm Morpheus better than the 4000 version in all respects. It wasn't even close.

Try using a very bright star dragged across the entire field of both looking for stray light control before it ever enters the field of view, at the edge, and as it crosses the field. Repeat with Jupiter. It may well be they behave identically. Next try viewing a dim star cluster right at the edge of being perceived. Search along the Milky Way to find some relatively unknown dim ones. See if there is any difference in presentation between the two eyepieces. With this, you're testing for sharpness, transmission and contrast. Dragging it across the field can also reveal vignetting if dimmer members simply vanish from view near the edge.

I would also compare on axis sharpness, contrast, flare control, haloing, ghosting, etc. You're generally going to do most of your critical observing in the central 50%.

I bought myself a used TS-Optics Photoline 90mm FPL-53 triplet APO for Christmas pre-pandemic just to try something different. I use it on a DSV-2B mount. I've really enjoyed its different presentation of planets in particular from my Dob. They seem sharper and contrastier, if a bit less ultimately detailed. There's basically no false color in focus even at high powers. I'd say go for a really good FPL-53/FCD-100 or equivalent doublet or triplet in the 90mm to 100mm range. FPL-51/FCD-1 doublets show noticeable violet fringing at higher powers in my experience, so that's why avoided them as I moved up in size. I haven't tried a triplet using these glasses, so I can't comment on them. You'll need to leave about $500 to $700 for accessories like a 2" diagonal, an alt-az mount, and a sturdy tripod. The nice part is, all of these can be carried over to SCTs, Maks, and CCs in the future if you want to branch out into catadioptric designs someday.

Unfortunately, that's all too true. It's only with back to back comparisons that you start to realize how eyepieces differ from each other, and how each has its strong and weak points.

Bizarre. It would be interesting to understand how this happens through ray tracing. Perhaps it's related to SAEP.

I would have thought it would just cause severe vignetting of the field. How could it induce optical aberrations if it has no optical elements?

I lived for years (at least 15) with a 38mm Rini MPL, 14mm and 5.2mm Pentax XLs, a 9mm Vixen LV, and a 1.25" Tele Vue 2x Barlow. That was it, believe it or not. 🤫 The slippery slope began when I bought a 40mm Meade 5000 SWA on clearance along with a GSO CC back around 2013. The combo was so much better than the 38mm Rini that I began to seek out more and better eyepieces. And the rest, as they say, is history.

Just curious why you chose the 31mm BHA over the 30mm APM UFF. Was it simply to complete your Hyperion set?

Since mine are from so many different companies, I'd go with a hodgepodge of eyepieces.

No idea, but you get the prize for the longest thread title with the relatively shortest actual post. 😁

I guess that's me. Sometimes I forget to put it in the focuser, and put one of my ES-92s in without it and instantly think, "What is wrong with this eyepiece tonight, it's usually sharp to the edge?". Then I realize I forgot the CC, put it in the focuser, and all is well with the world again. 😁

To be universally adaptable, it needs to have M48x0.75 threads. My GSO 2x 2" Barlow optical element has this size thread. Yours appears to be the Chinese made version, so I can't speak directly to its threading. The upper part of the GSO spacer tube is not M48 threaded. It's more of an SCT thread, although I've never verified this.

I use a TSFLAT2 substituting for the nosepiece of my GSO 2" Dielectric diagonal. Since the diagonal has SCT threads, I use an SCT to M48 thread adapter, plus 15mm of M48 tube extension, to attach the M48 threaded TSFLAT2 in front of the diagonal. This effectively flattens the field of view to unnoticeable levels visually. I couldn't stand using my 72ED refractor for low power, wide field viewing until I figured out this hack.

That, and the OP hasn't visited SGL since a week after posting the original question.

Did it filter out any unwanted artifacts to make up for the green cast? I'm guessing it's cutting into the red as well as the IR to cause this color shift.