Louis D

That's what I have my Z-team case for. I have Kellners, reverse Kellners, 70 degree Konig variants, Rini modified Plossls, etc. in it.

I have ES-92s stored vertically without problems in my old Doskocil XL case. It's equivalent to the Pelican 1600 case. The problem becomes one of extreme weight with so many 2+ pound eyepieces (including 30mm ES-82, 40mm Meade 5000 SWA, etc) in one case and having bad shoulders. I could store my eyepieces horizontally if I went to a long enough gun case like this guy did on CN:

No, it just means you need to get another eyepiece case. I recently added my sixth case. I had my A-team, B-team, Z-team, binoviewer, and Meade HD-60 cases already, but I needed somewhere to put some largish eyepieces I seldom use yet keep for comparison's sake.

Definitely share your experiences here when you get the 13mm in.

This was done in daylight at an astro shop side by side with Pentax XLs, both eyeguards set to the proper height for my eyeglasses. The XLs had zero blackout issues while I was continually chasing the classic kidney bean around the field of view of the Radians. I'm sure at night, except on the moon, it wouldn't have been an issue. I decided to go with the XLs because of the lack of kidney beaning and slightly wider field while still being just as sharp.

I passed on the Radians 20 years ago after trying them out and discovering they had massive SAEP (kidneybeaning). I haven't discovered any in the Meade HD-60 line.

I recall reading about a C11 user who got so frustrated with Crayford focuser sag and slippage that he switched to a Clement focuser instead. Don't discount your focuser's ability to counteract sag under heavy imager loads.

Comparing the Meade HD-60 9mm and 6.5mm to the 10mm Delos, 9mm Morpheus, 7mm Pentax XW, and 5.2mm Pentax XL, sharpness, edge correction at f/6 and stray light control were all pretty similar. The main edge the more premium eyepieces had was a slight improvement in contrast likely due to better polish leading to slightly less scatter. Today's step-up 60 degree eyepieces are very good in the sub-10mm range.

Yes, you probably need more spacing. The shorter the focal length, the greater the field curvature in a refractor. That flattener is optimized for a certain focal ratio range, but curvature mostly varies by focal length. I use a TS - 2'' Field Flattener - Universal Field Flattening Lens visually on my 72ED and have to space it out to about 127mm to get about the best correction for most of my eyepieces that focus at the shoulder. Their values suggest the following: • Achromatic refractor f/5: 100mm to 105mm • Refractor f/6.6: 103mm to 109mm • Refractor f/7.5: 105mm to 110mm For the very short 72ED, these values are no where near long enough. As a guess, I'd say to try adding 8mm additional spacing to start with. I'm basing this on your corrector doing the same work as mine in half the distance (55mm vs 110mm) and I needed to add about 17mm additional spacing.

The original Vixen LV line had a 7mm that got dropped with the NLV line. Their LVW line had an 8mm.

Pick up a used 8" or 10" Dob for a quick grab and go option. Sure, you'll have to manually track, but it's manageable.

The 10mm Delos is the only Delos I own. It is a terrific eyepiece. I'm thinking I might get the 6mm and 8mm Delos to slot in between my Pentax 5.2mm XL, 7mm XW, and 9mm Morpheus. Right now, my old Speers-Waler 5-8mm zoom covers those gaps.

Prime focus is generally located well above the most inward travel position of a focuser to allow various eyepieces to come to focus. The problem for the OP was that it wasn't at least 55mm, the required distance for a T-mounted DSLR. That Raspberry Pi imager should have no problems coming to focus in that scope (or any other for that matter).

I swapped out my venerable 27mm Panoptic of 20 years for the 30mm APM UFF this summer. All good things must come to an end.

I've been using Heavens Above for years to time ISS passes and Iridium flares. It has lots of other event timings and observing tools.

Unless you absolutely insist on having 82 degrees of field, the 30mm APM UFF is an excellent eyepiece with 73 degrees of measured AFOV and 16mm of usable eye relief. With the possible exception of on-axis sharpness, it outperforms my venerable 27mm Panoptic in all areas. It's considerably smaller and lighter than the 28mm Nirvana UWA if weight and size are an issue, and yet it only gives up 9 degrees of AFOV.

The main downside to it for me relative to the older 30mm ES-82 mushroom top that I own is that the 28mm WO/Nirvana's recessed eye lens vastly reduces eye relief for eyeglass wearers. Why even have a twist up eyecup if you're going to start by removing 5mm or more of eye relief in the fully down position? The 24mm APM UFF does the same thing, so I'm taking a pass on it as well.

@StuCan you check for central sharpness of stars in both? I can't get my original style 30mm ES-82 to focus stars to pinpoints on axis like just about every other eyepiece I own. They're always a bit bloated trying to find best focus between the blue and red sides of focus.

What about about two diagonals at 90 degrees to each other? The first would flip left for right while the second would flip top for bottom, or am I missing something? Would that yield the 180 degree rotation needed for a refractor image to correctly orient it?

Yes, I have heard that this is the norm due to the roof edge in the Amici erecting prism causing a diffraction spike. It's also my understanding that a porro prism or pentaprism would not cause a diffraction spike.

Having been observing for over 20 years, it's kind of exciting to see familiar patches of sky in a new way. You pick out relationships between objects you don't notice while panning about.

I use my 40mm Meade 5000 SWA all the time in my 430mm 72ED yielding 11x. I love sweeping star fields, looking at large OCs like the Pleiades, Hyades, Collinder 70, etc. I can almost take in the entire Orion complex at once with the 6.3 degree TFOV. The exit pupil is still quite reasonable at 6.7mm as well. My thinking is when you've got a short focal length, play to its strength, wide fields. For higher powers, I use my 127 Mak on the other side of my alt-az mount.

I would probably add a widest field 2" eyepiece like a 41mm Panoptic, 40mm ES-68, or 40mm Maxvision. Balance can be a challenge in a refractor with them, though. After that, you might consider swapping out the 24mm Hyperion for a 24mm Panoptic and the 10mm Hyperion for either a 10mm Pentax XW or Delos. I have the 10mm Delos and consider it to be near perfection across the field.

Here's a comparison review of the Zeiss E-PL 10x25 vs 24mm Panoptics in a binoviewer. There's a pair of these Zeiss eyepieces on CN classifieds right now.

Denis on CN posted a long series of descriptions of Zeiss microscope eyepieces and his experiences using them in telescopes a couple of years back.