TheSkySearchers

Under their own brand name, Orion sells a range of (advertised) 20mm eye relief 80° AFOV eyepieces.
They are 4.5mm, 6mm, 9mm all 1.25" fit, and two 2" fit, 14mm & 20mm. I have the last 2. The range is made by Long Perng in Taiwan.

These Lanthanum High Definition eyepieces have 30mm diameter eye lenses. Their performance edge to edge in my F5 scopes is sharp, clear and bright. My 14mm shares duty time with my 14mm Morpheus, and the 20mm likewise with a 22mm Type 4 Nagler.

Eye relief and exit pupil behaviour are close between the 14mm rivals, LHD could do with a better eyecup, as I wear glasses. The Morpheus has a better eyecup, is parfocal with its shorther FL casemates & being 1.25" fit goes in my turret.

Comparing the 20 LHD & 22T4 is easier. 22 is heavier, and its eye placement & exit pupil behaviour is more awkward. 20 has the same rubber donut eyecup as my 14, and its eye relief is 17 to 18mm. I remove the eyecup and hover, that just lets me see the whole FoV, with a little head movement, its eye lens is almost flush with its barrel top and is less concave than my 22 Nagler's. Both eyepieces give rich immersive views.
In terms of value for money, 14 Morpheus & 20 Orion LHD are my choices. I will post some photos soon.

If anyone has experiences & comparisons with any Orion LHD eyepiece, please post.

14mm LHD:
--noted stars are sharp to the edge.
--with stock eyecup, not enough eye relief for my glasses, but I replaced it with a normal flip-up/flip down eyecup and increased the eye relief to the point where glasses were usable.
--the eyepiece had noticeable EOFB to me in dark skies, compared to the 14mm Morpheus, and I noticed a lot of bright interior surfaces.
I just got done taking the eyepiece apart and blackening all the spacers and lens edges to discover the primary reflections in the eyepiece came from 2 frosted surfaces on: the eye lens at the upper surface where it meets the aluminum of the eyepiece and
on the upper surface of the top lens in the negative field lens pair--an air-spaced doublet. After blackening these surfaces, no internal reflections are vision when looking through the eyepiece at a dark sky--a profound difference.
It remains to be seen whether this modification eliminates any EOFB. If it does, the factory can make a simple change and make the eyepiece better without redesigning anythng.
I have yet to use the eyepiece since modification. I will report back.

Thanks Don, looking forward to your review. If the EOFB is gone, or lessened, that would be great news. Which eyecup did you replace the donut with please?

I look forward to your impressions of how the modifications work Don.

25585 wrote: ↑Sun Jun 20, 2021 6:23 pm Thanks Don, looking forward to your review. If the EOFB is gone, or lessened, that would be great news. Which eyecup did you replace the donut with please?

49mm rubber eyecup, slightly stretched on. The rubber folds in toward the lens, protecting glasses from the aluminum, or folds outward, as normal.

The 14 and 20mm LHD eyelieces are my go to eyepieces in my 10 inch. I am tossing around getting the 4mm and 6mm

The modifications I made did not cure the EOFB, so I passed the eyepiece on to someone else.