[Wavytone]

The optical designer was a personal friend of Markus. Not Long Perng. His name appeared somewhere on CN.

The metalwork may well be by LP as I'm sure these would have been manufactured in China, and it would be quite usual to involve the manufacturer in the barrel design to optimise the assembly and testing.

Another aspect is whether these have undercuts or tapers on the barrels - in some photos they are tapered, others they aren't - and its still totally unclear what the situation is. A while back several on CN made it quite clear to Markus that most wanted straight tubes because the tapers and undercuts combined with compression rings frequently lead to the eyepiece being decentered or tilted.

I'd be happy to buy one or two to see if they're any good - if they had straight barrels - but the reply I got from Markus was ambiguous.

My other reservation remains the number of elements. Vixen achieved superb results with their SSW eyepieces with 2 fewer elements so its clear these APM ones aren't pushing any envelopes, optically, and the coatings would have to be something phenomenal to beat the SSWs (I have the 7, 10 and 14).