I went to the Photonics West SPIE convention this past week in San Jose
CA. There must have been well over 1000 optics companies in the
exhibition hall, an incredible turnout. I visited all I could in the
time I had, but stopped the longest at Elcan's exhibit, as they were
showcasing their new 5" f/5.5 apochromatic refractor. All optics and
mechanics were designed and manufactured at Elcan. They had it trained
on an overhead fire sprinkler at about 100X, several hundred feet away
across the San Jose Convention Center. The lighting appeared through a
diffraction grating to be high-brightness mercury vapor, so there was
plenty of violet and blue light reflecting from the chrome-plated fire
sprinkler, and several near-point source virtual images reflected in it.

The imagery was absolutely spectacular - the best I have ever seen in
any apo I've viewed through at any star party. I racked in and out of
focus, and the image blur was perfectly white regardless of focus travel
- absolutely no trace of any color fringing at all, an amazing feat
considering the mercury vapor lighting with all the violet and blue
lines present. The imagery at focus was so sharp, so perfectly defined,
and so bright and scatter-free that the visual impression was basically
that there was no telescope in the path. It was like I was up on a
cherry picker about a foot and a half from the sprinkler, directly
looking at it, even perhaps with cheaters on.

We discussed when they might introduce it commercially, and they are
still discussing how and when, so I know very little. They are looking
at a fair range of apertures and focal ratios. They were wisely and
carefully limiting their conversation, but did comment when asked that
the lens is "well below" 1/10 wave P-V in green light. I can only pass
on to you that their telescope produced the sharpest imagery I have ever
seen in 33+ years in optics and astronomy. I would love to have the
chance to star test it sometime.

Something to watch for in the near future.
Mike