One last post before bed after being out observing with my new eyepiece: a Pentax XF. Stats:
8.5mm focal length
60 degree FOV
18mm eye relief
Pentax SMC coatings
I am most impressed with this EP! The build quality is in a league of its own. The polished alloy barrel, the tapered end of barrel for easier insertion in the focuser, the immaculate blackening of the filter threads, ... It's truly exquisite! Makes Televue EPs look like they were made in your garden shed.
Secondly, the performance is superb. I have compared it with my 7 and 9mm HD ortho, 2x barlowed TV plossl and 1.6x barlowed Stratus 13mm. It is on par with the best of them, HD orthos, on transmission, contrast and sharpness but has a generous FOV and long eye relief. Unsurprisingly, it is well ahead of the barlowed Stratus in terms of transmission. Observed: Saturn, Jupiter, Moon, Orion Neb and friends, star clusters in Crux and Carina, Eta Carina...
Edge correction could not be much better in my f6 Dob; better than Panoptics.
And it is a bit of a bargain too at $US149, or about $AU200. To be available in Australia soonish (so I've been told). If anyone was thinking about getting the 8 or 13mm Stratus for around $180, they should seriously consider getting an XF instead (which only come in two FLs: 8.5mm and 12mm).
I have two complaints however.
First is that damn reflection off the eyeball and back again with Jupiter (and little bit on Saturn too) that just about all wide-/semiwide-fields seem to have. Naglers & Radians certainly do. (Look for the "fairy" dancing around Jupiter.) Panoptic (in a well-baffled barlow but not in the Powermate) is an exception amonts the wide fields. HD orthos and Televue Plossls don't show the reflections either (even when barlowed). I think it has to do with the size and shape of the lens.
Second, the click-stop adjustable eyecup (which has 4 settings) does not extend far enough for me, I still have to pull back a bit, so eye relief is too long. It must be the shape of my skull becayse this is pretty typical for me with most mid-to-long eye relief eyepieces and most binoculars too.
