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janoskiss
20-03-2006, 01:38 AM
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. :P

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.

matt
20-03-2006, 07:21 AM
You're obviously very happy with this EP Steve!

Any idea who'll be stocking these once they arrive in OZ?

How do you think they'd compare with the XW range?

Shame they're available in only 2 focal lengths. Wonder why?

janoskiss
20-03-2006, 11:00 AM
Star Optics are the people I've been talking to.


:shrug:

Because Pentax make them primarily for their spotting scopes.

ving
20-03-2006, 11:06 AM
ever thought of painting your eyeball black? ;)

sounds like a great EP steve... :)
thanks for the info. now a 30-35mm version of this would be interesting :)

janoskiss
20-03-2006, 11:17 AM
Well, I have thought about FMC contact lenses. :P

XW-30 or XW-40 are only $700 a pop. :eyepop:

ausastronomer
20-03-2006, 12:47 PM
Matt,

At less than 50% of the cost of the 1.25" Pentax Xw's you have to expect them to be slightly inferior. Pentax traditionally have been a company that gives you "quality comparable to purchase price".

If however, the quality is even approaching the XW's they will be a dayyam good eyepiece for $200.

I may order the 12mm when they are released to try them for myself.

CS-John B

Starkler
20-03-2006, 12:50 PM
If thats the US dealer price then expect them to be something like $AU250-300 here.

It would be an interesting shootout between the XF, the TV radian and the Burgess/TMB planetary.

janoskiss
20-03-2006, 02:30 PM
John, probably a lot of the extra cost of the XW goes into that extra 10 degrees of FOV. As far as what I've seen in my f6 Dob so far, if the XWs are even better than the XF across a larger FOV, then they must be phenomenal. But even if they are "only" as good, they would still be tops. :)

Geoff, From most US dealers the XFs are 1/2 the price of the XW within a few dollars, so I'd expect them to be 1/2 the price of the XWs here too.