Pentax XF Zoom Spotting Scope Eyepeice for PF-80ED, PF-80ED-A, PF-100ED. PF-65ED and PF-65ED-A Spotting Scopes

Bought from Amazon Warehouse, no longer in original packaging but at a substantial cost savings. As other reviews note the zoom is quite stiff when new but does loosen up with use. As received the zoom is much stiffer than on either my Baader or Svbony zoom eyepieces. I have manipulated the zoom ring on this one enough so it is beginning to loosen. Very short throw on the zoom ring of only about 90 degrees. Presumably a return as a few scratches visible on the chromed metal nose piece so apparently tried in a non compression ring equipped eyepiece holder.

Pentax makes this eyepiece for their 65mm spotting scopes but I use it for astronomy. In fact, I use two of them in my binocular telescope because they have much better light throughput than any other brand I've used (though I've never looked through any Zeiss eyepiece). I see more individual stars in a field and more of the glow from a galaxy through the 8.5XF than Televue e.p.s The Pentax XLs are better known in the hobby, probably because they have a slightly wider apparent field of view and also because there is a greater range of focal lengths to choose from than the 2 e.p.s in the XF line (I believe the other is 12mm and it's reported that field curvature is a problem with that one-no such problem with the 8.5).

I bought this to go with the PF80ED and thought this was the high end eye piece, but realized later that it wasn`t. When it arrived, I used it with the PF80ED ..... I do not know what the view from the more expensive lens would have looked like, but I am very satisfied with this lens and scope body combo. I can only compare it to a Leupold 40x60 spotting scope that I had previously used, but the view from the Pentax is extremely clear and has a very sharp view. I wanted this for 200-500 yard viewing of targets with a .224 cal bullet and I have not been able to get to the range and see exactly what this combo does, but what I have looked at from my back deck at various distances is impressive. I had a chance to purchase the more expensive eyepiece before I knew what was what, but I missed the boat. I really would like to have compared the two lenses and see what difference there is. Oh well I got a very good price on the eyepiece and PENTAX PF80ED body, sooo ... ignorance is bliss on this one .... I am very pleased with what I have.B Schmidt

I use this 8.5mm eyepiece with a 9-1/4" telescope when the seeing conditions allow for 276x magnification, such as for planets, small nebula or double stars. I have a number of quality brand eyepieces to choose from but I usually select one of the Pentax's. I'm not sure why, others might have some supposed advantage in field of view, side shielding eye-cups etc. The Pentax's probably win out because of their comfort of use. Looking at faint celestial objects requires patience and time for the atmosphere and the eye to be aligned just right and so an eyepiece that is easy to center and focus gets the results. If I sell off some of these toys, the Pentax's will be the last to go.

The 12mm XF is a great eyepiece - very high contrast on planets and deep-sky. Excellent fit and finish; adjustable eyecup and excellent eye relief. Sharpness and contrast rival my Takahashi orthos. The 8.5mm XF is great as well.

Excellent eye piece!

good for close work but no ED glass makes it worthless at anything farther than 200 yds

This was purchased for use in a Pentax 65ED. My other occulars are the green ones and this does not equal them but then it cost much less. I would not purchase it again.