[Profiler (Profiler)]

The Pentax XW's in general have a very good reputation although I have never looked through one myself. Having stated this caveat I have looked through both the 5mm T6 Nagler and 3-6 Nagler zoom - both of which struck me as exceptionally good EPs.

When looking at Saturn and keeping all elements constant (scope, diagonal etc) the Zoom at the 5mm setting (and all other settings for that matter) had a slight but clear edge in terms of contrast, clarity and crispness of what I could see. So, for pure optical performance the zoom was better than the standard 5mm Nagler. Additionally, the zoom is brilliant in being able to fine-tune the magnification to whatever increases or decreaes you think your equipment can handle on any particular night and whatever you might prefer in terms clarity versus magnification. The big stumpling block for the zoom is the fov. This is not however a problem if you have a tracking mount in which case the problem is nullified as the mount will simply maintain the target in the fov for you and thus you get all the benefits of the zoom with none of the disadvantages.

Having stated all of this the 5mm T6 Nagler is by no means an optically shabby EP either and is also amazingly clear and sharp when you appreciate that it is an 8 element design versus 5 in the zoom. However, where the 5T6 really excels is naturally in the fov if you are not using any sort of tracking mount. The object remains in the fov for sometime and you will find yourself using this EP alot for its ease and comfort and quick pragmatic set-up.

Finally, with respect to ER both are roughly the same and ironically not too bad at all in terms of comfort. I find them both easier to look through than Tak LE's which are meant to be the ER eyepieces by Tak. In terms of comfort for pure extended observing I would probably tip my hat towards the 5T6 but the zoom is still pretty good