Quote:
Originally Posted by Profiler
Thank you Wavytone and Ausastronomer
You have both provided me with a wealth of information  .
From my perspective I am trying to pick a good eyepiece that will work well in my 80mm refractor AND - hopefully - won't be too shabby in a Dob as well.
I am not sold on the Pentax/Delos/LVW EPs as I prefer to avoid their big ergonomics (i.e. I like my EPs smaller where possible) but I do indeed like the ER they all offer.
I am really trying to decide what might be the best option amongst
Nagler T5 16mm
Nagler T6 13mm
Vixen SSW 14mm
Initially, the 16mm T5 Nagler seems to tick all boxes with one main fault - it has very limited ER of only 10mm
The 13mm T6 is about the same but the fov is little smaller but this is offset with 2mm extra of ER - so hopefully a bit more comfortable
The 14mm Vixen SSW seems perfect in terms of 13mm ER, good fov, great japanese glass from Vixen etc but no one seems to be able comment on how well they perform in Dobs etc. Indeed, I read one discouraging review which indicated that the outer 10% has significant astigmatisim. 
So - in summary - I am stuck and really not certain what is the best option which led me full circle to consider the 14mm Delos but then I remembered the issues with the Pentax 14mm XW and hence why I started this thread with my question about the Delos 
PS
DeLites seem to lack fov which I crave |
I would avoid the 16mm Nagler T5 at all costs. While the specifications state it's eye relief at 10mm, the "useable" eye relief is somewhat less than this. It isn't a comfortable eyepiece to use in any way shape or form, notwithstanding that it is pretty good optically.
The 13mm Nagler T6 is a pretty bulletproof eyepiece, if you can handle the eye relief, which is too short for me and to use with glasses on, but noticeably better than the 16mm T5. The eye relief on Televue eyepieces is measured from the top of the eye lens. This means that depending on the design of the housing and the eyecup the "useable" eye relief on a lot of the Televue eyepieces can be somewhat less than the stated eye relief. Just be aware of this. With eyepieces having a wide eye lens and a screw down eyeguard (eg Pentax XW, TV Radian and TV Delos) you get to use all of the 20mm of stated eye relief.
The 13mm Nagler T6 will work very well in both your dob and your refractor. Optically it is very good but I rate it marginally behind both the 14mm Pentax XW and the 14mm Delos in terms of sharpness, contrast and light throughput, but it is high quality. It also has a very nice compact form factor.
Also consider the 14mm Denkmeier. It's stated FOV is 65 degrees but it is actually closer to 70 degrees, possibly due to the AFOV being 67 or 68 degrees and the true focal length being 14 and a fraction. It is a very high quality eyepiece in every respect and it will give an excellent flat field view in both your newtonian and your refractor. It has 20mm of eye relief and a slightly smaller form factor than the 14mm Delos and Pentax XW's, but it is still somewhat larger than the 13mm Nagler T6.
Knowing what I know and having used all the contenders on numerous occasions if you want a slightly smaller form factor than the Delos and XW's with good eye relief and high quality optics I would be looking really long and hard at the 14mm Denkmeier.
Here is a review worth reading
Of course for $1,000 plus, the 12.5mm Docter will solve all your problems
It gets no better than the Docter.
Cheers,
John B