Tele Vue type 5, 31mm eyepiece.

[jock1958]

Bought my 31mm T5 Nagler over  3 years ago off a fellow SGL’r in as new condition. 

It works very well on my Tak FC-100DL + Skytee 2, its a chunky bit of kit but the views through it are impressive, I also bought a TV eyeguard extender which allows for comfortable eye placement.

As John mentioned you need to slide the OTA forward in the tube clamp to balance things out.

I also tried it on my Tak FS60 for kicks, it does work but the focuser struggles and it’s a faff trying to balance things out. 

[nicholasastro]

I had a 31mm Nagler T5 until very recently. It's a great eyepiece but I found I was not using it, weight and size being the primary reasons. I have since acquired a 30mm Pentax XW and find that I use that all the time, even under my moderately light polluted skies. What I like about the 30XW is its clarity - it's almost as though there is no glass in the way. However, the true field of view is a bit smaller than the 31T5. I have not tried the 30mm APM UFF but I'm definitely sticking with the 30XW as I'm very impressed.

[Don Pensack]

20 hours ago, nicholasastro said:

I had a 31mm Nagler T5 until very recently. It's a great eyepiece but I found I was not using it, weight and size being the primary reasons. I have since acquired a 30mm Pentax XW and find that I use that all the time, even under my moderately light polluted skies. What I like about the 30XW is its clarity - it's almost as though there is no glass in the way. However, the true field of view is a bit smaller than the 31T5. I have not tried the 30mm APM UFF but I'm definitely sticking with the 30XW as I'm very impressed.

The 30mm XW and 30mm UFF have almost identical field sizes (36.2mm and 36.3mm respectively), but the UFF is sharper in the outer 10°.

[in a 12.5" f/5 scope operating at f/5.75 with a Paracorr II.]

The UFF is also lighter than the XW and has a couple mm more effective eye relief.

I see the UFF is now available at FLO under the Stellalyra name:

https://www.firstlightoptics.com/stellalyra-eyepieces/stellalyra-30mm-ultra-flat-field-2-eyepiece.html

It's not like the XW is a bad eyepiece at all.  In this case, it's more in the nature of small nuances.

[nicholasastro]

2 hours ago, Don Pensack said:

The 30mm XW and 30mm UFF have almost identical field sizes (36.2mm and 36.3mm respectively), but the UFF is sharper in the outer 10°.

[in a 12.5" f/5 scope operating at f/5.75 with a Paracorr II.]

The UFF is also lighter than the XW and has a couple mm more effective eye relief.

I see the UFF is now available at FLO under the Stellalyra name:

https://www.firstlightoptics.com/stellalyra-eyepieces/stellalyra-30mm-ultra-flat-field-2-eyepiece.html

It's not like the XW is a bad eyepiece at all.  In this case, it's more in the nature of small nuances.

I find the 30mm XW incredibly sharp right to the edge at F/4.4 with Paracorr. In terms of eye relief, there is plenty, even for eye glass wearers.

Of all my widefield eyepieces, and I have many, this is the one I enjoy the most - it is very special - together with my 17.5mm Morpheus.

I believe the 30mm Pentax XW is an underrated eyepiece and I know quite a few very experienced observers who feel the same way. My only regret is that I didn't discover it sooner!

 

[John]

I was loaned a Pentax XW 30 and a Nirvana 28mm by FLO a few years back to compare for a few weeks with my Nagler 31. All great eyepieces I thought and I could have lived with any of them 🙂

 

 

Edited April 1, 2023 by John