Pentax XF 12mm vs Televue Radian 12mm

[F15Rules]

Just found this very comprehensive and interesting read on the above eyepieces.. https://www.cloudynights.com/articles/cat/user-reviews/eyepieces/televue-eyepieces/12mm-radian-and-12mm-pentax-xf-r1393. The author must have spent hour upon hour compiling that report, just so comprehensive..

As I've just bought at 12mm Pentax XF I'll be very interested to see how it works in my pair of fracs. I know it does have some FC, but I also know it has outstanding contrast, which is what I want from it. 

The XF 8mm and 12mm pair definitely offer a relatively low cost entry into Pentax eyepieces. And yet when I had the XF zoom (not the SMC XL one!) I literally hated it, great globs of CA all over the place. And yet again, many who use it for solar viewing (I used it for night time only) really like it. Odd.

I'll also be interested to compare the XF12 to my trust XL10.5, which is a superb performer, and also to my incoming SMC XL Zoom at the 12mm setting (which my wife just informed me has arrived today!) 

Dave

[michael.h.f.wilkinson]

I read that comparison some years back, and although it is very thorough in many ways, he got one simple thing wrong: the XFs are not scaled designs, as can be seen from the eye relief (which is the same in both the 8.5mm and 12mm. I rated the XF 8.5mm as a shade better than the Radian 8mm I used to have. It did not suffer from field curvature in a noticeable way. My fairly brief report is here:

I have since replaced the XF 8.5 with a Delos 8

[John]

I had the 12mm XF for a while. It was pretty nice, very well put together and easy to view through I thought but I did find the FC rather distracting. 

I still have a "gap" in my 1.25" eyepiece set at 12-14mm where it was - not sure whether to fill it or not

[25585]

Get a 13mm Vixen LVW - some still out there!

[F15Rules]

2 hours ago, 25585 said:

Get a 13mm Vixen LVW - some still out there!

I just sold my LVW 13mm....VERY reluctantly. I got the last new one from Tring Astro, very few new ones are left now.. John, I'd heartily recommend either the LVW 13 or the Morpheus 14 to fill your gap, at a very reasonable used price around £120-£130 in pristine condition if you can find one?..

I couldn't keep the LV213 AND get the Pentax SMC zoom, and I really like the versatility of the zoom from 8mm to about 16/17mm. The build on the Pentax is as good or better than fixed length XL/XWs, and apart from a bit narrower field (I think at 8-16mm I should still get 60 Deg at 8mm and c 50 degrees at 16mm), the overall sharpness on most UK nights will be indistinguishable, at least to my eyes.

And now I'll have the XF 12mm with its superb contrast for globs and nebulae like M42 at 60 degrees. It should work well with my Baader Hyperion Barlow 2.25x to get down to about 5.3mm, nicely fitting in between my Taks 3.6mm and 7.5mm for my high power needs..

Dave

[F15Rules]

4 hours ago, michael.h.f.wilkinson said:

I read that comparison some years back, and although it is very thorough in many ways, he got one simple thing wrong: the XFs are not scaled designs, as can be seen from the eye relief (which is the same in both the 8.5mm and 12mm. I rated the XF 8.5mm as a shade better than the Radian 8mm I used to have. It did not suffer from field curvature in a noticeable way. My fairly brief report is here:

I have since replaced the XF 8.5 with a Delos 8

I think the Delos is around 3x more expensive than the XF...how much better would you say it is Michael?

Dave

[iPeace]

4 hours ago, John said:

I still have a "gap" in my 1.25" eyepiece set at 12-14mm where it was - not sure whether to fill it or not

I thought you had a 13mm Ethos?

[Timebandit]

2 hours ago, 25585 said:

Get a 13mm Vixen LVW - some still out there!

 

 

14 minutes ago, F15Rules said:

I just sold my LVW 13mm....VERY reluctantly. I got the last new one from Tring Astro, very few new ones are left now.. John, I'd heartily recommend either the LVW 13 or the Morpheus 14 to fill your gap, at a very reasonable used price around £120-£130 in pristine condition if you can find one?                  

Dave

 

Yes these are getting very hard to find. I was lucky enough to find one from a member on SGL ,VERY recently?

[F15Rules]

5 minutes ago, Timebandit said:

 

 

 

Yes these are getting very hard to find. I was lucky enough to find one from a member on SGL ,VERY recently?

Congratulations Simon...I wonder who that was??!

Dave

[John]

1 hour ago, iPeace said:

I thought you had a 13mm Ethos?

I do but for some odd reason I count that as part of my 2" set

I keep a 2" barrel extension on it for 2" filters and it gets used in 2" diagonals / focusers but you are quite right that it's a 1.25" eyepiece really. Just quite a big one !

 

[iPeace]

1 minute ago, John said:

I do but for some odd reason I count that as part of my 2" set

I keep a 2" barrel extension on it for 2" filters and it gets used in 2" diagonals / focusers but you are quite right that it's a 1.25" eyepiece really. Just quite a big one !

Quite right, it's what I used to do...it's not a 2" eyepiece, but it should be.

It had somehow escaped me that the topic concerned 1.25" eyepieces, my mistake

[michael.h.f.wilkinson]

2 hours ago, F15Rules said:

I think the Delos is around 3x more expensive than the XF...how much better would you say it is Michael?

Dave

I got the Delos for a discount price from Okularem, which made a big difference. I would say the XF is not quite a 60° XW variant (close, but no cigar), whereas the Delos and XWs are very hard to separate. The Delos has a touch more distortion, but a slightly larger field. 

[Louis D]

3 hours ago, John said:

I do but for some odd reason I count that as part of my 2" set

I keep a 2" barrel extension on it for 2" filters and it gets used in 2" diagonals / focusers but you are quite right that it's a 1.25" eyepiece really. Just quite a big one !

 

It really depends on what you want to spend for a compact 1.25" 12mm eyepiece.  I assume the 12.5mm Docter and Morpheus are out along with the 12mm Delos due to size.  Perhaps a premium 20x Zeiss microscope eyepiece?  Maybe Denis on CN could recommend something.

[John]

I've never tried a William Optics SPL. There is a 12.5mm in that range which claims a 55 degree AFoV and 20mm of eye relief. Good offer from FLO on that one at the moment too .....

[Louis D]

2 hours ago, John said:

I've never tried a William Optics SPL. There is a 12.5mm in that range which claims a 55 degree AFoV and 20mm of eye relief. Good offer from FLO on that one at the moment too .....

They're the same as the various other Long-Perng 55 degree LER eyepieces as I recall.  You can search for user feedback on them under many other names, just keep 12.5mm and LER in your search and you'll get lots of results.  Overall, the 12.5mm gets very positive reviews.  Does it rise to the level of a premium eyepiece?  Who knows?

I have the 12mm Meade HD-60, and while it's good, it's no Delos.  On the other hand, the 9mm so far is impeccable.  I'll do some more comparisons as time allows over the winter now that the bugs are gone.

[iPeace]

10 hours ago, John said:

I do but for some odd reason I count that as part of my 2" set

I keep a 2" barrel extension on it for 2" filters and it gets used in 2" diagonals / focusers but you are quite right that it's a 1.25" eyepiece really. Just quite a big one !

 

...and then there's the 13mm Nagler Type 6 - which you didn't quite get on with? That surprised me, I love that one...

[Moonshane]

I am quite sensitive to CA and found the XF12mm I had and to some extent the Radians (and Delos/Ethos) showed a fair amount of lateral colour on the moon. I have therefore moved to plossls for binoviewing and Delites for higher power, Panoptics for lower power, none of which show this aberration to my eyes.

[John]

11 hours ago, iPeace said:

...and then there's the 13mm Nagler Type 6 - which you didn't quite get on with? That surprised me, I love that one...

Surprised me as well. I loved it 1st time around (pre-Ethos days)

 

[andre2]

Hi, do you think the 12 mm televue radian wold be a great eyepiece for a solar scope( coronado pst) to improve the contrast. ( compere to a celestron 12 mm plossl and a 10 mm ethos is too expensif and big) thanks.

[Louis D]

15 hours ago, andre2 said:

Hi, do you think the 12 mm televue radian wold be a great eyepiece for a solar scope( coronado pst) to improve the contrast. ( compere to a celestron 12 mm plossl and a 10 mm ethos is too expensif and big) thanks.

I wouldn't use any Radian on any bright subjects due to SAEP (kidney beaning).  SAEP was the main flaw to this line of eyepieces.  In daytime use in the store, I had to keep chasing the view to move the kidney bean around.  It was tiring.  At night on dark subjects (not the moon), they were usable because your iris opens enough to avoid cutting off the light cone.  I would think solar viewing would be like daytime or lunar observing with lots of kidney beaning.

[niallk]

Interesting + thanks: I wasn't familiar with the term SAEP before.

http://www.telescope-optics.net/eyepiece_aberration_2.htm

I really like my 15mm and 9mm plossls for Ha, but my beautiful-at-night Nagler 13T6 suffers badly from kidney beaning in my Lunt 50. Its a shame, because I really love its fov.

[andre2]

Hi, is the pentax XF 8.5 mm 60 degree a good eyepiece for SOLAR viewing. Thanks.

[25585]

Vixen SLV range has a good reputation. 9, 12, 15 if you can't find a LVW. They have 50 degree FOV. 

[andre2]

Thanks! I have a feeling that maby  the pentax XF is better for astronomics, and the vixen a bit better for solar(?) thanks! but the XF is small and light thats why i was curious also, i thought that iT was the brother of the PENTAX XF 6.5-19.5 zoom witch seem a Great “eyepiece” for solar. And i was also intent to use the eyepiece especially for “close up” views for the prommences in better seeings and  the 12mm Plössl  and 17 mm Plössl for surfice detail and grandulation. That was the plan. but iT seems that strange enough not mutch people use / have the XF for solar?? Thanks! ( i have PST)

[andre2]

Hi, i find a vixen LVW 8 mm in Holland .maby i go for that eyepiece espacially for close up prommences views in good situations? Of courc i already have a desent zoom, but i want to close my eyepiece colection with this one.the only downside maby is that this eyepiece is a little big and heavy....compere the the other ones. Thanks!