Pentax XF 12mm/8.5mm

[Gadget]

Sorry guys another eyepiece question I’m afraid

Now I have decided to get either Wo Swan or Sw Panaview for low power I am looking at getting a couple of good planetary eyepieces and was set on getting a couple of TV Radians but the Pentax XF 12mm/8.5mm keeps popping up although there is not a great amount of reviews about there is a few on CN and it is compared to the Radian and it seems to have it beat comfortably in most areas but I don’t see it mentioned on here that much does anyone on here use them? And are they that good if so are they one on those gems that have seemed to have slipped through the net

Thanks

Kev

[NGC 1502]

Hi Kev. I've never looked through a Pentax XF eyepiece, but I do own some Radians.

If you are ok with a 60 degree field, I think they are tough to beat, good in a fast scope,

even my 6" F4. And the 20mm eyerelief is great if you wear specs, and for sharing the view

with others.

But if you are looking for a 12mm, then I don't know of any dealers that have one.

Some say that Radians are being discontinued to make way for the new one from Televue,

the Delos. Telescope House have the best stock I've seen, but no 12mm.

So the used market if you want one.

But maybe with your 9.25 and its tolerance for eyepieces, you need not spend so much ?

Regards, Ed.

[russ]

The Pentax XF is a beautiful eyepiece. Owned both models, the 8.5 is slightly better than the 12 in a fast scope. But in the C9.25 both will be perfect. Basic specs are the same as the Radian with 60deg field and long eyerelief. The few reviews there are put the two neck and neck with a few pros and cons either way.

The Pentax has the obvious advantage of lower price and arguably better coatings too. The TV has better build and a larger range to choose from.

I wouldn't hesitate to fully recommend the Pentax XF. If the focal suits your scope (and the 12mm does perfectly), then i can't see any reason to choose the Radian over it.

[great_bear]

are they that good if so are they one on those gems that have seemed to have slipped through the net

The words field curvature seem to crop up when these eyepieces are discussed - the very mention of which is likely to put people off.

Of course, in practice it might not be an issue, but the phrase is off-putting.

[russ]

The words field curvature seem to crop up when these eyepieces are discussed - the very mention of which is likely to put people off.

Of course, in practice it might not be an issue, but the phrase is off-putting.

From what i remember the field curvature affected the 12mm not really the 8.5mm. And it's not really a deal breaker in the 12mm.

[lunator]

I have the 12mm version. I have used in my OMC250 (F9) and ST120 (F5) and it is brilliant in the OMC and good in the ST. I am happy to recommend it.

Cheers

Ian

[russ]

There's an in-depth comparison of the 12mm Radian and XF here:

12mm Radian and 12mm Pentax XF - Review

And a thread on CN comparing the XF and Radian:

http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/3452422/Main/3450860

As i said in my first post, they are neck and neck. With perhaps the XF nudging it as the better eyepiece overall.

[great_bear]

From what i remember the field curvature affected the 12mm not really the 8.5mm.

It's greater in the 12mm, but present in both to some degree.

it's not really a deal breaker in the 12mm.

I thought that might be the case - but as it's scope-dependent and I'd had problems with curvature in the past, I wasn't prepared to take the risk. Sounds like I missed out

I was also put-off because there are designed as spotting scope eyepieces, not astronomical ones; I figured the design priorities may be different.

[russ]

It's greater in the 12mm, but present in both to some degree.

I could see it in the 12mm when used with the F6 200P. But it wasn't at all distracting. I've tried a number of times to buy one back but always miss out.

That said i used Keiran's 12mm Radian at the last SCAG night and it was spectacular. Pin sharp edge to edge, great contrast and really comfortable. Would love one as well.

I really like these widefield long eye relief planetary eyepieces. They really make sense to me. Any slight loss in performance compared to the Baader GO is worth it.

[andrew63]

I think it is probably safe to say here - albeit it quietly - on cloudy nights you would gets your visa application blocked! but I feel that both pentax and vixen lens in general are superior to televue.

The coatings are probably better and light throughput higher - subtle difference i know but it adds up to providing a higher grade of optic.

andrew

[great_bear]

Any slight loss in performance compared to the Baader GO is worth it.

Indeed - I don't have any BGOs anymore - comfort being the main reason.

[Gadget]

Thanks for the input people very helpful looks like i will order one of these now

I could see it in the 12mm when used with the F6 200P. But it wasn't at all distracting. I've tried a number of times to buy one back but always miss out.

That said i used Keiran's 12mm Radian at the last SCAG night and it was spectacular. Pin sharp edge to edge, great contrast and really comfortable. Would love one as well.

I really like these widefield long eye relief planetary eyepieces. They really make sense to me. Any slight loss in performance compared to the Baader GO is worth it.

Encouraging to see you have tried to get another Russ was there any particular reason for selling

I have tried a BGO just couldn't get on with on with eye placement and the small dot of glass but some on CN have mentioned the XF to be on par with a BGO for sharpness / contrast etc

Thanks' again all

Kevin

[andrew63]

I think you would be happy with either Kevin - but at £119 from FLO - they are exceptional.

The pair were intended for use in pentax spotting scopes but obviously they are superb for astronomical use.

[Gadget]

I think you would be happy with either Kevin - but at £119 from FLO - they are exceptional.

The pair were intended for use in pentax spotting scopes but obviously they are superb for astronomical use.

Thanks Andrew

I have now placed my order for the 12mm and also the Panaview 32mm and a skywatcher 2" O111 filter

Oh well looks like bread and water for a week or so im sure the wife and kids will understand

Kevin

[andrew63]

When the dark skies return, especially as not much out on these lens, i plan to compare how the XF 8.5 compares with a vixen 7.5mm plossl.

[russ]

Thanks Andrew

I have now placed my order for the 12mm and also the Panaview 32mm and a skywatcher 2" O111 filter

Oh well looks like bread and water for a week or so im sure the wife and kids will understand

Kevin

You won't be disappointed with that little lot Kevin. It will be worth the bread and water rations for a while.

I sold my pair of 12mm XF's (and binoviewers) to fund an Imaging Source DMK camera. What a huge mistake. I couldn't get back into the imaging and ended up selling the camera anyway. You live and learn (not!).

[Gadget]

Thanks Russ

They have all arrived now (very quickly) and the Panaview looks amazing just what I like in a eyepiece big heavy and loads of glass and a real feel of quality and the Pentax looks rather different from most eyepieces I have used but also has a real nice quality feel about it and the coatings on the lens looks very nice but looking at the weather it will be quite a while before I get the chance to use them

Kevin

[russ]

Good service from FLO

The SMC coatings on the Pentax are one of the things that make it special. The coatings are arguably the best in the business. I know what you mean about the appearance though. It looks a little plain and dull compared to the standard high gloss look employed on most eyepieces there days. But the optics are top notch.

Enjoy the new bits