Wanted: 12mm eyepiece

[MortonH]

Hi, to go with my new 8" f/6 Dob, I'd looking for a decent quality eyepiece around 8-10mm. The 9mm GSO Plossl I got with the scope is not bad but could be better.

Am tempted to go for a Radian while Bintel have their sale on, but if anyone has any 'spares', let me know.

Cheers

Morton

[janoskiss (Steve H)]

Grab an 8.5mm Pentax XF from Frontier Optics. Not much over 1/2 price of Radian, and it is a better EP IMO. If you can afford it, grab the 12mm too; it would be a brilliant DSO EP for your Dob.

[MortonH]

Thanks, Steve. Similar specs to the Radians, I see. If my Pentax XL 21mm is anything to go by, these should be really good, and very atractively priced!

Morton

[davidpretorius]

I love my tmb 4mm planetary on jupiter in my f5 10" dob...it is awesome.....my gut feel is that the pentax xf may get the nod over it??

has anyone done a head to head on TMB versus Pentax Xf?

[MortonH]

I have a 6mm Radian for 200x and a 3-6mm Nagler Zoom for higher powers, although the Nagler hasn't seen much use in the past.

If I go for a 12mm (either Pentax XF or TV Radian) I'll have 100x native and 250x with my Powermate (which I love). Don't think I'll need anything else for high power in the near future.

David, how often do you manage to push the magnification up to 300x on your scope?

Morton

[davidpretorius]

Originally Posted by MortonH

David, how often do you manage to push the magnification up to 300x on your scope?

Morton

given that i actively cool my mirror so it is ambient and observe / image at 4am with jupiter high in the sky, i am using the 4mm almost religously every night i have clear skies. I have found that having a mirror over 1/2 degree over or under ambient is the major cause of bad seeing....

it is a nice ep for star testing with and I have definately enjoyed looking at the cores of tuc47 and eta carina with it.

TMB also do a 5,6,9 and another one that escapes me.

Frontier look to sell both pentax and TMB, maybe daniel has a feel for which performs best per $$??

[janoskiss (Steve H)]

The Pentax XFs are very much like the XWs ito optical performance and build quality - minus 10 degrees of FOV. IMO they are the best value EPs around, and true premium performers. The 8.5mm I have is superb even at f/4.

The TMBs are great budget EPs, and also fantastic value esp if you get the 3-for-2 deal. Optically very good, the only negatives: a little bit of scatter and *little bit* less contrast compared with the best and eye relief is significantly less than the stated 16mm. At f/6 they are comparable with premium widefields. At f/5 and faster edge correction is not as good as some pricier EPs. Build quality is good for the price, but there is no denying that they are budget EPs. I have only used the 7mm.

[davidpretorius]

thanks steve, that gets it clear in my head.......ep legend as usual!

[Starkler (Geoff)]

The xf is a step ahead of the tmb in build quality and light scatter/contrast.

If you can get the tmb 2nd hand or on special they are good value, but if not I would go for the xf.
Another good one is the Vixen LV if you dont mind a smaller fov.

[MortonH]

Changed thread slightly as I've decided to go with a 12mm ep only at this stage. Will probably go with the Pentax XF unless something else pops up. Thanks for the advice.

Morton