eyepiece selection suitable?
Posted 11 December 2012 - 11:57 PM
2" Baader 36mm x 72D
2" AT or similar 2x barlow
1.25" ES 11mm x 82D
Does anybody ever actually barlow big EPs (36mm)?
2" Baader 36mm x 72 (future)
1.25" ES 24mm x 68 (maybe),
1.25" Baader 8-24 zoom (24mm end of zoom is only 42*)
I don't know whether to get a 1.25" or 2" barlow with this lot.
As a 3rd option, I might just make do with the zoom and the standard EPs for now, but will want to upgrade in the not too distant future.
Posted 12 December 2012 - 12:17 AM
Posted 12 December 2012 - 07:07 AM
- I do recommend getting a longer focal length, wide field 2 inch eyepiece. You can increase the maximum field of view from about 1.3 degrees to about 2 degrees, quite useful in finding objects and the views should be quite wonderful.
- 2 inch Barlows are becoming more popular, I don't own one though I have been tempted a time or two. From my standpoint, the fundamental problem with a 2 inch Barlow is that it transforms a heavy, bulky, long focal length 2 inch eyepiece into a even heavier, bulkier, short focal length 2 inch eyepiece. With a Dob where balance is an issue, it doesn't seem like a reasonable choice.
The one good thing is that in a fast scope, a Barlow will help correct the eyepiece aberrations, so that 36mm transformed into a 18mm will be sharper off-axis in an F/5 scope but at F/8, this is of less value.
Posted 12 December 2012 - 08:02 AM
Another Aussie on...terrific.
2" barlows...don't bother just yet.I have one but have never used it. ES 11 is a good choice put a 1.25" barlow with it and it works!
I'd get the ES 35mm 82* ( think it's 35mm) instead of a Baader eyepiece, ES is really good stuff, for want of a better word!
Zooms, no idea.
Posted 12 December 2012 - 08:46 AM
14mm ES 82 N2
8.8mm ES 82 N2
a good 2x Barlow
Minimalist. High Quality. Reasonable prices.
Posted 12 December 2012 - 08:16 PM
You mean I have to MAKE MY OWN DECISION??
OK. The zoom wins, possibly with the 1.25" (2.25x) barlow that's made for it. For the time being, this will displace fixed length EPs up 24mm. Should be an interesting experiment.
When I've recovered from festive season wallet hemorrhage, I'll decide between a low power 2" EP (to fit M31 or Orion's sword in one go) or an ES24x68 to max out total FoV through a 1.25" EP. The ES EP might cost twice as much by then, but...too bad, so sad.
Hi Matt down under. I like the ES gear but am concerned their 2" EPs are just too massive for my baby dob (6"). As it is, I'm investigating replacing the stock finder with a nice light Rigel Quickfind or 5mW laser, if I can work out how to attach them. I'm aware of laser safety issues.
Clare, I'm a bit nervous about the zoom's narrow-ish 42* AFoV at 24mm too, but forgive it because it gives 70* at 8mm. Plus I'm considering a separate wide field fixed length 24mm. Also, Our eyes' visual acuity is only any good very close to straight ahead, so a wider fixed length EP would mainly be for 'finding', or just 'looking out the window'. Other threads on planet viewing and binary-splitting have very strong, very experienced advocates for ortho's, etc because they are sharp, with little concern about their narrow FoV (compared to some recent EPs).
Does anybody know which EP clamp to buy to fit to the Baader barlow that's made for the zoom, so that it can accept EPs with no filter thread? Can a filter still be used if an EP's thread is used to attach it to the Baader zoom's barlow?
Thank you All, I haven't placed the order yet...Mark
Posted 12 December 2012 - 08:37 PM
Posted 12 December 2012 - 10:23 PM
Yes. This is a great community.
Re the 24-8mm zoom, the shorter the focal length the greater the FoV, more so at the short end. My main concern is the short eye relief at 8mm zoom. About 8.3mm relief (measured by others) rather than 12mm as claimed by Baader. I don't know if that means lots of cleaning of oily marks from eyelash swipes.
There's an enormous Baader zoom thread on this site somewhere (5,000+ posts) but I can't find it just at the moment.
Thanks for the adapter heads up. I know so little about this stuff. I'll have to bend the ear of a sales dude at the (not very) local scope shop.
Posted 12 December 2012 - 10:59 PM