Ideas needed for an eyepiece/s suitable for positive projection imaging

[[1ponders] (Paul)]

For positive eyepiece projection imaging I've been using a Celestron 15mm Omni eyepiece. While it doesn't show as much chromatic aberration as simply using my Omni barlow, it is still very obvious. Rather than spend a few hundred on a Powermate I'm interested looking at a range of eyepieces that I could use rather than the Celestron I am currently using.

A couple of simple requirements;
1. Must fit inside a variable tele-extender. That means slim design with no bulky waists or chunky rubber sleeves. Celestron silver tops fit in np, Meade 4000 (below 26mm. 26 might fit but it would be a tight fit).

2. Preferably no chromatic aberration, though small amounts can be processed out if there is no other choice.

3. FLs, 10mm, 15mm, 20mm, 32/35mm. The one needed atm is 20 or 15mm. Field of View is not critical for this application, though it would be nice to be able to use it for visual work

4. Sharp!

5. Value for money.

6. I'd like to be able to get the first eyepiece either before the Qld astrofest or while I'm there

I was thinking along the lines of some good Orthoscopics, but I am very open to suggestions.

[gbeal]

Don't be scrooge, buy the Powermate mate.
OK, I have been known to promote the E/P Projection idea, and this was partly from cost, but also practicality.
In seeing conditions that will not allow the 5x Powermate I sometimes "throttle back" by using E/P/P, and use the Zeiss orthos I have. They don't exactly fulfill the #5 criteria though.
Having them in a set, (25, 16, 12.5, 10, 8, 6, & 4mm) allows a near infinite change of image scale, with the O-8mm giving about what the 5x Powermate gives. So, if the seeing won't allow the 5x, I may try the O-10mm or O-12.5mm.
I would think that the University Optics Orthos would be a good thing to try. But I stress, try them first, if you can, as with any eyepiece, 'cos not all eyepieces work well for projection. (not sure why).

[[1ponders] (Paul)]

Thanks Gary. Yeah I was thinking of your Zeiss as I was typing my first post . I use a variable extender with my eyepiece so I get pretty much from 2.5X barlow size image to covering 460+pixel size as it is, so lots of eyepieces aren't necessary. It's a great way to go if you need to change your focal length quickly and easily. I much prefer it to barlowing.

[CoombellKid]

Paul, I have the 18mm 12mm 9mm and 7mm U/O HD's Ortho's your
more than welcome to try them at Astrofest to see if that's going
to do it for you. But they are not for sale, John B was looking at
selling his awhile back.

regards,CS

Rob


regards,CS

Rob

[[1ponders] (Paul)]

Cheers Rob, thanks for that, much appreciated. The 18mm might just work out fine for that intermediate FL

[CoombellKid]

Np's Paul, We'll be rockin up on Tuesday. So you can have a few days to
play around with them.

regards,CS

Rob

[ausastronomer (John Bambury)]

Originally Posted by CoombellKid

Paul, I have the 18mm 12mm 9mm and 7mm U/O HD's Ortho's. John B was looking at selling his awhile back.

Rob

Well I thought about it but only for a fleeting moment. No longer an option.

I don't need the money and they offer some in between focal lengths that I don't have with the Pentax XW's. In addition to that, my 9yr old son will have his own telescope fairly soon and I plan to give him the set of HD orthos to use with it. Besides all that, I just like them for what they are, a small simple eyepiece that provides lovely bright, sharp, contrasty images for both planetary and DSO work.

CS-John B

[[1ponders] (Paul)]

np John. I'd like to hear your ideas though on them, or any others that might be good for the job I want to put them to.

[CoombellKid]

Originally Posted by ausastronomer

Besides all that, I just like them for what they are, a small simple eyepiece that provides lovely bright, sharp, contrasty images for both planetary and DSO work.

CS-John B

That's exactly why mine were taken off sale last year. I tend to not use
them allot, but when I do, I say to myself... why did I ever think of trying
to sell them. I feel they are probably one of the most under rated ep's. But
then again that's just my opinion and may not be an educated one. I will
be giving them as well as my 30mm SV (which I dont use anymore, the
20mm t5 has superseeded it) to my son who is also called Jake

FWIW Paul, I'm looking forward to seeing how the U/O HD's go in a PST.
I'll be picking mine up on Friday at Astrofest.

regards,CS sunny days

Rob