Hi All,
Could anyone in-the-know please advise me on which 1¼" ep design/type requires the least amount of in-travel/back-focus for focusing on targets at infinity?
Of the 1¼" eps I currently have; Nagler T-6s, all the 1¼"-only panoptics, couple of radians, Pentax XLs, Vixen LVWs, several Celestron ultimas, axioms and excels, several orthos, various plössls, and various other eps like Siebert standards & ultras, I find that the Nagler T-6s seem to have the least amount of in-travel/back-focus necessary to attain focus.
To satisfy everyone's curiosity, my reason for this inquiry is that I have a custom made adapter, which I bought from someone on AM, for my Apo spotting scope, which allows the use of standard 1¼" eps, and I'm trying to find a line or design of eps that'll allow reaching focus at infinity, as well as close-up targets for nature study.
I haven't had an oportunity to try anything out on the night-sky yet, but have found that when using the T-6s on a brick wall about 100' away, I can reach focus with some focus room, towards infinity focus, still available. Whereas, using eps like the panoptics, radians, and long fl orthos leaves very little focus travel towards infinity. While others; ultimas, axioms, Siebert's, short fl orthos, etc., won't focus on anything further than about 40', or so, away.
I'm sure some of you may think this is a hopeless, foolhardy venture on my part, but the crispness, detail, and total lack of any CA(when looking at the edges of the bricks and a window and it's various sharp-edged components), I could see in that brick wall, using say my 2.5 & 3.5mm T-6s, or my 3 & 4mm radians, approx 176X-110X magnification, was astounding. The tiny flakes of loose paint on the window-sill, and the tiny sand-grains/pebbles in the mortar of the brick, at about 176X made it look like the lunar surface, with shadows and brightly lit peaks. I could even see detail and color variation in the larger individual sand-grains. 8O
If I could just get a few eps under about 7mm fl(the highest power/shortest fl available with the scope's stock zoom ep) to reach focus at infinity, I think the images of the night-sky, moon, and planets, would be incredible.
So, what are some other ep designs, which require significantly less focuser in-travel or back-focus, than most others?
Thanks for any info anyone may be able to provide me. 8)
P.S.- I haven't tried barlows or powermates yet either, that's next!!
Thanks again,
Joe D. 8)
Edit:forgot signature :S
Could anyone in-the-know please advise me on which 1¼" ep design/type requires the least amount of in-travel/back-focus for focusing on targets at infinity?
Of the 1¼" eps I currently have; Nagler T-6s, all the 1¼"-only panoptics, couple of radians, Pentax XLs, Vixen LVWs, several Celestron ultimas, axioms and excels, several orthos, various plössls, and various other eps like Siebert standards & ultras, I find that the Nagler T-6s seem to have the least amount of in-travel/back-focus necessary to attain focus.
To satisfy everyone's curiosity, my reason for this inquiry is that I have a custom made adapter, which I bought from someone on AM, for my Apo spotting scope, which allows the use of standard 1¼" eps, and I'm trying to find a line or design of eps that'll allow reaching focus at infinity, as well as close-up targets for nature study.
I haven't had an oportunity to try anything out on the night-sky yet, but have found that when using the T-6s on a brick wall about 100' away, I can reach focus with some focus room, towards infinity focus, still available. Whereas, using eps like the panoptics, radians, and long fl orthos leaves very little focus travel towards infinity. While others; ultimas, axioms, Siebert's, short fl orthos, etc., won't focus on anything further than about 40', or so, away.
I'm sure some of you may think this is a hopeless, foolhardy venture on my part, but the crispness, detail, and total lack of any CA(when looking at the edges of the bricks and a window and it's various sharp-edged components), I could see in that brick wall, using say my 2.5 & 3.5mm T-6s, or my 3 & 4mm radians, approx 176X-110X magnification, was astounding. The tiny flakes of loose paint on the window-sill, and the tiny sand-grains/pebbles in the mortar of the brick, at about 176X made it look like the lunar surface, with shadows and brightly lit peaks. I could even see detail and color variation in the larger individual sand-grains. 8O
If I could just get a few eps under about 7mm fl(the highest power/shortest fl available with the scope's stock zoom ep) to reach focus at infinity, I think the images of the night-sky, moon, and planets, would be incredible.
So, what are some other ep designs, which require significantly less focuser in-travel or back-focus, than most others?
Thanks for any info anyone may be able to provide me. 8)
P.S.- I haven't tried barlows or powermates yet either, that's next!!
Thanks again,
Joe D. 8)
Edit:forgot signature :S
