Posted 22 April 2014 - 01:14 PM
Posted 22 April 2014 - 02:38 PM
Posted 22 April 2014 - 03:19 PM
In Europe, they never really left the mainstream scene at all. Every visual observer I know/knew seem(ed) to have some, even if they also owned more recent designs. Zeiss sold loads of them, as did Takahashi, Vixen and Tani Optics (same as UO orthos).
Visual observers over here never forgot what a good ortho is capable of, certainly not the planetary observers, but also to some degree deep-sky specialists.
Perhaps this is the influence of marketing and conspicuous consumption, things we have no shortage of on this side of the Atlantic.
Up until about 5 years ago I was caught up in the marketing spell too. Rediscovery is nice too.
Posted 22 April 2014 - 04:24 PM
Posted 22 April 2014 - 09:26 PM
But I was looking at a used one for sale.
"Celestron by Vixen 7mm Ortho 1.25" Eyepiece Orthoscopic Circle V Japan" for $42 shipped
1) Is this a good eyepiece?
2) If so, is this a good price?
I'm interested in this 7mm for planetary detail
My scope is a 8" Dobs F/6 Orion XT8 1200FL
Posted 22 April 2014 - 09:39 PM
In short, if you are wanting to try an Ortho in the classic sense, keep looking.
Posted 22 April 2014 - 09:59 PM
I thought so. I knew some of the orthos were two doublets under a volcano top' but did not know enough but did not know which ones.
I,ll keep looking
Posted 23 April 2014 - 01:30 AM
I use an BGO 7mm in my A-P Traveler wich has almost the same specs as your CFF telescope. I use this ep when i want the last details out of the planets. This BGO can do that with my telescope and not only with the APO, it does a really good job in SCT's as well.
In a planet observing session i use first some TV Radian's for long periods of observing because of the bigger ER. When i have the details in my mind, then i take the BGO for a shorter time to squeeze the last details.
So Ortho's will work with your telescope. But they are not very comfortable for very long sessions imo.
How is your CFF doing btw?
Posted 23 April 2014 - 03:57 AM
Orthos - the "buggy whips" of the eyepiece world. Damn fine buggy whips they are, too. But who whips an automobile?
I sure would like to whip my car once in a while, when it acts up.
But I think the analogy is somewhat flawed. Orthos are still mighty fine eyepieces, even if more wide field designs exist. They are by no means made nearly useless by modern eyepieces, unlike the horse, which is not supported by modern infrastructure. I used orthos for much of my observing for many years and were perfectly happy with them. I now use wide-field designs for my deep-sky observing, but in my binoviewer, I still use narrow field eyepieces with the greatest possible image definition. I used to use UO orthos, but currently use 25mm Zeiss microscope eyepieces (a 1-2-1 König variety) and 40mm TS Superviews (probably plössls). I basically only use the 40mm TS Superviews because 40mm orthos were not available at the time I bought them. I am now looking into getting a pair of 32mm orthos.
Posted 23 April 2014 - 05:48 AM
Suggested that I should also try some, orthos to get some perfect views.i think i will try the new Fujiyama orthos, of Japanese make but cheaper than Tak.
Yes the CFF is great, and stubby,but its heavier, than your AP, I feel.
Posted 23 April 2014 - 08:12 AM
For an F6, I would say no. It is a little too fast and the point of a fast scope is the wide field. Orthos have a narrow FOV. Orthos IMO are for long focal length scopes and planetary viewing. YMMV
For high powers on my FCT 100/640 Fluorite triplet, I'm exclusively using the Tak Hi-Orthos 4mm (160x) and 2.8mm (230x) with 0.96"-barrel.
Both are of 1-3--2 design (Ortho plus integrated matched Barlow or Smyth-lens). => In fact, the 1-3-part of the "2.8" is actually a 5mm and the "4" is a 7mm ortho, both including their own Barlow.
Orthos are especially good if used with scope focal-lengths longer than f/8 and that's exactly what these built-in Barlow/Smyth-lenses do for my f/6.4 relatively short-focus-apo! Additionally, they also prolong the eye-relief plus flatten the field => pinpoint stars to the edge.
These eyepieces were developped by Takahashi for providing comfortable high magnifications to their short-focus FCT apochromatic refractors.
On my own FCT, these have turned out to be much easier to use than good standard orthos and (thanks to the prolonged telescopic f.l.) optically at least the same good as any of them.
In good seeing, the 2.8-HiOr (230x) shows all of the Jovian's detail that's optically accessible to any 4-incher, and it does so to perfection: No loss of (even low contrast-) detail compared to 160x! - Well, also no real gain: Everything (not more and not less) that is visible at 160x can also be seen at 230x, but more extended and therefore a little easier.
My wonderful (though non-ortho) Pentax XO-5.1 OTOH, compared to these two and also in excellent seeing, cannot quite provide my eyes at mag 125x with the same information of Jovian surface Detail in the same scope. => This magnification seems just to be a bit below (Jovian) optimum, which I rather consider to be the HiOr-4's pupil-diameter of 0.63mm than the XO's 0.8mm.
For Saturn and Mars in excellent seeing, I prefer the 2.8mm (230x).
In bino-mode, planets appear definitely bigger than at same magnification in mono-mode. Therefore, with my TV-Binoview plus 2x Barlow/glasspath-corrector, I'm exclusively using two 9mm Volcano-Top-Orthos (Tani=U.O.). The resulting 142x (0.7mm) seems to be optimum for stereo-viewing Jupiter with this telescope.
Posted 23 April 2014 - 09:54 PM
Posted 23 April 2014 - 11:41 PM
Posted 23 April 2014 - 11:43 PM
A fine eyepiece - I have used them for 50yrs.
Posted 24 April 2014 - 10:45 AM
Posted 25 April 2014 - 03:05 PM
Posted 25 April 2014 - 05:05 PM
Posted 26 April 2014 - 12:25 AM
and if you count slightly modified versions of the above, also Harry Siebert and Takahashi (Hi-LE)
Posted 26 April 2014 - 08:38 AM
Posted 26 April 2014 - 08:44 AM
Posted 26 April 2014 - 08:56 AM