Fujiyama Ortho eyepieces

gregbradley · #1 05-01-2021, 07:03 PM

These eyepieces are for sale in Oz and are quite reasonable in price.

Has anyone had used them that can confirm their high performance?

I have a University Optics 12mm and an Edmunds RKE 15mm which are quite sharp but a narrow field of view. I am not sure I would be happy with too small a field of view but perhaps for optical perfection you have no choice?

Greg.

ab1963 (Andrew) · #2 06-01-2021, 07:38 PM

Had the full set the shorter fl's are tight for er but i really liked the 18 and 24mm, Contrast excellent sharpness excellent fov not what i like and the shorter fl's just too tight er wise for my liking but make no mistake if you can handle the shortfalls they are excellent eyepieces just didn't suit me

Outcast (Carlton) · #3 06-01-2021, 11:22 PM

I owned a set of 6/9/12.5/18/25mm Fujiyama orthos..

IMHO the views were stunningly sharp and full of contrast but, and for me it was a big but, the eye relief was appalling, especially on the shorter FL.

That was the deal breaker for me... I sold them & bought something with better eye relief as I found I just couldn't sit comfortably and view through them for any extended period.

Superb views though if you don't mind FA eye relief...

gregbradley · #4 07-01-2021, 10:44 AM

Yeah that seems to be an issue with Orthos in general unless there are some exceptions
Perhaps one or two might be good to have in the eyepiece kit.
What magnification factor did you find worked best?
Greg

Outcast (Carlton) · #5 07-01-2021, 03:24 PM

In the 8" Sct I owned at the time, the 9 & 12.5mm probably saw the majority of use. 12.5mm was tolerable ER wise, the 9mm was not. I regret moving my 9mm TMB on.

I replaced the shorter FLs with Vixen SLVs but, I'm not liking the rotating eye shields. The longer FL were replaced with Vixen LVWs which I love. I'm chasing 3.5/5/8mm LVWs at the moment.

Cheers

ab1963 (Andrew) · #6 07-01-2021, 08:05 PM

I used mine in a SWED100 and they were fantastic but with the shortfalls already stated i suppose it would have been good to view with them through the FSQ i have now at f8

SkyWatch (Dean) · #7 07-01-2021, 11:25 PM

As an Abbe-Orthoscopic design, their eye relief is ~80% of their FL, which is probably a bit better than a standard plossl. The much sought-after (and way more expensive!!!) Zeiss Abbe-Orthos have similar eye-relief. I have the 18mm (ER 15.2mm) and the 25mm (ER 22.2mm). (The 4mm version has ER of 3.4mm...) They give excellent sharpness, contrast and brightness, but have only a 42-degree AFOV. The 25mm in particular is one of my favourite eyepieces; it has amazing clarity.

I find they compare extremely well with my 18mm Radian and 27mm Panoptic respectively: in fact they are possibly a bit brighter and offer better contrast. If you want to closely examine an object and get the maximum contrast for fine detail they are excellent, but they are not for those who want to enjoy a broader view.

I think you will find that most short FL eyepieces with longer ER (eg: Orion "edge-on planetaries" and other re-branded Long Perng) have in-built barlows, so extra glass and therefore less light through-put.

- Dean

N1 (Mirko) · #8 08-01-2021, 07:45 AM

I have all FLs except the 12.5 and 25, and they are great performers, especially at f/8 or slower. They have the typical Abbe design quirks but all, including the the 4mm, compensate for that by sharpness and contrast. These are designed for planet observing, so the short eye relief issue is kind of a moot point because as the field darkens at higher mags, seeing the field stop becomes less easy, or important for that matter, solar and lunar being the only two exceptions. That said, they do work well for DSO, when one wants to tease out detail other designs might not show as well.

But: in a slow optic, they probably won't be a significant improvement over the RKE.

Tropo-Bob (Bob) · #9 08-01-2021, 09:07 AM

I have had several 4mm orthos over the years, but never liked any of them. Their eye-relief is just too small. I do have a 5mm KK and am happy with it.

My favourite Ortho is a 9mm. The 9mm can easily be converted into a 4.5 or 3mm with a barlow. Indeed, I used a 9mm with a 3X barlow to obtain my best views of Mars this year.

mandragara (Richard) · #10 22-01-2021, 05:29 PM

I have a fairly fast f/5 Dob. Considering getting one of these Fujiyama eyepieces to see what this famed sharpness is like.

Does using a Powermate style focal extender compromise their sharpness? To me a 25mm Ortho + a 5x focal extender for planetary viewing might be the way to go.

I'd be comparing it to a 25mm Televue Plossl, do you think the difference would be noticeable? Or are the TV plossl's just too well corrected?

SkyWatch (Dean) · #11 23-01-2021, 10:41 AM

Quote:

Originally Posted by mandragara

I have a fairly fast f/5 Dob. Considering getting one of these Fujiyama eyepieces to see what this famed sharpness is like.

Does using a Powermate style focal extender compromise their sharpness? To me a 25mm Ortho + a 5x focal extender for planetary viewing might be the way to go.

I'd be comparing it to a 25mm Televue Plossl, do you think the difference would be noticeable? Or are the TV plossl's just too well corrected?

The 25mm works very well on my f5 dob. I haven't tried it with a 5x extender, but I can't see any issues. Remember though that the view can never be better than the weakest link in the optical path allows, so if it is a lower quality extender the view will reflect that.

I doubt that you would see much difference compared with the TV25, apart from a slightly smaller field. The Fuji may offer slightly higher contrast. I don't have the TV25, but I have a TV32 which is excellent; although certainly not any sharper than the 25mm Fuji, which remains my favourite for clarity of the view.

One thing is for sure, you wont have any problem with eye relief! As noted before, this design usually has better eye relief than the plossl design; and in this case it is 22mm vs 17mm for the TV. This will be even greater when mated with a barlow.

bigjoe (JOSEPH) · #12 23-01-2021, 11:44 AM

Quote:

Originally Posted by Tropo-Bob

I have had several 4mm orthos over the years, but never liked any of them. Their eye-relief is just too small. I do have a 5mm KK and am happy with it.

My favourite Ortho is a 9mm. The 9mm can easily be converted into a 4.5 or 3mm with a barlow. Indeed, I used a 9mm with a 3X barlow to obtain my best views of Mars this year.

+1 for good Abbes Bob ..most of us are too obsessed with widefields and their compromises however small..9,12.5 and 18 are great barlowed.
Bigjoe.

gregbradley · #13 23-01-2021, 12:29 PM

I tried a new Edmunds Optics 28mm RKE last night and finally managed to get the quirky yet quite comfortable rubber eyecup on.

Its a very nice view and the widefield nature of 28mm negates the smaller FOV.

I have a 4.6mm University Optics and its horrible to look through. Floaters and like looking through a straw yet the view did not appear to be any better than wider eyepieces. The 3.5mm Nagler T6 on the other

I got a 7.5mm TMBii Planetary. Cost me all of $57 or so. Wow, now that is a good view and its as cheap as chips. 58 degree view, hardly any colour on the lunar limb and extremely sharp, high transmission and detailed. Very happy with that "major investment".

I have a new 18mm Fujiyama Ortho coming to me next week. I can post my impressions. Marcelo from Astrodog said Fujiyama are working on some longer focal length versions of these eyepieces as well. So that could be good later in the year.

Greg