Some Physical Orthoscopic Comparisons

[John]

I have a set of the Astro Hutech orthoscopic eyepieces on loan from First Light Optics plus a few Baader Genuine Orthoscopics and a set of the Baader Classic Orthoscopics plus the 32mm Plossl from that range. I've written up some reviews of these in the past which are posted in the reviews section.

Recently I was offered some of the Fujiyama Orthoscopics to try by Glen at Lyra Optic. I was interested in the 4mm as it's the only ortho of that focal length in this "flat topped" style so Glen has kindly loaned me one along with it's 6mm and 25mm siblings.

Poor weather has conspired against me being able to give these any more than the most cursory use under the stars so, until I can rectify that, I thought I'd post some physical descriptions and photos of the eyepieces along with their Baader and Astro Hutech equivalents (or as near as I could get !). 

In terms of overall finish, these eyepieces are very, very similar. The eye lenses seem to be the same diameter, the lens coatings look the same from all angles and react in the same pattern to reflected light. The satin finish of the black bodywork and the chromed barrels seem just the same to me. The similarities extend to the dust caps and boxes which, apart from the branding stickers on the latter seem to be clones of each other as well.

In the 25mm focal length, the black body of the Fujiyama 25mm ortho is around 3mm longer than that of the Astro Hutech and the lens set is around the same distance higher above the shoulder of the eyepiece. In practice this means that the Fujiyama 25mm comes to focus a couple of mm further inwards than the Astro Hutech does. The mounting of the optics seem to be the same design and finish in both eyepieces. Looking into the eye lens at an oblique angle shows that the interior of the eyepieces both utilise blackened micro baffling to control stray light. There is of course no 25mm Baader Genuine Orthoscopic to compare these with.

In the 6mm focal length the Baader GO is the odd one out here, physically at least. As the photo shows the Astro Hutech and Fujiyama share the same black body pattern and size. The chrome barrel on the Fujiyama is around 1mm longer making it appear a little taller overall than the Astro Hutech. Underneath, the Baader again shows a different design to the lens installation wheras the Fujiyama and Astro Hutech approach looks identical. The Baader GO 6mm reaches focus around 8mm further inwards than the other two brands 6mm's. Despite the pattern of concentric ridges moulded into the top of the Baader eyepiece, the eye lenses of all three 6mm orthos looked to be the same diameter and, again the coatings seemed to be consistent in terms of hue and application.

Not having another 4mm orthoscopic available, I could only pair the Fujiyama 4mm ortho for the photo with the Astro Hutech 5mm which is of the same shape and dimensions as the Baader Genuine Ortho 5mm as it happens. The top of the Fujiyama 4mm orthoscopic shares the same general design and proportions as the 6mm in that brand although it's top is actually 1mm smaller in diameter than any of the others, as is the top dust cap which can cause some confusion if you mix it up with the others !. As I think can been seen in the photo, the eye lens of the 4mm Fujiyama is really tiny - I reckon just around 3mm in diameter at most. Finding that small aperture against the dark, smooth eyepiece top, on a dark night might present a challenge I feel ! Otherwise the 4mm Fujiyama is just as well put together and finished as the longer focal lengths discussed here and the field stop seems quite sharply defined, which is nice.

Thats really all that I can say about these until I can give them a proper run out under the stars. The very limited observing I've done so far with them (just a few minutes really) indicates that the Fujiyama's performance is entirely consistent with the Astro Hutech's and the Baader Genuine Ortho's which is unsurprising perhaps, given their other similarities. More thorough testing might reveal some differences however and I'll report what I find 

My thanks are due again to First Light Optics and to Lyra Optic for the loan of these eyepieces.

The photos below are: 

- 25mm's top and bottoms.

- 6mm's top and bottoms.

- 5mm Astro Hutech and 4mm Fujiyama orthos.

Hope you can work out which is which ! 

[nightfisher]

Very nice comparison John, always good to get information on orthoscopic eyepieces, thanks for taking the time to submit this 

[emadmoussa]

Nice report, John.

[Pig]

Excellent report John, I look forward to reading more should the opportunity arise while you have them in your possession

[jetstream]

John,I will be looking to try and split Sirius,which eyepiece would give me a chance using my VX10?Do these types of eyepieces offer excellent contrast on nebula?Specifically the Flame nebula?Thanks for taking the time to do the comparisons and then write it up.

[alan potts]

Nice report John, my that 4mm looks as if it could be difficult to use. I will wish you some clear sky to test these. I know how much time this takes and one night is not enough.

I am doing a report at the moment on the 40mm eyepieces, after seeing the Fujiyama 4mm the Meade 40mm eye-lens looks like a ships port-hole.

Alan

[Damo636]

Nice report John! From near extinction to spoilt for choice in 12 months, long live the ortho!

[John]

Nice report John! From near extinction to spoilt for choice in 12 months, long live the ortho!

Thanks Damo. Yes, reports of their demise were somewhat premature. As were the sudden and short lived price hikes to used ones !

[John]

John,I will be looking to try and split Sirius,which eyepiece would give me a chance using my VX10?Do these types of eyepieces offer excellent contrast on nebula?Specifically the Flame nebula?Thanks for taking the time to do the comparisons and then write it up.

I tend to use them for high power, high contrast viewing such as lunar, planets and binary stars. They show faint DSO's well but I've not noticed them outperforming more complex designs on these to be honest. I may give the 18mm a go on the Horsehead Nebula when Orion is more favourable positioned for me but I did not find the Astro Hutech 25mm a brilliant deep sky eyepiece because of the eye relief / eye positioning issue I describe in my report on it here:

http://stargazerslounge.com/topic/194204-astro-hutech-25mm-orthoscopic-eyepiece-some-notes-and-comments/

As the design of the Fujiyama 25mm is so similar I'm expecting it to have similar characteristics. I might be surprised though 

When I tried a number of 6mm and 5mm eyepieces on Sirius earlier this year with my 12" F/5.3 dob, I found the Baader Genuine Orthoscopic made it just a bit easier to pick out Sirius B than the others as it's control of light scatter and glare from the A star was that little bit better. Next best were the Baader Classic Ortho 6mm and the Pentax XW 5mm and then the 6mm Ethos. The Astro Hutech 6mm seems to match the Baader Genuine Ortho in performance so I imagine that it would be a good Sirius splitting eyepiece too, but I've not actually tried it on that object.

I ought to say that, so far, the 12" Orion Optics dob is the only scope of the many I've owned that has shown me Sirius B. It's not well positioned from the UK and my own back yard has obstructions which restrict the chances I get to view it.

I know that Alan Potts from his base in Bulgaria finds Sirius an easier target.

[bingevader]

I know that Alan Potts from his base in Bulgaria finds Sirius an easier target.

Doesn't he just! We're still waiting for the dates for the Star Party with fresh peaches and walnuts.

Good report as always John.

[Damo636]

Last I heard Alan was just putting the finishing touches to his obsy and will be sending out the invitations as soon as its finished. In fairness, you can't blame the guy for wanting everything to be just right for us!

[alan potts]

I was up this morning at 0500am and outside, there was Sirius, passed it's highest point and no scintillation that I could detect. Now I have all my scopes outside it is much quicker to get them out and they are already cool so not wait time.

I had 120 lts of grape juice to make into Brandy, it is the first time I have done it on my own, I got 20 lts after distillation, no doubt your all thinking it's for the party. I will say this after a glass or two no-one will be able to use a short orthoscopic because they would not be able to find the eyelens.

Sorry for drifting away from topic a little but I was lead astray.

Alan 

[Naemeth]

Nice report, lets hope the weather gets better soon .

[smith]

I have 4 and 7 Fuji and 6mm BGO.

As mechanical part is concern, BGO is far from being parafocal with fuji, as you noticed in this comparo.

I am eager to have your thoughts on optical quality, to know if i should switch my BGO for the Fuji instead.

[Mark at Beaufort]

John a very well written report as always. I was thinking of buying a pair of 25mm ortho EPs to go in my binoviewers to replace my basic Antares plossls. It is interesting what you say about the Astro Hutech 25mm. Although I don't wear glasses I have never really liked EPs with a tight eye relief. The Nagler 3-6 zoom with its 10mm eye relief is as far as I would like to go - perhaps I am missing out on the ortho quality EPs.

When you get some clear skies I look forward to your further review on the Fujiyama orthoscopics.

Mark

[Mark in Macc]

John a very well written report as always. I was thinking of buying a pair of 25mm ortho EPs to go in my binoviewers to replace my basic Antares plossls. It is interesting what you say about the Astro Hutech 25mm. Although I don't wear glasses I have never really liked EPs with a tight eye relief. The Nagler 3-6 zoom with its 10mm eye relief is as far as I would like to go - perhaps I am missing out on the ortho quality EPs.

When you get some clear skies I look forward to your further review on the Fujiyama orthoscopics.

Mark

I have a pair of 25 mm TV plossls that I use with my binos. Very nice indeed and they have soft eyecups to prevent light ingress from the sides. A perfect match for my binos.

[spaceboy]

BUMP