Astro Hutech Japanese Orthoscopic Eyepieces

[webboid]

I recently purchase two of these orthos from FLO to compliment my ever growing collection of oculars & thought I would share my experiences with them.

Prompted by John's excellent review/comparison & tempted by the reasonable price for these, I took the plunge & ordered the 5mm & 6mm variants. They swiftly arrived, as is usual from FLO, a few days later. My primary intention was to use them with a borrowed (probably soon to purchase) Intes Micro M703 deluxe. This would be very high power 297x & 356x for Lunar & planetary observing. I have only had one chance to try them with that scope & the seeing was not too good but some detail was shown on Mars. Since 23 May I have had 4 observing sessions, two with the dob & 2 with the ST102 & have tried these out on various targets.

Early last night, just after sunset, I was having a look at the Moon with the ST102 (5mm gives 100x & 6mm gives 83x). The views were very good. To my relatively inexperienced eyes detail was sharp & good contrast. I kept making comparisons with barlowed Naglers & the orthos seemed a little better! Later I swapped to the 12" dob (5mm gives 237x & 6mm gives 197x) & was very much impressed viewing several globs (M13, M92, M10, M12, M14, M56, M5, M3). The whole FOV was immersed by the bigger targets revealing numerous pin point stars. The highlight was Saturn, the 6mm view was quite superb. The Cassini division was clear & sharp the whole way round & colouration on the surface distinct.

A few days earlier I was observing Mars with the dob. The orthos once again showing good detail & contrast differences on it's surface. Waiting for steady seeing the view was stunning & the best I have seen.

On the 23 May I was using the refractor. Although getting rather low now Jupiter showed some detail on the bands & they stood out well. I split the double double at 100x a first for me with that scope. M13 was resolving a few stars which was also a first in that scope. Barlowing the orthos Saturn revealed part way round it's Cassini division & some subtle shading.

I had some reservations about the tight eye relief, 4 & 4.9mm respectively, but this did not cause any problems. I found the viewing quite comfortable & always sit while observing anyway, which helps too. So I am extremely happy in their performance with the dob & refractor. Looking forward to using them on the Moon with the Mak.

Now I am tempted to buy some more but don't think it is sensible to double up on the same focal lengths surely?

[YKSE]

Really nice write up

When the short eye reliefs in short Orthos are not an isssue, good orthos do give the best performance per quid, IMHO.

[alan potts]

Nice write up on the orthos Paul, I have the 12.5mm and find that very good, the others I have are BGO's though I do no not have the 5mm. I like the choice of scope and if I were you I would try to acquire it, I have the 180mm SW which I believe is a little smaller. The Intes are very solid.

I tested the Hutech I have with the 13mm Nagler I used to have and tend to agree the BGO is a little better, but thats all. You must always consider the design and skill required to get that almost as good across a much large FOV and get better eye-relief, neat trick in my books. The other thing I find and I guess I am doing this more than most, it is very hard to look at two completely different size FOV's even if the F/L is much the same, it appears you almost have a shorter focal length eyepiece in the scope than you really have, refering to the Hutech having a smaller field. It can really play tricks with the eyes

Good luck with the scope and anymore forthcoming Astro Hutechs.

Alan

[webboid]

Thanks for the comments.

Fair point Alan regarding FOV when comparing. The Nagler being almost twice that of the ortho! But I was trying hard to look at the finer detail around Mare Crisium as a comparison & the small ripples, craters & riles stood out better & sharper with the orthos in my view & so I did not notice the larger field. 

I have first refusal on the Mak & I am very pleased with it's performance in the few sessions I have had so far. Looking to give it a good try out on the Moon, weather permitting, in the next few weeks to confirm my decission to buy it.

[alan potts]

Paul,

These are fairly rare secondhand and it is the scope I wanted but was not going to wait almost a year. Alan Potts top tip, buy!

Yes it is not easy with the FOV, but fully agree the BGO/Hutech edges it. For me though the Nagler range, and I have had a few, are not my favourite on the Moon.

Alan

[webboid]

Alan

Interesting that you say the Naglers are not your favourite on the Moon. Care to eloborate?

[alan potts]

Paul,

I have had or still got 31mm 26mm, 20mm,16mm,13mm 11mm 9mm & 7mm. all show a degree of pincushion distortion, it was the main reason I got rid of the 26mm, even though I didn't normally use for the Moon, when you place the Moon at the edge of field the view is rather odd in my opioion as it changes shape. Naglers are great eyepieces don't get me wrong but I just don't like them on the Moon. If I am viewing the Moon which I do now more than ever before I like Delos orthos and Ethos which are flat field. Even Panoptics which I use a good deal have pincushion. The 35mm which I probably use more than any other is a finder but in the Mak 180mm starts to deliver mid-range power. I know the Moon is not exactly round but I like it to look like it is in my eyepieces.

Alan

[webboid]

Thank for that insight Alan. I will look out for that when I start looking at the Moon with the Mak. I like my Naglers but I am now a fan of the orthos & may well get some more.

[John]

Nice write up Paul 

In my opinion, the optical performance of the Baader GO's, Astro Hutech's and Fujiyama orthos is identical. There are some differences in the focal plane positioning across the Astro Hutech range though which can be a little frustrating.

[Saganite]

Hi Paul,

A very enjoyable write up.

I also tried otho's after reading various threads, and I like them very much. I don't find the eye relief

a problem at all, at least not down to 6mm focal length so far.My collection so far includes Circle T, BGO, Universal Optics,

Astro Hutech, and Meade Research Grade, in focal lengths from 6mm to 18mm, and they all  have their moment

in the focuser, dependant on the object, and the 'seeing'.

Many questions have been posed wthin this forum, as to the merits of one make over the others, but it is pretty clear

to me that you need experienced eyes to notice a great deal of difference. They are all great.

Good luck with your collection, and , of course, your observing.