quality and price tag

[Vince1963]

I have been toying with the idea of up grading for some time now, I hear a lot of good reports on Ortho's, But the question is.. Expensive or cheap?. Are orhto's good across the range? or do you truly get what you pay for?. is there a sacrifice such as ER, chromatic or spherical aberration....I know i wont get wide FOV as some EPs. i'm sure i read somewhere that even cheap ortho's as as good as the expensive.

I'd love to hear your thoughts on this one.

Many thanks

[rowan46]

ortho's are designed to be free of aberrations the trade off is the narrow field of view and very short eye relief at the higher end. They can be used very successfully for deep space observation but need a driven scope and they are at their best in planetary and lunar observation. Like many eyepieces not all ortho's are the same different coatings can give better transmission levels and better views. To an inexperienced observer I doubt the differences would be great but  experienced observers  notice that extra couple of percent. ortho's are a relatively cheap way of getting very good optics but as has been said have their limitations. I have never tried an ortho eyepiece but have read that the top end wide eyepieces come close to ortho performance but with wider field and better eye relief. So to sum up, with an ortho you get top end performance but without the eye relief and wide views a bargain if you have a driven scope and don't need glasses and are prepared to forego wide views.

[Moonshane]

I really like orthos and they provide excellent quality views albeit as stated with short eye relief (not a problem unless you wear glasses) and narrow field. I have obtained great views from both cheaper and expensive ones (although even one of the better versions (BGOs) are around £50 used). Recently though I have preferred the view through wider fields and have bought used older Naglers for about £100 each. These are much more convenient on a manually nudged mount and you don't lose much in image quality if anything.

[Roy Challen]

As rowan46 says, orthoscopic means "free from abberations". The very best orthos are very expensive, but extremely good orthos are not so pricey and are good value for money - if you aren't too bothered about FOV and eye relief. £50 - 60  will get you very good second hand orthos - theres a couple of Baader Genuine orthos on ABS at the mo for less than that. Upto £100 should get you very good new orthos. So - relatively cheap!

[alan potts]

There are a few on astro B&S at the moment, secondhand they are fairly cheap now even for the better ones which are Baader genuine orthoscopics or BGO for short, they now make a Classic range of 3 eyepieces which are also very good, as said small field and I have to be in the mood for them.

Alan

[John]

The ones I'd not be in a rush to buy would be the ones labelled as "Super Abbe Orthos". These come in focal lengths between 4.8mm and 24mm and under a number of different brandings. In all the reports I've read about them they always seem to lag behind the other Abbe Orthos on the market.

If you are comfortable with the Abbe Ortho characteristics with regard to field of view, eye relief and eye lens size then I reckon the Baader GO's, Astro Hutechs and Fujiyama's are very hard to better for around £45-£55 on the used market. Takahashi have recently introduced a range of Abbe Orthoscopics for around £100 each (new) but detailed reports on those are a bit scarce at present. The Baader Classic Orthos are also very good and can be bought new for under £50. I wish there were a few more in that range though.

The older Circle-T or "Volcano Top" orthos can be very good buys for £30 apiece on the used market although I feel their coatings hold them back just a little from the Baader GO's etc. Ergonomically some prefer the conical shaped tops to ease access to the eye relief of the ortho design.

There are a number of out of production orthos from Zeiss and Pentax which are even better than the above but they are very hard to find and command prices well into the £hundreds per eyepiece if you do find them.

[F15Rules]

+1 for John's wise comments. 

I always thought it a shame that Baader type coatings (the best IMO) weren't available on a volcano top design which, ergonomically, I prefer. Then you would have the best of all worlds.

But on a good night, any of the above recommended orthos will deliver crisp, true colour, satisfying images of Moon, Planets and double stars. 

You could get a nice used set at say 5mm, 12.5mm and 18mm for around £100-£150 depending on the brand - and they would last you a lifetime if you want them to :-)

Dave

[spaceboy]

Ortho are worth every penny in my book. BGO's were an amazing eyepiece for the money used. I say were for the simple reason there are plenty of other good quality orthos available these days both new and used that are easily on a par with the BGO.

An advantage with the newer orthos available is that they have a couple more focal lengths to choose from over BGO's and it was for this reason why I went for Fujiyama HD ortho this time around. That and the fact they are near parfocal. This is the one thing that let the BGO down for me as for some reason I always struggled to get the 6mm to focus as while they all ate up inward focus the 6mm seemed to be the worst for it. The Fujiyama focus's much further out so never have any worry of running out of travel even when using filters. I have a couple astro hutech but they are not parfocal and I have had similar issues with having sufficient inward travel focusing them as I did the BGO.

[Vince1963]

Thank you rowan46,  Moonshane, Roy Challen, alan potts, John, F15Rules, spaceboy,.for your valued input, I think i will look closer at the BGO and Fujiyama, If i can pick up some second hand Pentax then i think i'll go that direction but i've made my mind up and ortho's are for me.

Many thanks

Clear skies