Tests on some Classic Orthos
Posted 16 February 2013 - 03:43 PM
Used two different 12.5mm Orthos quite a bit.
UO 12.5mm Vs my unbranded 12.5 Visually the UB has a good bit wider field than the UO. Much to my surprise the Unbranded one(UB) was a tad sharper and had a little less scatter. It is a superb EP.
Used a Meade RGO 10.5mm Vs 12.5 and 9mm UO. Peolpe who claim the RGO is no better than the UO Orthos are not seeing what I am. The RGO has less scatter and incredible definition. A clear step up from the UO ortho.
Unbranded Or 12.5. 46degrees fs10.0mm. el 11.0mm
UO Or 12.5. 39degrees. fs 8.4mm. el 9.8mm
RGO Or 10.5. 43.5 deg. fs 7.9mm. el 9.0mm
UO Or 9mm. 42.5 deg. fs 6.6 mm.
UO Or 7mm. 40.5 deg. fs 4.9mm
The Unbranded ortho has very good coatings, wider field and slightly better performance than the UO 12.5. No contest there..
The Meade RGO 10.5 showed as much detail as the 9mm UO with less scatter and was MUCH better than the UO 12.5.
The UO Orthos are good EPs, But did not perform to the level of the other two EPs
Used my C11 and D&G 5" F12
Posted 16 February 2013 - 06:05 PM
Posted 16 February 2013 - 06:48 PM
Posted 16 February 2013 - 06:59 PM
Posted 16 February 2013 - 07:04 PM
Posted 16 February 2013 - 08:59 PM
Posted 17 February 2013 - 09:17 AM
I thought Circle-T was Towa?
Kohki orthos were made by circle t (Tani) and are the same as the UO. My unmarked one is from another maker. I was told maybe Pentax. Nice as the Circle T 12.5 is and it IS very good, this one is better. Wish I had more FLs.
Shane in grey-zone NM
Posted 17 February 2013 - 12:18 PM
Maybe a member with more knowledge can step in and correct me if I got things wrong.
Posted 17 February 2013 - 01:50 PM
To make a long story short, I continued to use the Orthostar, and it now has become my eyepiece of choice in that focal length. I find the subtle shades of contrast that it's capable of delivering to be nothing short of amazing.
I understand that the Orthostar is a true Abbe Ortho. I was thinking about trying to fill out the set, but would like to keep an open mind. I've heard that the early Meade RGO's were very similar to the Orthostar, but haven't been able to confirm this. I'm wondering if anyone has any experience with this.
Posted 17 February 2013 - 04:09 PM
Posted 17 February 2013 - 05:59 PM
Baader Abbe' orthos.. Are those classics or BGO's? UO sells a Chinese made Abbe' for 50 or 60 bucks. Never used any of those. The BGO is very well regarded but I have no experience there. Used a few Zeiss Abbe's and there is a reason the price of those is so high. They are VERY good.
Posted 17 February 2013 - 06:02 PM
It makes sense the Orthostars and the RGO are at least related. I would say most likely made in the same factory. They have a physical and optical similarity.
Would this be true of all production years, or just the earliest?