4 replies to this topic

[PawPaw]

I was inspired to write this brief history on Goto Optical Company’s Mark-X era products. The source material I use here is available from several sites on the internet. My objective was to bring those resources together in one document. I want to thank the following persons who contributed and assisted in the research. Goto Telescope Company LTD. For their permission to use documents and pictures. Especially to the President Mr. Makoto Kasahara. Mr. Dave Trott for the inspiration and his patient assistance on translation and context. Mr. Stewart Squires for his exceptional research and expertise on Goto’s Optical history. Mr. Koji Matsumoto for his kind permission to include his insight and writings. Finally to Sapporo Observatory’s staff for their support and confirmation of their 20cm Goto ED-Apo telescope.

Click here to view the article

[aoirotukiko]

Hi

 

The introduction of Goto's apochromatic objective lenses into the market was a major transformation.
It was too expensive for me at the time, so I didn't buy it.

Prior to Goto's development of the apochromat (triplet type), Canon had a utility model patent for objective lenses for the manufacture of astronomical telescopes.
And Takahashi commercialized a triplet type semi-apochromat to overcome the achromat. Takahashi was able to shorten the focal length by adopting triplets.
After the development of Apochromat by Goto, Asahi Optical (Pentax) sells triplet type products.
Each has its own characteristics, and I find each one attractive.
Advances in computers and the development of new software have made lens design possible.

[PawPaw]

Some new information has come to light regarding when Goto started working on their Apochromat designs.  There is an ad by Goto in the 1976.9 Tenmon catalog states they started working and testing a new type of glass from Schott starting in 1973 but eventually chose  Ohara glass.  I cannot add the document here so  I will post it on this thread:  

 

https://www.cloudyni...erings-in-1976/

 

Don

[mikemarotta]

This makes me wonder why ED apochromatics did not become industry standard 40 years ago, 30 at the latest, and why we even bother with achromatics at all.

 

Thanks for your hard work and great research and reporting.

 

Mike M.

[Scott99]

They made nice stuff!  The blue EQ mount is particularly nice.  Too bad Goto wasn't more widely distributed in the USA