polishing a tec 250mm apo lens

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TheSkyBurner
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polishing a tec 250mm apo lens

Post by TheSkyBurner » Sun Oct 28, 2018 5:57 am


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marktownley
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Re: polishing a tec 250mm apo lens

Post by marktownley » Mon Oct 29, 2018 9:33 am

It's still not very good in the blue even at that price :D :D :D
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Re: polishing a tec 250mm apo lens

Post by TheSkyBurner » Tue Oct 30, 2018 1:29 am

marktownley wrote:
Mon Oct 29, 2018 9:33 am
It's still not very good in the blue even at that price :D :D :D
Yea i learned pretty quick that all modern scopes are russian roulette for blue light/

I have a 60 year old 60mm f/16 and its phenomenal in the blue / violet with its standardized and simple magnesium fluoride coating. I guess when people started to complain about purple / blue fringe in the late 90's all companies opted simultaneously to entirely kill it off.

I dont think anybody realized that blue light was so valuable for imaging. The blue fringe is a must have for venus!

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