Posts Made By: Richard Low

I am considering to get a 6" apo, and I am wondering what is the visual performance difference for two of the same high-end apo from AP, Tak, TMB etc with similar interferometric test reports but having slightly different strehl ratios, say 0.96 vs. 0.99? Assume the test results are accurate & reliable. Has anyone done a side-by-side observational comparison at high magnification under excellent seeing condition? This is assuming that all other test variables are same & equal, and testing with an optimised optical train, for eg, just using ZAO-II eyepieces and without diagonals in use. Any feedback or comment would be much appreciated.

Vaughn Jett said:

...Does anyone have any recommendations for removing mold from my optical surfaces, or for deterring this sort of thing in the future?

I lived in the wet & humid tropical region where the potential mould on optical glass surface is an on-going threat.

For my previous C8 & current C5+, I have to regularly open up the corrector plate & carefully clean off the fungus with lens-cleaning solution & lens paper. It works well so far

For me, the best deterrence is to keep all optical equipment in a electrical-operated dry cabinet with hygrometer control. And I always get binoculars which are water-proofed & nitrogen-filled, this prevents the internal optical glass surfaces from getting mouldy.

Hope this helps...

I have three: Minolta 7x35, Pentax 8x40, Nikon 10x42. Nowadays I find the 7x35 with 9.3 TFOV very nice for starhopping and general use. Its also light and quite compact.