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View Full Version here: : APO colour skewing from internal paints


gregbradley
14-12-2011, 08:18 PM
Percy Muir has done some interesting work somewhat in conjunction with my observation on several scopes performance about colour.

It turns out the internal black paint used by manufacturers can cause your beautiful APO lens that has no colour defects to have a slight bias to one colour or another.

His handling was to test the scope as-is and those that showed a slight bias he installed royal velvet flocking to the inside of the tube and tested it again. He found then no colour bias at all.

I am not sure I would be willing to flock the insides of my APOs but I post the info for those who may be willing to do it for that last bit of performance.

For the record it came up that Krylon Matt Black was the most matt black paint around. It has some ridiculously low reflection percentage (from memory 0.1%).

Its a US paint.

Greg.