Re: [ATM] Ronchi testing

["Bob May" <bobmay@nethere.com>]

Not much that I can say about that, Jerry.  I tend to test near the
extinction area as using a slitless tester in room lighting (I'm working in
a garage where the roof has skylights and there is light coming in also at
the edges and the open doors) and sometimes have to put up a shield for the
shorter FL mirrors as the light just doesn't cover quite right at the higher
light levels.  In addition, I use a video camera (cheap security camera) to
do the imaging of the mirror as this not only allows me to do the testing in
comfort but the brightness of the mask can be compared to that of the zone
so that the eye can see things even more easily.
For best results, do your testing in the dark or with a nightlight in the
room at night and I think you will see things a lot easier.
When I was in a classroom at the University, I had a 40W bulb lit across the
room to get the right level of light on the mask for beautiful results.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net


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