Re: [ATM] Re: Help with Richfield mirror

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

What I'm seeing is a hole in the middle plus a bit of zoniness, probably
from too even a stroke.
I'd try to go back towards a sphere with a TOT 1/.4 or so stroke and try
again.  The thing that is important here is to make sure that the hole goes
away as the edge is also hit with the new curve.
I also find that the readings are not quite "real" as there is too many
digits in the numbers.  Accuracy to about .002" is about as best as you
probably should be getting for balance of the shades of gray with that
mirror without getting finicky about the readings.
If you are using a true Couder Mask (all 6 zones on one mask), I'd suggest
also that you do a mask for each zone as this will simplify the possibility
of matching zonal opening intensities a lot easier.  A nice compromise is to
make two masks with alternating zones on each, odd on one and even on the
other.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net


_______________________________________________
ATM mailing list http://www.atmlist.net/