Re: [ATM] Fringe testing Dall Kirkham secondary

[Ken Hunter <atm_ken_hunter@yahoo.com>]

--- Rod Brackenridge <rjbr@lycos.com> wrote:

> Hi Bob,
> 
> Thanks for that.  I would like to check I have
> understood you correctly.  I 
> just tested again.  I started with the bulls-eye
> this time and pressed on the side and the number of
> fringes increased.  Pressing in the centre seems to
> give about the same number of fringes.  It certainly
> doesn't seem to increase.  Therefore the convex is
> longer 

The thing you need to remember is that the number of
fringes will increase as the distance between the
surfaces decreases. If you have 2 curved surfaces and
the bullseye fringes are closer together in the center
then the convex surface is closer to the center of the
concave surface. Just opposite of what you said above.

If the centers touch, you'll have an lot of very close
rings at the center increasing in spacing as you move
out. If the edges touch, the rings will be clustered
around the edge increasing in spacing as you move in.

Thr rings will move towards the decreasing separation.

Ken Hunter




		
__________________________________ 
Do you Yahoo!? 
Check out the new Yahoo! Front Page. 
www.yahoo.com 
 

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