[ATM] tde

[Jerry]

The last 1/3 inch is turned up. But just inside it is a turned down zone
that is not quite 1 inch wide. I think image ro1 shows it best. The best way
to visualize it for figuring purposes would be to look at the inside
boundary of the turn down as being high.

Looking at the top of the band to the right of center you see the about 1
1/3 inches in from the edge the band becomes rough and blurred toward the
center but is sharper toward the edge. The blurred rough looking part is
because of a rough surface, but it is relatively straight up and down, so
that it is fairly spherical.

The surface is smoother where the band is more sharply defined. You see that
part is of the band leans toward the center at the top and that is the
turned down zone. Then about the last 1/3 inch to the edge hooks to the
right. That is the turn up. 

See how the light area to the left of that band bulges into the band at
about the top 1/2 of the band? Visualize the light part as the glass and the
edge of the band as the surface, the mirror facing to the right. The bulge
is the high glass that you want to wear down to fix that shape.

I don't think it is over corrected (too much parabola) except in the turned
down zone. Taking the high zone down can fix that.

Jerry






-----Original Message-----
From: lütfü çakmak
 
Hello,

I'm a new member list and a new atm. My mirror is 8"
and f/6,55. My problem is tde and how can I get rid
off them. 7 ronchi photos;

http://www.atmlist.net/contrib/lutfu_cakmak-at-yahoo-dot-com/lutfu/ri1.jpg

ri = Roc inside 1,2,3 to Roc. Roc. And ro = Roc
outside 1,2,3 

Firstly, is this TDE or TUE?
 
Once I know it is tde, and I studied TOT, short
strokes about 3 hours such as suggestions. But I have
not corrected it. I have used standart acculap.

Separately, I think that my mirror done more
paraboloid than be needed it(for f/6,55). What can I
do for this promlem?

There are much knowledge on the internet but
contradictory each other as for me.

Thanks for yours comment.

Lutfu