[ATM] TDE (That Darned Edge)

["Meeks Robert-PT1784" <bob.meeks@motorola.com>]

Hello - I've uploaded a not-so-good picture of a Ronchi pattern.
Details below, but it shows a TDE.  A few days ago, I had a seriously
deep center hole and a TDE.  I thought that fixing one would help the
other.  After about 5-6 hours, the center hole is mostly gone (you can
still barely see it when inside ROC), which means that I've taken out a
fair amount of glass to reduce the rest of the surface around the hole,
but the edge has not budged.  I suspect that my stroke or lap or
whatever simply continues to perpetuate the turned edge.  I used mostly
TOT, slightly offset, and with a little pressure on the inside edge of
the tool (not the part that was overhanging) to focus in on the area
between the center and edge.
 
This is my first mirror, and I've heard several of you indicate that
*most* mirrors have some amount of edge defect.  I'm inclined to finish
the figuring (slightly over-corrected at this point), mask off the edge
and move on.  But I have no basis of comparison to be able to say
whether this is a "bad" TDE or a "little" TDE.  It's hard to tell how
much is bad edge and how much is diffraction.
 
I know this is subjective, but if this was your mirror would you invest
the time to work on the edge or is this amount of TDE "acceptable"
(assuming I masked it off)?  
 
Here are the link and relevant facts:
 
http://www.atmlist.net/contrib/bob-dot-meeks-at-motorola-dot-com/IMG_310
9.jpg
Diameter:  8 inches
ROC:  122 inches
This picture was taken .5 inches outside ROC
 
Thanks for your help,
Bob
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