[ATM] Am I there yet?

[Don Bates <dbates59@yahoo.com>]

I could use some second opinions on the condition of
my mirror from some of the seasoned figuring experts
out there. First, a bit of background:
I completed this mirror (10-inch f/6.6 thin (7/8")
plate glass primary last year. After coating I was
very dis-satisfied with the results. Although the
figure seemed to be very good, I suspected that a
turned edge had snuck past me during final figuring. I
proceeded to strip the coating, and began re-figuring
with an Acculap and sub-micron Cerium. Which brings us
to the present:
After a couple of months of careful work, I think I am
nearing the end. For reference I have put the latest
TEX data below. For Yahoo! users, I have a photo album
showing the Foucault test and Figure Graphs at: 
http://pg.photos.yahoo.com/ph//my_photos
 
Here are my questions:
1)TEX says 1/7.7 PV error at zone 2. However, it seems
to me that zone 4 is worse because it is closer to the
edge. Who is right?
2) TEX shows the figure to be just OUTSIDE the tornado
on the ML graph. How can this be when it is almost 2
times better than the Raleigh criteria?
3) FIGURE says that the mirror is 1/9.54 P-V, with a
Strehl of 0.953. The edge does seem to slope down at
the very edge of the graph. Does this mean a turned
edge?
4) What is the condition of the edge? When I try the
Ronchi at 100 lines, it appears to have hooks sloping
outward at the very edge when outside focal plane. Is
this really a turned edge, or just diffraction effects
at the bevel? I can't seem to get rid of these hooks
no matter what. 
5)If I try to improve this mirror, am I just asking
for trouble? My goal has been to create a really nice
planetary scope, so I am willing to "press on" (pun
intended) for as long as it takes. However, I have
noticed that the longer I figure, the more sleeks
appear... Thanks for any advice!
- Don  

TEXEREAU MIRROR TEST SHEET

Comments: Bates 10-inch primary figure September 08,
2004   Optical diameter: 9.95
Readings per zone: 4
Radius of curvature: 131.25
f/D:  6.60
Diffraction disc: 0.000173804

 1 ZONE                1          2          3        
 4          5      
 2 h(x)              2.3100     3.1800     3.8600    
4.4300     4.9400
 3 h(m)              1.5300     2.7450     3.5200    
4.1450     4.6850
 4 hm**2/R           0.0178     0.0574     0.0944    
0.1309     0.1672
 5 hm/4f             0.0058     0.0105     0.0134    
0.0158     0.0178
 6 D1                0.1525     0.2010     0.2170    
0.2457     0.3095
 7 D2                0.1525     0.2010     0.2170    
0.2457     0.3095
 8 D12               0.1525     0.2010     0.2170    
0.2457     0.3095
 9 D12 -  0.1294     0.0231     0.0716     0.0876    
0.1164     0.1801
10 Lamda c           0.0053     0.0142    -0.0068   
-0.0145     0.0129
11 Lamda f * 1e5       3.07      14.84      -9.12    
-22.97      22.97
12 Lamda f / rho      0.177      0.854     -0.525    
-1.322      1.322
13 u * 1E6            -0.47      -2.26       1.39     
 3.50      -3.50
14 Wavefront          -0.79      -2.82      -1.94     
 0.00      -1.85
	Reference parabola: y = 0.0127021 * x**2 +
-0.00714493
	passing through (  0.75,  0.00) and (  4.43,  0.00)

Maximum wavefront error = 1 / 7.7 wave at zone 2

Results for individual sets of readings:
	Reading set 1: 1 /  5.9 lamda, Max Trans
Abberation=0.92
	Reading set 2: 1 /  4.3 lamda, Max Trans
Abberation=2.78
	Reading set 3: 1 /  8.8 lamda, Max Trans
Abberation=1.29
	Reading set 4: 1 /  9.5 lamda, Max Trans
Abberation=0.85


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