35 
Table 3 
Summary of Data Obtained on Covogon 12 inch Lens, f/4. 
B. Broad Spectral Band (with Wratten 21) 
Angular 
Field 
Focal 
Position 
Line 
Orientation 
1 
PTB 
2 
RAF 
3 
BBC 
4 
IGR 
5 
SIRA 
6 
ITFK 
7 
QTI 
8 
NBS 
1. 
0° 
0.00mm 
T 
X 
X 
X 
X 
X 
X 
X 
2. 
R 
X 
X 
X 
X 
X 
0 
c 
3. 
0.10mm 
T 
X 
A 
A 
X 
X 
X 
X 
4. 
R 
0 
X 
X 
X 
X 
0 
0 
5. 
-0.10mm 
T 
X 
\r 
A 
X 
X 
X 
X 
X 
6. 
R 
0 
X 
Tr 
A 
X 
X 
0 
0 
7. 
0.20mm 
T 
X 
X 
X 
0 
X 
X 
X 
8. 
R 
0 
X 
X 
0 
0 
0 
Ü 
9. 
-0.20mm 
T 
X 
X 
X 
0 
X 
X 
X 
10. 
R 
0 
X 
X 
0 
0 
0 
0 
11. 
0.30 mm 
T 
X 
V 
A 
X 
G 
X 
X 
X 
12. 
R 
0 
A 
X 
Ü 
0 
0 
0 
13. 
-0.30mm 
T 
X 
X 
X 
0 
X 
X 
X 
14. 
R 
0 
X 
X 
0 
0 
0 
0 
15. 
+15° 
0.00mm 
T 
A 
0 
X 
A 
X 
0 
X 
16. 
R 
X 
0 
0 
X 
X 
0 
0 
17. 
0.10mm 
T 
X 
0 
X 
A 
X 
Ü 
X 
18. 
R 
X 
0 
0 
X 
X 
0 
0 
19. 
0.10mm 
T 
X 
0 
X 
X 
X 
0 
X 
20. 
R 
X 
0 
0 
X 
X 
0 
0 
21. 
-15° 
0.00mm 
T 
X 
0 
X 
X 
0 
0 
X 
22. 
R 
X 
0 
0 
X 
0 
0 
0 
23. 
0.10mm 
T 
X 
0 
A 
A 
0 
G 
X 
24. 
R 
rr 
A 
0 
0 
X 
0 
0 
c 
25. 
-0.10mm 
T 
X 
0 
X 
X 
0 
0 
X 
26. 
R 
X 
0 
0 
X 
G 
0 
0 
27. 
+15° 
Best Actual T 
Focus 
X 
0 
X 
0 
X 
X 
X