Hi again, Its another top night here so I will do a few hours of imaging of M16 and M20. Thanks for all the help so far, I shall get into that new program tomorrow and see how I go. I gave the program I have couder32 and inputted my readings and that gave me a similar result of about 1/7 wave error. With a bit of playing with the numbers in zone 2 and 3 the error would drop to 1/30 wave error. So if my readings are right if I can reduce the outer zones I will have a great mirror.
But I will do another 6 readings like you said before I try to correct anything. I think I will give that ago and will be happy with 1/10 mirror!!!!.
Can I ask a silly question? with the shadows and reading them with the mask I have been moving the knife back till both windows fade exactly the same when the knife enters the path and if one window fades or lightens slightly when the knife cuts the beam then I adjust the knife carriage forwards or back again till I cannot see any difference..is this correct?..just checking..
Oh my tester is similar to texereau`s one with fixed source.
If you want the next lot of readings let me know and I will post them and go from there....
Cheers Gary