Hola Mike...I'm going to regret knowing you someday
"This is the MTF I achieved for a 650mm f/1.5 Hamiltonian astrograph with the 3-element
corrector as shown in Preston's plot above. Plenty of modulation out to 100 cy/mm (equal to 5µm pixels).
These Hamiltonians are the way to go for very fast astrographs with moderate field coverage."
I am guessing that the Corrector glass is really going to cost in those sizes, approaching 8 inches diameter???
What about the Correctors for something like my 330mm BK7 blanks that I was thinking into making Jones 330ASC
Looks like if it scales down Ok...then the Primary Margin mirror in BK7 would be around 250mm...doable in cost.
Is this an "All Spherical System" also?
At F1.5 if the corrector blanks do not kill the bank, I would really be interested in this design.
Nothing wrong with Ed's , but the speed is really interesting and wide field to boot...
Your one of the Kindest most giving people on this board and it is Very Much Appreciated.
You stimulate the old Knogen or the gray matter between the ears.