Thanks Mike, I used to use the 20cm for a dedicated supernovae search designed for galaxies of mag 11.5 and with possible supernova visible down to about the theoreticle magnitude of mag14.5, and on quite a few times observed supernovae (post discovery) of this magnitude.
When I got the 40cm and the ARGO NAVIS I was able to go about a magnitude fainter and regulaly observe stars down to 15mag or fainter, Robert Evans I aint thats why it takes me so long, I have to scan nearly every galaxy diligently before going on to the next one, there area few galaxies that I can remember the star fields so they are perused more quickly.
I use the Thompson Supernovae Search Charts, also the CCD Atlas by Wassillef and numerous images downloaded from the internet, all told I have about 9,000 galaxy images to check with
