Quote:
Originally Posted by sopticals
Hi Dave,
Nice improvement with the 16" Loftus mirror. Is this a float glass substrate, and if so what thickness? What is the f ratio?
For the refiguring, did you use Cerium oxide, or rouge? What pitch hardness? Full sized laps, or sub diameter?
Stephen.  |
Hi Steve.
The 16" primary and secondary were both Float or Plate (I don't know how to tell the difference). I don't recall actually running a tape on the primary edge but I think it was 1". Definitely not thicker. ROC was 2460mm so f/3.075 for the primary, conic was -.555. Final f/ratio for the scope was 6.4!! The owner uses it mainly for imaging with a coma corrector. I just refigured the existing optics, not design the system
The refiguring was done with thin cerium oxide with a 110mm soft lap. See pic. A small amount of polishing was initially done with a 6" lap, which just fit between the outer edge and the central hole but 95% with the smaller one.
Dave