Subjects

Optical
Shop

Polishing
Bowl

Edging
Machine

Null
Tester

Tube
Fittings

Worm
Drives

Optical
Workshop Equipment

Spindle
Nose & Adaptors

Slip
Ring Seting Circle

Mirror
Cell

Diagonals

Odds and Ends 
RONCHI GRID.
Multiplying this distance "K"in inches by the number of wires per inch
on the grating gives the magnifying ratio for that particular zone ,
whose radius is ½ K. Dividing the racius of curvature of the mirror
by this ratio gives the distance "d" from the grating to focus of this
zone. For a spherical mirror ail zones have the same focus, so "d" is
constant for all zones and the magnifying ratio B/d is constant, so
the distance apart of the shadow bands is constant for all zones and
they are thus parallel straight lines.
Prepare the following table.
