Re: ATM Homemade Ronchi Grating! It Works!

[Bob Hazel <machead@qadas.com>]

I too made some nice looking ronchi screens. But still have not
mastered how to use them. Anyone care to tell me what I might be doing
wrong?
  I have a tester based on Berrys, moving light source. The light is a
three volt mini mag bulb. I remove the metal cover that my knife edge is
taped to. Place the screen over the lightbulb which is housed in a
cavity in a piece of wood attached to the tester. I can see the light
reflecting back inside the tester eyepiece, but it seems that I can only
see lines when I am either way in front of ROC, or way behind it. I have
tried rotating the mirror slightly so the reflection is about 4 inches
to the side of the tester so that I can just use my eye to view the
image. Same result.
Is my light source too strong? When I am at ROC, the lines are gone and
all I see is bright reflected light from the entire mirror.

  Thanks

bob-Denver,CO

ps: I am also a little confused about the 100 lines per inch. Is it 100
lines of black, with equal space between them per inch, or is it
50 lines of black with 50 lines of space?