Re: ATM ronchi mayday...

["'rjf@skyhackers.org'" <rjf@skyhackers.org>]

On Wed, Oct 11, 2000 at 10:50:04AM -0400, Sidor . Kurt wrote:
>       "I counted the lines on my grating
> - -- 5 dark lines in .1" (so 10 counting the clear ones) for 100 per
> inch (the grating is 2" square.
> 
> Rochi rulings are rated in lines per inch.  A "line" set is one
> clear AND one opaque.  So in 0.1" you got 5 dark lines so in 1.0"
> you will get 50 dark lines.  Your ruling is a 50 line per inch
> ruling.  That should "straighten" things out. :) !

Doh! This is it! I thought it was number of total lines (dark and
clear). When I enter 50 into Ronchi for Windows, I do indeed get
something way in the right ballpark for what I am seeing.

So the question is, is it realistic for me to use a 50 lines/inch
grating for this? Or should I set about making a 100 line/inch one?

Thanks Kurt (and others!)
rjf&