Re: [ATM] phase contrast testing with a film filter line,was: Zernike (or Lyot) phase contrast tests

["Nils Olof Carlin" <nilsolof.carlin@telia.com>]

Guy Brandenburg


> Thanks. Sounds like Wolfgang totally disagrees with
> the other method. Now I'm really confused.

perhaps I should avoid adding to this confusion - but as I have understood,
Wolfgang uses the film to make the "phase plate" that Herbert Highstone
makes from sooted glass - HH uses the film to record his image instead.

In the Lecleires' "A manual for telescope makers" is a suggestion to try 
something that may be called a "Poor Man's Lyot", using a very bright 
light source, but advancing the KE to cut out most of the light, thus 
highlighting small-scale defects. Might be worth some experimenting....

Nils Olof


> > Here you will find my report and how to produce that
> > filter line.
> >
> http://home.t-online.de/home/wolfgang.rohr/phaskont.htm
> > The edge of that line is unsharp and allows a
> > special Foucault effect.
> > Here you will find another discription:
> >
> http://www.astrosurf.com/tests/test460/test460.htm#haut
> >
> > I use a 0.1 mm small filter line on a negativ film
> > which reduces the direct light
> > by the factor 200 and compares it with the indirect
> > spreading light. My light
> > source is a light slit with 0.01 mm distance and 0.5
> > mm hight.
> >
> > Wolfgang Rohr, Germany,  info@optikpruefung.de
> > _______________________________________________
> > ATM mailing list http://www.atmlist.net/
> >
>
>
> =====
> Guy  Brandenburg
> Washington, DC
> My home page:
> http://home.earthlink.net/~gfbranden/GFB_Home_Page.html
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


_______________________________________________
ATM mailing list http://www.atmlist.net/