Re: DIY phase contrast annulus

Posted by Guy Cox-2 on
URL: http://confocal-microscopy-list.275.s1.nabble.com/DIY-phase-contrast-annulus-tp7584253p7584258.html

This all seems really over the top.  I made one simply by drawing it with Indian ink on optical glass.  I cleaned the pattern off an old one which didn't match any objective I had, and used a Rotring pen to draw the inner and outer circles with a compass, then inked in around them.  Of course it took care, but microscopists are surely used to delicate work.  Cost - zilch.  This was 35 years ago -  I still have it and anyone is  welcome to visit and try it.  

                                       Guy

Guy Cox, Honorary Associate Professor
School of Medical Sciences

Australian Centre for Microscopy and Microanalysis,
Madsen, F09, University of Sydney, NSW 2006

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of JOEL B. SHEFFIELD
Sent: Tuesday, 29 September 2015 11:29 AM
To: [hidden email]
Subject: Re: DIY phase contrast annulus

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We have made Hoffman condensers using aluminum foil.  I see no reason that you couldn't do something similar, using the mask that you have generated, to carefully cut out the ring in a sheet of aluminum that is already tacked down to a piece of glass.

Joel



Joel B. Sheffield, Ph.D
Department of Biology
Temple University
Philadelphia, PA 19122
Voice: 215 204 8839
e-mail: [hidden email]
URL:  *http://tinyurl.com/khbouft <http://tinyurl.com/khbouft>*

On Mon, Sep 28, 2015 at 8:56 PM, Rusty Nicovich <[hidden email]>
wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> Post images on http://www.imgur.com and include the link in your posting.
> *****
>
> Ben,
>
> You could use chemical etching to reproduce your printed annulus on a
> piece of copper or brass.  Electronics DIYers make PC boards by laser
> printing a pattern onto glossy paper, using an iron to transfer the
> toner to a piece of copper-clad PC board, and the ferric chloride to etch away the copper.
> Same principle will work on brass.  Takes some trial and error and a
> few nasty chemicals, but is a great way to get high-resolution parts
> out of sheet metal.
>
> Another option is to have the annulus laser-cut.  Shouldn't cost more
> than
> $20 for something annulus-sized.  Usually you need to supply the
> operator with an Adobe Illustrator or other vector drawing format but
> you already have the drawing.  The cutter here is run by the
> architecture design school and their cutter has a resolution of ~300
> microns.  Should be able to get stainless steel or even powder-coated
> aluminum cut without too much hassle.  This would be my preference
> since it requires less OH&S work on my part.
>
> Rusty
>
> On Tue, Sep 29, 2015 at 9:53 AM, Smith, Benjamin E.
> <[hidden email]
> >
> wrote:
>
> > *****
> > To join, leave or search the confocal microscopy listserv, go to:
> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> > Post images on http://www.imgur.com and include the link in your
> posting.
> > *****
> >
> > Hey Microscopists,
> >     A lab here has a nice phase objective but no annulus, so I
> > decided to see if I could make one for them.  I measured the phase
> > plate diameter at the focal plane, and printed out an annulus that lined-up perfectly.
> > However, too much light gets through the ink to be of much use, so I
> > was wondering if anyone had experience with an easy way to make a
> > fully
> opaque
> > annulus.
> >
> > Cheers,
> >    Ben Smith
> >
> > Benjamin E. Smith, Ph.D.
> > Samuel Roberts Noble Microscopy Laboratory Research Scientist,
> > Confocal Facility Manager University of Oklahoma Norman, OK 73019
> > E-mail: [hidden email]
> > Voice   405-325-4391
> > FAX  [phone]
> > http://www.microscopy.ou.edu/
>