Dear David,

Nikon have three types of water immersion lenses. As you correctly point out
some are designed for coverslip correction, others are dipping type lenses
with no correction collar. However they do have one other lens that is a
hybrid called a multi-immersion lens (CFI Plan Fluor 20X MI 0.75NA). The lab
you are in may have one of these. This has a correction collar and
anti-spill "moat" like the lenses for use with coverslips. However this lens
may be used with Oil, Glycerin, or water, with or without coverslip (ie. six
different conditions [possibly only five!]).

The markings on the correction collar indicate the various settings; the
equals sign ( == ) indicates with coverslip, the not equals sign ( =/= )
indicates no coverslip. I presume these lenses are designed for 170um thick
coverslips, but if you move the collar slightly back from the == symbol you
should be able to get a rough correction for thinner coverslips.

No commercial affiliation with Nikon.

Regards
Stephen H. Cody,
Colon Molecular and Cell Biology Laboratory,
Ludwig Institute for Cancer Research,
Post Office Royal Melbourne Hospital,
Parkville, Victoria 3050, Australia.

Tel: +61 3 9341 3155 (BH)   +61 3 9341 3158 (@work AH)
Fax: +61 3 9341 3104
email: [log in to unmask]
www.ludwig.edu.au/colonmolecular/cody.html


> ----------
> From:         David Knecht[SMTP:[log in to unmask]]
> Reply To:     Confocal Microscopy List
> Sent:         Monday, 10 September 2001 20:39
> To:   [log in to unmask]
> Subject:      water lenses
>
> I am working in a lab temporarily which has a Biorad confocal set up
> on an upright Nikon Eclipse.  They use the Nikon confocal water
> immersion lens as a dipping lens on this system.  My impression was
> that these lenses were designed to correct index mismatching, but
> that they were intended to go through a coverslip, since there is a
> correction collar for coverslip thicknesses.  Can someone comment on
> whether one would expect any optical abberations from using it by
> dipping without a coverslip?  Thanks- Dave
> --
>
> ************************************************************
> Dr. David Knecht
> Department of Molecular and Cell Biology
> University of Connecticut
> 75 N. Eagleville Rd.   U-125
> Storrs, CT 06269-3125
> [log in to unmask]
> 860-486-2200      860-486-4331 (fax)
> home page: http://www.sp.uconn.edu/~mcbstaff/knecht/knecht.html
> ************************************************************
>