Re: Trying to image Cy7.5 -- AxioObserver.Z1 blocking IR?

Posted by Benjamin Smith on
URL: http://confocal-microscopy-list.275.s1.nabble.com/Trying-to-image-Cy7-5-AxioObserver-Z1-blocking-IR-tp7586976p7586980.html

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As others have pointed out, the strong 700 nm cutoff sounds very much like
a hot-mirror somewhere in the path, as that is a very common cut-off for
hot mirrors:
https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=6108
https://www.edmundoptics.com/optics/optical-mirrors/specialty-mirrors/hot-mirrors/#resources
https://www.chroma.com/products/parts/hot-mirror-26mm-50mm

The hot mirror should be close to the light entry port on the microscope.
Some microscopes allow the mirror to be flipped out with a lever, while on
others it has to be physically removed.  A Zeiss rep should know exactly
where it is in the path.

Good luck,
   Ben Smith


On Tue, Jul 11, 2017 at 7:30 PM, <[hidden email]> wrote:

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> Post images on http://www.imgur.com and include the link in your posting.
> *****
>
> Hi Michael,
> if you get the same readings before the filter cube (i.e. with the filter
> turret removed), then there might be an IR blocking (heat blocking) filter
> somewhere in the illumination part.
>
> According to this drawing
>
> http://www.zebrasc.com/Article.asp?pageclass=10201
>
> there is quite a number of elements in the light path. It could also be the
> AR coating of the lenses (e.g Thorlabs VIS coating reflects up to 5% per
> surface at 800nm), but the dramatic loss of intensity looks more like an
> intentional IR blocking. Zeiss reps will know more...
> Good luck!
>
> zdenek
> --
> Zdenek Svindrych, Ph.D.
> W.M. Keck Center for Cellular Imaging (PLSB 003)
> Department of Biology,University of Virginia
> 409 McCormick Rd, Charlottesville, VA-22904
> http://www.kcci.virginia.edu/
> [hidden email]
>
> ---------- Původní e-mail ----------
> Od: Cammer, Michael <[hidden email]>
> Komu: [hidden email]
> Datum: 11. 7. 2017 22:01:28
> Předmět: Trying to image Cy7.5 -- AxioObserver.Z1 blocking IR?
> "*****
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> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
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> *****
>
> A few weeks ago we asked about finding a light source at 780ish nm for
> exciting Cy7.5. As always, people on this listserv provided very helpful
> suggestions. We were able to get a pE-4000 system with multiple LEDs but
> are
> finding that the Zeiss AxioObserver.Z1 fluorescence illumination optics
> appear to be cutting wavelengths above 700 nm.
>
> We adjusted the LED powers such that 635, 660, 740, and 770 nm all have 52
> mW at the end of the liquid light guide. We removed the IR filter for the
> autofocus system that is in the objectives nosepiece. However, the light at
> 740 and 770 nm is blocked from arriving at the objective lenses.
>
> Does anyone know whether there is a filter somewhere else in the light path
> we could easily remove to pass these wavelengths or is this a limitation of
> the light train?
>
> (graphs of the power loss posted at http://microscopynotes.com/
> axioobserver/
> IR/ )
> Thank you!!
>
> =*===========================================================*=
> Michael Cammer, DART Microscopy Laboratory, NYU Langone Medical Center
> Cell: 914-309-3270 (this is for calling, not texting) Office: Skirball 2nd
> Floor main office, back right
> http://ocs.med.nyu.edu/microscopy & http://microscopynotes.com/
>
>
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--
Benjamin E. Smith, Ph. D.
Imaging Specialist, Vision Science
University of California, Berkeley
195 Life Sciences Addition
Berkeley, CA  94720-3200
Tel  (510) 642-9712
Fax (510) 643-6791
e-mail: [hidden email]
http://vision.berkeley.edu/?page_id=5635 <http://vision.berkeley.edu/>