I was assuming that a microscope which was basic enough not to have a field iris was unlikely to have a Bertrand lens!

                                     Guy

Optical Imaging Techniques in Cell Biology
by Guy Cox    CRC Press / Taylor & Francis
     http://www.guycox.com/optical.htm
______________________________________________
Associate Professor Guy Cox, MA, DPhil(Oxon) 
Electron Microscope Unit, Madsen Building F09, 
University of Sydney, NSW 2006 

Phone +61 2 9351 3176     Fax +61 2 9351 7682
             Mobile 0413 281 861
______________________________________________
      http://www.guycox.net
 


-----Original Message-----
From: Confocal Microscopy List [mailto:[log in to unmask]] On Behalf Of MChua
Sent: Friday, 22 January 2010 12:51 PM
To: [log in to unmask]
Subject: Re: Kohler equivalent

And of course an elegant way of focussing the condensor aperture is to  
use a Bertrand lens, which tends to be included with many good quality  
scope setups.   Removing the eye piece as Guy describes is a cheep  
alternative to a Bertrand lens!

Michael
919-943-3268
[log in to unmask]
http://microscopy.unc.edu
Michael Hooker Microscopy Facility



On Jan 21, 2010, at 7:54 PM, Guy Cox <[log in to unmask]> wrote:

> The other responses were a bit gloomy – in fact it’s quite  
> easy.   Look down the tube (without an eyepiece) and adjust the cond 
> enser height until the condenser iris does what it’s supposed to do. 
>    That is, when  you open it fully the whole of the bfp is illumina 
> ted and as you close it the illuminated area decreases smoothly, wit 
> h a sharp edge, down to a little spot.  (You could use a phase teles 
> cope for this but it can be a bit fiddly knowing where to focus it.) 
>   You will find that if the condenser isn’t focussed  correctly you  
> will not be able to fill the bfp, and you will see strange effects s 
> uch a dark patch in the middle as you close it.   It’s really easier 
>  to do than to explain!
>
>
>
>     
>     
>     
>     
>     
>     
>     
>     
>     
>                                                                       
> Guy
>
>
>
> Optical Imaging Techniques in Cell Biology
>
> by Guy Cox    CRC Press / Taylor & Francis
>
>      http://www.guycox.com/optical.htm
>
> ______________________________________________
>
> Associate Professor Guy Cox, MA, DPhil(Oxon)
>
> Electron Microscope Unit, Madsen Building F09,
>
> University of Sydney, NSW 2006
>
>
>
> Phone +61 2 9351 3176     Fax +61 2 9351 7682
>
>              Mobile 0413 281 861
>
> ______________________________________________
>
>       http://www.guycox.net
>
>
>
>
>
> From: Confocal Microscopy List  
> [mailto:[log in to unmask]] On Behalf Of Vasseur Monique
> Sent: Friday, 22 January 2010 4:41 AM
> To: [log in to unmask]
> Subject: Kohler equivalent
>
>
>
> Hi everyone,
>
>
>
> To do Kohler illumination alignment, we need a field diaphragm and a  
> condenser on the microscope.  What about the ones that have only a  
> condenser with adjustable aperture, and no field diaphragm;  is  
> there a kind of standard method to properly adjust the height of the  
> condenser, for upright and inverted microscopes?
>
>
>
> Monique Vasseur
>
> Microscopie et imagerie
>
> Département de biochimie
>
> Université de Montréal
>
> C.P. 6128, succursale Centre-ville
>
> Montréal QC    H3C 3J7   Canada
>
> tél. (514) 343-6111 poste 5148
>
> No virus found in this incoming message.
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> 01/21/10 06:18:00

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