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Hi all,

Up until recently, it was hard to improve on the dark-adapted human 
eye as a detector for live-time widefield LM images.

Other image sensors might be better able to integrate weak signals 
over time or to perform well over a limited field of view, but in 
real-time, the rotatable eyeball was really hard to beat. Until last 
year the closest challenger was the EM-CCD, but this had relatively 
few pixels, only moderate readout speed and no color.

It is my impression that the new scientific CMOS detectors (such as 
those recently offered by Hamamatsu and Andor, no connection) may 
soon overcome these limitations. While it is true that, so far, they 
do not provide color images, they do have a wide field of view as 
well as fast readout, very low read noise and quantum efficiency 
significantly higher than that of the human eye.

I see no reason why, in the future, they could not be coated with 
color filters to produce a single-chip color sensor. Although the 
color filters will reduce the QE to white light by a factor of 3 or 
4, it is also true that the cones which allow human eyes to sense 
color are far less sensitive than the monochrome rods. So I think 
that, as long as we can figure out how to handle the massive 
information flow associated with sorting and displaying 5Mpixel, 
3-color, at video rates, we will still come out ahead.

Such image sensors may eventually replace the oculars and prism heads 
now common on scientific microscopes. Just compare the cost of these 
optics with that of a potentially mass-produced chip. Not only this, 
but such a system greatly facilitates keeping the specimen in the 
dark while the operator works in ambient light.

Indeed, we already see several manufactures (such as AMG, Mill Creek 
Washington. No connection) offering fluorescence microscopes in which 
all imaging is carried out via CCD sensors and LCD displays.

Until we come up with a "jack" to send such images directly into the 
optical centers of the brain (Heaven Forbid!), this may be the best 
we can do.

Cheers,

Jim P.

NOTE: I have no connection with Hamamatsu, AMG or Andor except that, 
like virtually all other microscope manufacturer, they have in the 
past provided instruments for use by students use at the UBC 
Live-Cell Course. I mention these companies only as examples that I 
happen to know about but I do so in the awareness that many other 
companies will soon be applying these and other sCMOS sensors in much 
the same way.
***************************************************************************
Prof. James B. Pawley,               		            Ph. 
608-238-3953              	           
21. N. Prospect Ave. Madison, WI 53726 USA 
[log in to unmask]
3D Microscopy of Living Cells Course, June 11-23, 2011, UBC, Vancouver Canada
Info: http://www.3dcourse.ubc.ca/	    Applications due by March 15, 2011
	       "If it ain't diffraction, it must be statistics." Anon.

>*****
>To join, leave or search the confocal microscopy listserv, go to:
>http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>*****
>
>Good afternoon,
>
>the straight forward way, if an additional camera port is available on the
>microscope, might be to mount a CCD camera and between the microscope and
>the CCD camera a C-mount adapter including a 0.32x or 0.5x scaler. The
>disadvantage is that the image produced by the camera will show "black
>corners" around the image of the FOV since the entire FOV is projected
>onto the CCD chip, which is rectangular, while the FOV is cicular in
>shape.
>
>If you canNOT proceed this way:
>You might try what just is an idea and I do not know whether this would work:
>
>The eyepiece, as many of the group members know, is used as a
>magnification glass to observe the real intermediate image, which, in
>most, possibly all, standards is located 10mm inside the tube which holds
>the eyepiece(s), distance measured from the edge to which the eyepiece is
>set.
>
>If your preps produce images with sufficiently large contrasts (otherwise
>use DIC or PC or another contrast method):
>If you would place (a) circular screen(s) made from a whitish,
>structureless material or possibly frozen glass into the tube(s) holding
>the eyepiece(s) so that the screens are positioned 10mm inside the
>tube(s), you would be able to view the real intermediate on these small
>screens. Of course, the image is much too small for eye observation, but
>you might place a digital photoapparatus in "near view mode" so that it
>will image this real intermediate image. I've just tried with my Olympus
>my 810, and it easily images the 25mm which is, as far as I know, the
>largest diameter of the FOV in the plane of the real intermediate image.
>
>
>Best wishes,
>
>Johannes
>
>
>>  *****
>>  To join, leave or search the confocal microscopy listserv, go to:
>>  http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>  *****
>>
>>  Folks, I am about to install an advanced imaging system (sweptfield
>>  confocal and widefield imaging combo) in a biosafety level 3 facility.  To
>>  work in the facility one has to suit up and wear a rigid face mask, as the
>>  cells/pathogens will be on the scope and may be open to the environment.
>>  This means that the eyepieces of the scope are essentially useless.  I
>>  wonder if any other listers have dealt with this problem and what their
>>  solution was? Obviously the widefield camera will help a lot, but it
>>  doesnt allow survey of the full field of view, as we are doing mostly
>>  flourescence a video camera isnt much use.... back in the day, there were
>>  some screen solutions....
>>  Looking for creative ideas
>>  S.
>>
>>  Simon C. Watkins Ph.D, FRC Path
>>  Professor and Vice Chair Cell Biology and Physiology
>>  Professor Immunology Director Center for Biologic Imaging
>>  BSTS 225
>>  University of Pittsburgh
>>  3500 Terrace St
>>  Pittsburgh PA 15261
>>  412-352-2277
>>  www.cbi.pitt.edu<http://www.cbi.pitt.edu>
>>
>
>
>--
>P. Johannes Helm
>
>Voice:	(+47) 228 51159 (office)
>Fax:	(+47) 228 51499 (office)


-- 
***************************************************************************
Prof. James B. Pawley,               		            Ph. 
608-238-3953              	           
21. N. Prospect Ave. Madison, WI 53726 USA 
[log in to unmask]
3D Microscopy of Living Cells Course, June 11-23, 2011, UBC, Vancouver Canada
Info: http://www.3dcourse.ubc.ca/	    Applications due by March 15, 2011
	       "If it ain't diffraction, it must be statistics." Anon.