Bill and Margaret
I think that the filter you are refering to is a didymium filter. If you cannot find one let me know and I probably have one in my lab. This filter accentuates pink to red hues and is very useful for hematoxylin and eosin in which the eosin is a bit faded.
If you prepare a digital image however it is possible to made dramatic changes such as color balance, brightness, edge separation etc. with several computer programs such as Adobe, Photoshop etc.
Although I am not a photographer, I seem to recall as noted below that for B and W film to supress any specific color you should use a filter of the same color. To accentuate a color use the opposite color 
e.g. to accentuate red use green 
to accentuate blue use orange 
and vice versa. 
Barry

	-----Original Message----- 
	From: histonet-bounces@lists.utsouthwestern.edu on behalf of Bill Sinai 
	Sent: Sun 7/25/2004 4:58 PM 
	To: 'Margaret Blount'; histonet (E-mail) 
	Cc: 
	Subject: RE: [Histonet] Microscope filters
	
	


	Margaret,
	
	Many years ago when I did all the photography for the department I used a
	filter "dydim or diadim" which gave much better results to colour
	photography using a T64 Kodak Professional colour film.  I am not sure if it
	will be the same for digital cameras, I purchased this filter from a
	microscope supplier, however I believe that any photographic store should
	have them.
	
	Bill Sinai
	Laboratory Manager
	Tissue Pathology, ICPMR
	Westmead NSW 2145
	Australia
	Ph 02 9845 7774
	
	
	-----Original Message-----
	From: histonet-bounces@lists.utsouthwestern.edu
	[mailto:histonet-bounces@lists.utsouthwestern.edu]On Behalf Of Margaret
	Blount
	Sent: Friday, 23 July 2004 5:59 PM
	To: 'Geoff McAuliffe'; Margaret Blount
	Cc: Histonet (E-mail)
	Subject: RE: [Histonet] Microscope filters
	
	
	Dear Geoff,
	
	Thanks, that is a great help. My colleague isn't actually using film as he
	has a digital camera, but I will do a s you suggest and contact the
	microscope manufacturers for trial samples. I can easily pop into Jessops
	any time.
	
	Thanks again
	
	Margaret
	
	-----Original Message-----
	From: Geoff McAuliffe [mailto:mcauliff@umdnj.edu]
	Sent: Thursday, July 22, 2004 7:44 PM
	To: Margaret Blount
	Cc: Histonet (E-mail)
	Subject: Re: [Histonet] Microscope filters
	
	
	Hi Margaret:
	
	    Assuming your colleague is using black and white negative film, a
	blue filter will pass more blue light to the film and give more density
	in the negative. When printed, that will translate to the blue subject
	being lighter on the print. That said, there are lots of blue filters
	used in photography and some trial and error may be needed. There are
	lots of different "daylight filters", depending on the light source and
	the amount of correction needed, an 80A filter might be blue enough for
	your application. The standard blue filter for making RGB separations is
	a #47 and it is a fairly dense blue-purple color. A #46 is very similar.
	Such filters are sold in photo stores that cater to professional
	photographers (Jessop's in the UK is one) but you might be able to find
	something in the AudioVisual dept at your institution or perhaps the
	manufacturer of your microscope might loan you several for a trial, you
	could then purchase the one that fits your needs.
	
	Geoff
	
	Margaret Blount wrote:
	
	>Hi all,
	>
	>I have a chinese colleague who requires a blue filter to suppress staining
	>for Nissl substance (violet) in brightfield transmitted light microscopy -
	>does anyone know what filter this is and a supplier of such a filter. So
	far
	>I have only identified a Daylight filter, but I am not sure if this would
	do
	>the trick or not. If anyone knows anything about this I would be very
	>grateful as would my colleague.
	>
	>Thanks in anticipation.
	>
	>Margaret
	>
	>Margaret Blount
	>Chief Technician
	>Clinical Biochemistry
	>University of Cambridge
	>Addenbrooke's Hospital
	>Hills Road
	>Cambridge
	>CB2 2QR
	>
	>
	>_______________________________________________
	>Histonet mailing list
	>Histonet@lists.utsouthwestern.edu
	>http://lists.utsouthwestern.edu/mailman/listinfo/histonet
	>
	>
	>
	
	--
	--
	**********************************************
	Geoff McAuliffe, Ph.D.
	Neuroscience and Cell Biology
	Robert Wood Johnson Medical School
	675 Hoes Lane, Piscataway, NJ 08854
	voice: (732)-235-4583; fax: -4029
	mcauliff@umdnj.edu
	**********************************************
	
	
	
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