Carl,

Yes, you have to be very careful cleaning optics like this that have  
special coatings that affect their function. The only advice I have  
is this: A couple of times our lab has ordered some specialized  
dichroic mirrors and emission filters from Chroma and when they  
arrive in their box they come with a small orange slip of paper that  
talks about cleaning them. This slip says that if there a smudge of  
something that you really need to get remove that can't be taken off  
by a stream of air, just use a piece of lens paper and put a few  
drops of warm water on it. Then lightly drag this wet tissue across  
the optic's surface in one direction slowly. Repeat if necessary.

As I recall, this topic of cleaning filters has come up on the server  
before about a year ago or less and several people had recommended  
the First Contact polymer. Try searching the archives on this for  
more information.

(No commercial interest for Chroma or Photonic)

John Oreopoulos


On 7-Oct-09, at 1:42 PM, Carl Boswell wrote:

> Hi all,
> I have some emission filters with dust that will not blow off, and  
> one with an obvious fingerprint, all of which show up as blurry  
> smutz in the image. I appreciate the need for caution when cleaning  
> filters with soft coatings; e.g. no organic solvents, no touching,  
> etc.  But what about a simple soak in dilute soap and water,  
> followed by dH2O rinse?  Or, will a polymerizing cleaners, such as  
> Photonic's First Contact work?  Obviously there is a solvent in  
> this to keep the material liquid until applied.
>
> Thanks,
>
> c
>
> Carl A. Boswell, Ph.D.
> Molecular and Cellular Biology
> University of Arizona
> 520-954-7053
> FAX 520-621-3709