Yes. That is exactly what I mean. And I know I can't do it. So what I need to know is who can do it? Maybe the best thing is to send it to Hasslblad, but maybe someone on the list has a special recommendation. Sherman On Jan 13, 2011, at 12:34 AM, Richard Man wrote: You mean between the IR cutoff filter and the actual sensor itself? If so, definitely sounds like a job for a professional with cleanroom etc. Don't do it yourself!! On Wed, Jan 12, 2011 at 4:50 PM, Sherman Bloom <shermanbloom@xxxxxx> wrote: My CFV-16 back needs a cleaning. Seems like some particulate matter is behind the bypass filter. Any recommendations for someone special I should use for this? If any of you happen to be in Salt Lake City on Jan 22, you might drop into the municipal library (an architectural achievement worth coming to see in its own right) to see an exhibit of mine that will be opening that day, at 3:00pm. Sherman Bloom -- // richard <http://www.imagecraft.com/> // icc blog: <http://imagecraft.com/blog/> // photo blog: <http://www.5pmlight.com> [ For technical support on ImageCraft products, please include all previous replies in your msgs. ]