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12-23-2011, 10:18 AM   #1
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Join Date: Mar 2009
Location: OH, USA
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filter holder solution for 50mmx50mm dichroic filter

I have a question regarding an effort to do some fluorescence photography. Using dichroic filters and a blue led light source, I intend to photograph Green Fluorescent Protein (GFP). To the best of my knowledge and google's search abilities, the dichroic filters come in 50mmx50mm or 25mm diameter. The closest I come to a filter holder is Cokin A at 67mm. As I see it, the only option available is to create a secondary filter frame to build out the 50x50 to 67x67. Does anyone have any alternative suggestions on how this might be accomplished? Thoughts on creation of the secondary filter holder?
Some pertinent details:
Camera - K-5
Lens - A50, or DA21
GFP emission lamda (max) - 510nm
Emission dichroic filter - Edmunds Optics nt52-544
abstract describing effort I am trying to emulate - Botany 2010 - Abstract Search
other relevant efforts - GFP Stereoscope


12-24-2011, 02:20 AM   #2
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Join Date: Mar 2009
Location: Adelaide.
Posts: 8,795
interesting question, Lee do make Dichroic filters to custom sizes and specifications - they may be able to make a filter with the narrow bandpass you need. Lee Dichro filters can be placed in a custom sized metal frame that should suit the Standard Lee filter holder which is 100mm wide. I presume the dichro filter you are planning on using from Edmunds optics already comes in a frame? and secondly what is the thickness of the filter itself? may not be possible to securely fit the filter in the slots in the cokin holder ( it may be too thick to fit the holder)

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