Variable fluid media radiation filter

A variable fluid media radiation filter apparatus comprising:

• a pair of opposing, spaced, radiation transmissive members, said members having opposing edge portions, and first and second opposing ends, said first end being elevated with respect to said second end;
• sealing means sealing said opposing edge portions, said opposing members and said sealing means defining a cavity;
• first and second bellows means being compressible and expandable so as to have variable volumes;
• fluid transmission means at each of said first and second opposite ends of said members interconnecting said first and second bellows means with said first and second opposite ends, respectively, said fluid transmission means rendering said first and second bellows in communication with said cavity, said first and second bellows, said transmission means and said cavity defining a closed volume;
• a plurality of immiscible fluids of different specific gravities and radiation transmission characteristics, said fluids filling said closed volume, the fluids within said cavity and said radiation transmissive members forming a radiation filter;
• and
• bellows actuating means for selectively compressing one of said first and second bellows means and expanding the other of said bellows means to force a portion of said fluids into and out of said cavity, to vary the filtering effect of said radiation filter on radiation incident on said filter.