February seems to be an important month for me, relating to Hasselblad. I purchased my first Hasselblad in February, 1972 (a new 500CM with 80/2.8 chrome lens and A12 back).
So this month (February 2012) marks the 40th anniversary of my continued relationship with the Swedish company. But it also marks the anniversary of my CFV woes, which are listed here -
February, 2008 - I went digital, purchasing an original CFV for $9000 (Hasselblad had a $1000 incentive at the time).
February, 2010 - My CFV developed some strange fungus underneath the IR filter. Final cost of repair, including sending it to Denmark - Over $500 plus 6 weeks timeframe.
February, 2012 - I took my camera out yesterday (first time this winter), and noted once again some strange artifacts showing up on my images. As my heart sank to my stomach, I shot an image of the overcast sky. Sure enough, I have more crud on my IR filter again. A final scrutiny of the IR filter with a Rodenstock loupe verifies. So it seems that another trip to Denmark, and another $500 in eminent.
I'm wondering if not using the back for a few months during the winter has anything to do with it? FWIW - my camera rested in its backpack case, with DB and lens mounted. I don't know how this stuff creeps in!!
Below I've included the shot made of an overcast sky, clearly showing all the unwelcome invaders. Hopefully the jpeg enlarges enough to see them. I'm waiting for Hasselblad USA's response before sending it to them.
Note - the black spots you see are a very light colored cyan on the actual IR filter, while the filament pieces are white, almost crystalline.