I just recently acquired a mint condition 5D from the mid 2000s with very little use, looks like new, but has been sitting for 15 years. It did have a small amount of dust in the focusing screen prism that I wanted to remove since it was visible through the viewfinder. I made the mistake of trying to whisk the dust particles away using one of those small inexpensive (cheap) lens brushes with the blower bulb. When I did this the brush shed one of its hairs (about the size of long eyelash onto my focusing screen. It was very difficult to remove the hair but I believe it finally came off, hopefully OUT of the camera. My questions is what is the best way to clean a Canon EOS focusing screen and mirror? Is there a dry and wet method? I am not touching the sensor yet. I did order one of the large Giotto's blower bulbs as this is what I should have used today but did not have.
I assume sensor cleaning fluids are alcohol based and some plastics don't get along with alcohol, they melt. If there is such a thing as a "wet clean" for focusing screens the fluid would need to be very gentle and the applicator would have to be feather soft.
I don't understand why someone could not just remove their dirty focusing screen from the camera body, rinse it under look warm water, and pat dry with a micro-fiber cloth. On a 5D the screen looks to be easily removable with one clip.
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