Black Patch

[jgs001]

It was such a nice day today, and the sun was actually shining in a mostly clear blue sky, so I thought I'd have a look at the big spot region that release the CME. Only to find ,mMy Baader solar filter has developed a black patch, not very big, but it's a hole of some sort in one of the two layers, but big enough to be dangerous... so I'm not using it. I'd love to know how it happened, it's been packed in a box and was clean when it went in...

Anyone have any ideas ??

I did manage to have a look with my camera and lens (I made a solar filter out of a pair of UV filters and a disk of astrosolar film... A huge and impressive region (albeit rather tiny, even at 10x liveivew on the LCD display...)

[jimmyjamjoejoe]

Hmmmm could be some kind of mould? Doesn't necessarily mean it was dirty/damp, just an unlucky spore or something maybe...

[Peter Drew]

Just stick a bit of opaque material over the patch/hole, you won't notice it.