The RAW image section for Opportunity has some images taken at sunset. Downsampled though

http://marsrovers.jpl.nasa.gov/gallery/all...unity_p020.html

They used the welder's glass filter when the sun was higher, but switched to L2 (infrared) when it was a few diameters from setting. I guess they knew it would be safe. Sounds a little hairy though pointing the camera into the sun. I wonder what kind of safeguards they have on that generally.