A while ago I received a request by a viewer who was anxious to see pictures of a specialist treat at the museum: an Austrian made Gatling gun, by Paget. I could not take a picture earlier, for without flash the gun was near invisible. Thanks to the 6400 ISO's in my D3 I managed. I realise this is a highly specialist gallery and that it has has nothing to do with photography as an art. But still I know some viewers will like it a lot. Some more information on such a gun I found at a page on Austro-Hungarian Rapid Repeating Gatling Gun.
Given the high ISO the pictures are, after some extra sharpening, reasonably sharp, but I still had to use a wide aperture, so not much depth of field or detail.