NavList:

Peter, you suggested:
"In cases like this, where the smaller audience is all near one spot, I wonder if the projection system can be told to predistort its image so that the audience sees an accurate view.  The projection software should have a button that says "put geometric sweet spot here"."

I've tried talking to this projection system, but all it does is stare blankly back at me with a hundred unblinking eyes. :) A great many small planetarium projectors, including the one at Mystic Seaport, are still just boxes with lots of holes and a bright light at the center. No software at all!

But yes, for a digital system there's the potential to do that. Digital systems are much more flexible in most ways (lacking only dynamic range, which unfortunately is a big issue). The ability to re-center the projection wouldn't help for sextant observations, of course. Even a few inches change in sextant position under a thirty-foot dome will yield 15 minutes of arc change in altitude.

Frank Reed