Also, Barney, this line is the one that precipitated making the `nobjects_only` option, since this line is rather slow.  Like of order 1 second each time.  So on the first time through the config processing, when all I need is the number of objects in the catalog (to set up the random number seeds), there was a lot of wasted calculation being done here.  

So the `nobjects_only` option skips this, but can you think of anything that might be done to speed this line up?  I played around with the FITS_rec class trying to figure something out, and nothing was very forthcoming.  This line is kind of a brute-force conversion from the field storage to a numpy array that turns out to be not super efficient.