[ptx] Hugin with enblend

[Ian Sydenham]

I've discovered a limitation when using the enblend option from hugin.
It appears that for windows users (at least windows 2000) the total
length of the full path and file name of all images to be enblended
must be less than about 2000 characters. This sounds like plenty, but
can be easily reached with multiple row 360 deg panoramas filed in a
deap directory structure.

regards,

Ian Sydenham