For those interested in HDRI then this book
has much information.
There is a throw away mention about lighting maps that I must do work on that may be yet another way of manipulating monochrome images...and if you want to learn how to do a HDR panorama there are step by step sections...
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Chris
60N
1W
http://www.paddle.shetland.co.uk
http://www.paddle.shetland.co.uk/my%20piccys/index.htm