Hi Karl, > just a point regarding the histogram gaps - the histogram tool is a small > graphical representation in Photoshop that is only 128 pixels wide on the > screen and while 8 bit images will show gaps in theat graph more readily > than 16 bit images, a larger graph will show that many 16 bit images which > appear to have no gaps in the photoshop histogram to actually DO have gaps, > they're just not represented on such a small graph. You're right with this. Even 16bit/channel images can have histogram gaps, although, as you say, is much more easier to get it using 8bit/channel images. If you don't have it already, there's a freeware plugin for Photoshop wich shows a big histogram, wich will allow you to see the histogram representation more accurately: http://www.reindeergraphics.com/free.shtml Regards