Digital BW, The Print

The more I read about it the less I understand it. I'm using a Canon
Rebel. For highest image quality it produces a "RAW" image. The files
themselves are of *.CRW type. I run them through a Canon supplied
program which converts the RAW files to *.tif files. When I open the
*.tif files I actually get two images, one high resolution, one low
resolution. I have no use for the latter but have to take the time to
open the parent file and then delete the unwanted file.

Maybe someonne can explain to me, in simple terms, what this is all
about and how, if possible, I can rid the master files of the unwanted
low resolution .tif file.

Thank you very much.