50d raw
 

The Canon 50D has 3 RAW settings 15.1mp 7.1mp & 3.8mp.
If printing at A4 which is the best setting to use ?
In what circumstances would you use 3.8mp ? Other than to save space on your memory card ?
Does the 15.1mp setting have any additional use other than allowing you to make bigger prints ?

It would only be to save space on a card.. I guess if you had a slow writing card, using a small size file would allow maximum FPS.

For A4 you will get away with 7.1 mp. However, if you one day take the stunning photo of your life that will be worth millions, you really need it at as high a MP as possible, getti images for example demand a high MP level..

Taking at a higher MP, as well as bigger prints gives you the chance to crop your image keeping some level of sharpness..

to be honest with the price of compact flash cards nowadays card space shouldn't be an isssue
the only advantage would be in continuous shooting ( more frame per burst ) but thats where it ends really
i can see no other advantage of using the smaller raw settings in fact over the time i have owned a 50d ( from launch ) i have never used anything but 15.1mp raw i don't see a reason to use the others

when i read this post it reminded me they have other raw settings i'd completely forgot about them :)