frankly speaking, I know very little about consumer DCs. from the specifications of the two cameras, I think that sony dsc T100 is more stylish, canon sd850 is more practical. the little toys from canon sometimes has pretty good lenses, especially, comparing with the sony's. although sony says the their lenses made by Zeiss, they often have one piece of zeiss glass in the lens generally. I have a small canon binocular, it is very bright and beats the Zeiss binocular I have, but the cost is only 1/8 of Zeiss.

did you ask about Nikon Coolpix S10 before?

F.Y.I. G.D.