I'm relatively new to photography, so I had a question regarding this lens.. I just bought it for my Nikon D50.. to take some good portrait pictures. I was testing it out all day today, and the pictures are beautiful. I love that out-of-focus blur it gives at f/1.8. Now, the puzzling part is.. are the pictures supposed to be soft at 1.8? Or sharp? I took some pictures of my wife's cat (in the garage.. ISO 400 and shutter speed of 160) .. and the pix looked terrible.. very soft. Almost as if, I didn't focus right. When I used my sb-600 flash, and moved the shutter speed to 500.. the pictures were much better. All this, at f/1.8. So are the pictures always soft at f/1.8? I mean, the whole point of using a lens like this in low light situations is the f/1.8 thing.. but if the image comes out soft.. I'll have to go to f/3.0 and above.. which kinda beats the whole purpose. Sheesh I'm confused! Please help.. thanks!