I'm gonna be working on portraits and I've been reading two interesting articles with good and believable recommendations, but there's conflicting report: for a blurry background one says that it's best to keep the ƒ-value as high as possible e.g. ƒ/5.6; the other says the ƒ-value should be as "small as possible" to avoid motion blur and a higher shutter speed e.g. ƒ/3. But as I can remember, the smaller the number, the aperture would open bigger and thus shortening the exposure. This will also produce a more blurry background. Am I correct? Something else: at what focal length do you recommend? I was thinking about 50-60mm for a rough guess (don't have my camera with me at the moment). Also, I will probably be using flash in a darkish room. I'll get bouncers (not the party ones), I think for a classic portrait would be light from slightly to the sight and a bit higher than the person's face. Any other thing I should make note of? Thanks!