In Sally Mann's beatiful Intimate Family several of the pictures are sharp in the middle but feature an abrupt decrease in sharpness towards the edges and corners. It's not subtle (but strikingly effective). <p> She uses an 8x10 view camera, but how is the sharp/soft effect above achieved? (1) Is it during the taking stage or in the darkroom? (2) Is it (as I suspect) an effect of using lenses that are made for smaller formats than 8x10? (3) If none of (1) or (2), what? Coke-bottles? <p> Thank you for any answer from you knowledgeable large- format shooters. Note, this is a technical question, not a question on how Sally Mann is able to turn out the pictures as she does (which would require a strong mother-child bond anyway, in addition to skill).