I've been doing a few portraits with my LF camera, using a 300mm barrel lens wit h polaroid (52) as well as film. I'm discovering now how much I miss the luxury of short shutter speeds I got with shuttered lenses! Since I'm using a barrel le ns I have to get exposures down to 1-2 seconds, which makes capturing spontaneou s expressions practically impossible! What is the best method of creating portra its, given this limitation? It's a completely different kind of experience for a sitter to be aware and be able to move (though he/she shouldn't) and think DURI NG an exposure. Much more pressure... I know, for instance Avedon coaches his su bjects it a way to produce the objective/constructed reality/fiction expression that he wants to create, but I haven't found much in the way of reading or guida nce on how to go about this... My normal method is to simply build rapport with a sitter, and capture (with a fast shutter speed) a brief expression that embodi es something about what I think about the sitter, but that becomes much more dif ficult when I have to ask the subject to sit still for seconds at a time. How sh ould I approach this?