Donna, you casually mention 'the lab.' My concern is that unless you are dealing with a top-notch black and white lab [pretty expensive & rare] chances are very good that you won't get optimum development of your black and white film, no matter what you tell them.(posted 8605 days ago)The info in the above posts is very good, but unless you or the lab develop the film in a very controlled environment, it won't make much difference.
chris