Dark-room timer

Although we would not denigrate the many photographic development and printing services (wh ich vary fram poar to fairly good), it is a fact that many serious amateur photographers would not dream of sending their carefully taken and exposed films to one of these bureaux. Many others are hesitant to do so. This article is aimed at all these photographers. It describes a darkroom timer that is calibrated in f numbers. This kind of calibration makes the timer much easier to use than the traditional ones that have a linear scale.