PHOTOGRAPHY -40

 PHOTOGRAPHY -40

WHAT GOES ON IN A DARK ROOM

A dark room intended for handling photofilms and photo paperand  is maitained free from seepage of light , while it provides for in flow of fresh air and permits ‘escape of chemical fumes and exhaled breath of worker[s] inside. Dark room meant for colour printing and colour film processing is an absolute light-free zone until the lights inside are switched on. Colour emulsions are too sensitive as to suffer damage from any trace of light and photoprints that had ‘contacted’ unintended light sneaks show off red tint of blood stain along the edges and is bound to give unwanted colour casts viewed as offensive intrusion. The concept is, until processed to finality, films/ paper are held through dark ambience –as to possess only dye records that contribute to the image. So, processing of films required to confine the film to a dark container while the technician stays in convenient states of light and air. Such small chambers’ of film process confines were named ‘tanks’, that permitted flow of liquids into /out of the container through ‘light proof’ passages designed to serve as conduits for liquid movement. So, each step of the process requires contact between the film and the relavant chemicals for a specified length of time at defined temperature[s]. This ‘tank design’ helps monitoring the parameters like liquid volume, temperature and time of interaction without having to grope in the dark. Around 30-40 seconds before the ‘end’ time the liquid is drained into a container and water or chemical solution let in,  freezes the action of the previous batch of chemicals and is named ‘stop bath’. The next batch of chemicals carry the reaction forward to complete the steps in “image formation”.   ‘Image formation’ in traditional film photography can be divided into 2 forms of action –a] Physical and b] Chemical. The physical step is interaction between a sensitive surface[ film or paper] and controlled beam of light permitted to act on the surface. The play of “controlled light beam’ is mediated by camera [picture taking]  and again by ‘printing light or Enlarger’ in the dark room.  The physical act affects the light sensitive  film or paper; such ‘light-affected’ areas are chemically acted upon to form the image. That done on film is named ‘film processing’ and  the one done on paper is named ‘printing’.  The image on the film is ‘negative image’ and that transferred on to a paper or film is  POSITIVE IMAGE or Print [paper] or Transparency [film]. At this stage, a number of questions may crop up as to the length of ‘processing time’. Process schedules for films B&W / COLOUR are suggested by film manufactures and at times by manufacturers of chemical substances specifying optimum ‘handling time’ and work temperature . Accordingly adequate volume of water at defined temperature is kept ready before the start of a session. It heps to run the process in the time stipulated. Until near the final step is completed the film is kept in the light-proof box. After the steps are duly completed . the film is unwound from the spiral track and left to dry on a clothline –say in a bath room. Bath rooms being basically wet , all dusts settle down leaving the air free of suspended dust. The film left suspended in a bathroom has very low chances of picking up aerial dust and is a wee bit slow to dry; yet , ultimately reveals blemishless surface in negatives or tranparencies . Such negatives / transparencies make ideal stuff for enlargement  or projection.

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K.Raman