some thoughts on contrast

Digital HDR for contrast in 2013

Toronto. The other day as I watched a 1938 movie with Boyer and Lamarr, I got to thinking about contrast. The movie I watched was a dark, contrasty,  flick called ‘Algiers’. Some scenes had inky black shadows, others nearly washed-out highlights.

In the 19th century, most efforts on photography went into increasing the media’s sensitivity and trying to capture colour. Tripods, steady subjects (or sturdy supports) and lots of  sunshine were key ingredients for the day.

In the 20th century, the goals for film were: greater sensitivity, softer contrast, higher definition, and full colour. In general, the lower the sensitivity (ASA or as we know it, ISO), the higher the resolution, and the greater the contrast. One solution was using physically large cameras to expose glass plates or film. In the early days of experimentation with minicams, the 35mm cine film traded resolution for speed and hence softer contrast.

By the late 1930s, when the minicam revolution was in full swing, 35mm movie film had changed to low sensitivity and high resolution making scenes very contrasty. The mid 20th century was spent devising developers touted as reducing grain, softening contrast and offering ‘push’ processing to increase the sensitivity of the film by a stop or so.

Meantime, manufactures researched ways to capture colour, reduce grain, soften contrast and increase sensitivity in the off the shelf films. On my last outing to BC using film, in the summer of 2002, full colour negative film with an astonishing ISO 800 rating was available everywhere. The film’s colour accuracy, gentle contrast, fine grain, and sensitivity   made it the go-to choice for my Leica.

A decade later, digital HDR for contrast was in full swing. On-board computing power allowed the camera to combine rapid shots to give the typical look to HDR images such as the tree above which I took late at night by available light (and a tripod) at ISO 400. The trip to BC in 2002 was the last time I used film.

This entry was posted in history and tagged , , , , , , , . Bookmark the permalink.