Virgin for the light

Every once in a while, a friend and I get caught up in a conversation where we debate where the technology will take us. One of the current topics is the Shutter+Mirror mechanism in modern DSLRs.

The shutter mechanism, with its sliding-curtain and flipping-up mirror is very well known to any photographer who has been around for some years, as it is an exact adaptation of the mechanism used in regular film SLR cameras. Its main advantage is that it allows for composing and metering the subject through the very same lens that will take the picture and then, expose the sensor in a controlled fashion. The mechanical shutter also allows for having a completely clean sensor, "virgin" for the light.

The drawbacks are obvious, being a mechanical device, to achieve the speed needed can be a complicated fate. The mirror mechanism is also somewhat complicated and it accounts for the so discussed "photographus interruptus" where the mirror ocludes from the photographer the actual image being taken. Moving parts are delicate and noisy.

Point and shoot cameras use a less expensive and simpler solution, having a constant opening that allows for the light to hit the sensor and hence view, meter and continuously compose on the LCD screen. This alternative is superior in the sense that it allows for high above and under-the-hip composing as well as being able to judge the noise level on the sensor. When the picture is taken, the CCD device is cleared electronically and the exposure process begins. After the exposure time has elapsed, each pixel is transferred, "stopping" the process.

In contrast with the Diafragm, which is optically needed, there is no doubdt in my mind that with time, this "electronic shutter" will be perfected and will eventually replace the mechanical shutter even on the most expensive cameras.

As it happened with the electro-mechanical sequencers on our washing machines that were continued to be widely used until just recently when replaced by Microprocessors, mechanical shutters are so mature that we will continue to use them for years and they will make for good background noise. It always make me smile when some "sound effects" genius uses an outdated shutter noise and you can hear the whirr of the motor-drive advancing the film.

For more info: Huba Rostonics is a Florida-based Photographer. He is constantly looking for new things to put a frame around. You can check his work at http://www.rostonics.com, you can also follow Huba on twitter @ http://www.twitter.com/rostonics.