Slowing Down Time

Bit of a slow day today, not feeling up to a major walk or hike, but I did venture out to do a bit of experimentation. One of the things that a camera is capable of is effectively slowing down time, by judicious use of the shutter. Essentially, you leave the shutter open for a few seconds, and during that time, the image continues to 'paint' itself onto the sensor (or film for those of you with a sense of nostalgia).

Of course, as with many things, this isn't as easy as it sounds because any exposure is based upon three factors:

1. The ISO setting (analogous to the film speed of old) which is how sensitive the sensor is to the incoming light.
2. How wide the Aperture is (the size of the opening of the lens through which the image gets to the sensor).
3. The shutter speed, or how long we let the sensor see through the lens' aperture.

My goal was to make an exposure that allowed the shutter to remain open for multiple seconds, 4 seconds being the optimum in this case. To do that, I had to lock the camera ISO to its lowest setting, which in the case of the Sony NEX 7, is ISO 100. This allows me to use the longest shutter speeds. In addition, I set the aperture of the lens to f16, which is a fairly small opening, thus getting a longish shutter speed. (This is because the small opening requires that the shutter stay open for a longer period to give the appropriate exposure.)

OK, but, it is still not a long enough exposure time, as the camera does the necessary calculations and comes up with a shutter speed of 1/20th of a second. Because I want the camera's shutter to stay open for 4 whole seconds, I added what is called a variable ND (Neutral Density) filter on my lens that can be rotated to add an increasingly dark, neutral cast, thereby requiring the camera to keep the shutter open longer.

At this point, you may be wondering "what is the point of all this"? Well, my goal was to take an picture of the coast in which the surf would 'paint' it's movement on the image during those 4 seconds. Done correctly, this yields an image in which the surf looks more like fog, or smoke. Unfortunately for me, today, there is almost no surf whatsoever, but I gave it a go nonetheless. Here are the results:

 

This is the image unprocessed.

 

Here, I've done some processing to maximize the detail and contrast range etc.

 

And here, finally, is a B&W image of the same.

As I pointed out, almost no surf, so very little of the effect I hoped to capture. I am also disappointed in the ND filter itself (it's a cheapie, and unfortunately has a nasty colour cast as you dial it up, which is why I converted to B&W). I do have another, more expensive one that should perform better, but it's a little unwieldy to strap onto the smaller cameras I now use. Next time, I think I'll give it a try though, and also wait for a day with some decent waves. Ah well, that's life on the edge.