It’s the deepest part of January on the prairies. Usually this means that everything is frozen solid: vehicles, the road, lakes, rivers, photographers, etc. 😉 But this year in our neck of the woods, there is so much water flowing from the Dam that the river hasn’t froze over – which is a rarity to say the least! Much to the chagrin of local ice fishermen who can’t really get on the weak ice, it does provide a chance for some slow shutter speed river photography.
We call it “shutter speed” but really, it’s a unit of time. The same way a lightyear is a unit of distance, not time. Shutter speed is the time duration that light is allowed to come through the lens and light up either the film or the digital censor. The longer this time period takes, we call it a “slow shutter speed.” And oppositely, the shorter this time period takes, we call it a “fast shutter speed” – but really, it’s more helpful to think in terms of time and not velocity. If I want to stop a hummingbird’s wings, I need a fast shutter or, a quick time – only like 1/8000 of a second! But to slow down running water to make it look really silky and creamy we need a longer time (a slower shutter speed) – a full second or more is nice!
For this shot, I had a bit of a gong show. I went yesterday when it finally warmed up a bit and we had lots of light. Turns out it was too much light for what I wanted to do. I wanted a full second of exposure time, but I couldn’t get it. I had my camera setup on a tripod at 16mm, ISO 100 and f/22 (smallest aperture I could get at 16mm). And the problem? The longest duration I could get my shutter at was .5 seconds. Immediately you can see the problem this creates. There is just too much light. The water is blurred (somewhat) but the snow and sky and everything else is completely blown out making it look like… well, crap.
So, what to do? My aperture was constricted as much as I could get it, the ISO was in the toilet and I couldn’t get the exposure. There were 3 options to make this shot work and only 1 was available to me at the time.
Option 1: Neutral Density Filter. If I had one of these for my lens, I could have “dialled in more darkness” allowing me to dump down even four more stops of light! This would have allowed for a longer shutter time and made the scene have an even more silky look in the water. Alas, I don’t have an ND filter, so option 1 is out of reach.
Option 2: Come back later. I could have waited until the sun was close to setting and the place where I was at to go blue from lack of light. This probably would have allowed me to get down a few more stops of light, but I also would have lost the light in the over all scene. Plus I had to parent, so option 2 didn’t work.
Option 3: HDR. This was the only option I had to try to get the shot I wanted. Longer shutter time for blurry water, yet shorter shutter time for proper exposure of the overall scene. This option was the only one I had available. And it worked out OK.
I didn’t really intend to make an HDR image, but it was the only way to control/manipulate/tame the light I had to work with. I took a range of exposures (all at f/22) from .5 seconds up to 1/15 of a second. The last image at 1/15 had a nice histogram with no clipping whereas the .5 histogram looked like an L had fallen on it’s back! I probably could have gone down one more stop to get some more of the darker areas. But that’s why there’s next time. 😉