Central Texas has had a lot of rainfall and flooding lately. One of the results of this rainfall is that the rivers are flowing at much higher rates that normal. North of the town I live in, there is a low water dam on the South San Gabriel river. It typically is little more than a big stream, and in the summer, people use this area to play in the water and escape the heat. I noticed from the road bridge near the dam that there is a lot of water flowing over the dam so I arranged to get back to this place with my tripod for some long exposure photos.

The first photo I took was mainly just gauging for exposure so that I could make the adjustment for adding the 10-stop ND filter. But it also provides a good before reference for the long exposure. There are also a couple of kayakers who where exiting the water while I was setting up.

What I didn’t realize when I took this photo is that I still had my polarizer attached to the lens. So, you can see that the sky is darker is spots away from the sun and the colors are a bit different than the rest of the photos below. This also had the effect of reducing to my initial exposure beyond what it would be without the polarizer. Ordinarily I would multiply the shutter speed by 1000 when putting on the 10-stop filter. I had to guess a little to account for the polarizer, so I reduced the aperture from f/10 to f/13 (about 2/3 of a stop) and set the shutter for 20s (about 1/3 stop less than 25s).

Below is a screen capture from the PhotoPills app that has an exposure calculator for using ND filter. I went back and checked my work on this and it seems that I got it about right.

The image below shows the same scene at 20 seconds exposure compared to 1/40 of a second above. The histogram indicated that I got the data without clipping. So, the polarizer added about a stop of exposure reduction, which is what I have read.

The waterfall blurred out nicely and the calmer water smoothed out to look like ice. You can see that the water is not very deep here as the rocks on the bottom are visible in the long exposure.

I also tried getting low to the ground to have the pebbles as a foreground. I was shooting in deep shade and it was difficult to get a good exposure for the foreground and the trees in the background that were brightly lit by the late afternoon sun.

The trees are starting to turn for autumn and I think that they make a nice swath of warm color across the image between the cool gray water and blue sky.

I was able to get the range of the entire scene in one shot, so in Lightroom I put a graduated filter over the sky and trees and brought the exposure down in this part of the image. Then I boosted the exposure of the entire image to try to achieve a more balanced exposure for the final image. To achieve this in camera I would need to attach a graduated ND filter over the bright part of the image. I don’t currently have one of these but I am considering purchasing a filter kit soon.

I climbed up on the dam to see about getting some pictures and I noticed a large chunk of concrete on the lower left that I could climb down on and set up my tripod for a close up shot of the cascading water.

The below image was taken while perched precariously on the concrete block. It shows a long shot across the spillway with the water motion-blurred.

The bright background and shaded foreground were a challenge with this shot as well. My main nuisance is a brightly lit area of limestone directly across the water. I actually knocked that down in Lightroom quite a bit and it still sticks out and distracts from the focus of the image.

My next point of interest was the brightly lit trees with warm fall colors reflected in the pond. I tried a variety of ways to get this and the waterfall in the same shot, but found that I would need to be able to hover to accomplish this. I eventually settled on the following composition.

Composition-wise the spillway dam provides a line across the scene, but it kind of goes in the wrong direction. I would have like to have gotten farther out on the dam to shoot around the plants on the right, but I was already standing in the rushing water and didn’t want to go any deeper than this and risk slipping with my camera gear. I do like the reflections that I got with the trees.

I may come back to this in a week or two when the water slows down a bit. There is a rope hanging in the trees across the water and I would like to try to use that as a compositional element along with the autumn leaves to imply that summer is over.

Thanks for reading. Leave a comment if you have feedback or questions.