As a landscape photographer, I’ve always been captivated by images of moving water. By varying the shutter speed one can create many different effects. A very high shutter speed can ‘freeze’ the moment…
…and a longer shutter speed can create a sense of flow or movement in the photograph itself.
If conditions are right, when the light is very low, one can make exposures of up to several seconds, and with this shutter speed it’s possible to create images where the water movement becomes so smooth as to look like silk.
However, making shots like this in the daytime can be very difficult as it requires the use of very dark neutral density filters. I’ve been wondering if there was a way to duplicate this effect using the computer. Yes, Photoshop‘s filters come to mind and with PS almost any effect is possible, but I wanted to use the information in the image itself. My first thought was to capture a series of images and combine them using something like Autopano Pro. I use Autopano for making panoramic images, and I also use it for combining individual images into HDR composites. With that in mind, I made the following image from 31 separate images, combined into one composite.
Unfortunately, it didn’t have the effect I was looking for. One of the features of Autopano Pro is that it has very effective ‘ghost removal’, so if something exists in one image but not another, Autopano automatically selects the best image from the lot to feature that particular area. What happened here is that the wave action from the 31 images was parsed into making one image rather than combining them together.
Undaunted, I decided to try again, but this time using the LR/Enfuse plugin for Lightroom from Timothy Armes. The LR/Enfuse plugin is designed to take individual images created for making HDR composites and combine them into one image, but it doesn’t have the ‘ghost removal’ feature of Autopano Pro. In this case, that’s a good thing.
Here are two composite images, processed identically. Both are made from 18 individual images (six sets of images at +1/0/-1 exposures). The first was combined in Autopano Pro, and the second was combined using the LR/Enfuse plugin. Both were finished identically in Lightroom.
Finally I achieved the effect I was looking for. It’s not exactly the same as the effect achieved using neutral density filters or with shooting in really low light, but I like the sense of movement imparted by the second image that’s missing from the first and I don’t have to manually calculate exposures. I have found that shooting more images is better than shooting fewer images as each image adds a ‘layer’ to the final composite. I usually bracket my exposures when making this type of image, but it’s not entirely necessary.
Here are a few more examples:
Now go out and make some photographs!!
P.S. Autopano Pro has an excellent image alignment feature, and using that I have sometimes made HDR image composites hand-held. LR/Enfuse also has an image alignment option, but it’s not as powerful. If you’re going to do work like this you really need a sturdy tripod.