Compositing Wildlife Photographs
Though it may not be so apparent when hiking the many miles of trails, the open spaces around Mt. Tamalpais are teeming with wildlife. The Marin Wildlife Picture Index Project is one tool that Marin County researchers use to quantify the activity and populations of animals on public lands. This network of motion-activated cameras produces thousands of images which are carefully sifted through and categorized by local volunteers. The results of this project give researchers a way to determine the abundance of species and overall health of the ecosystem.
I first heard of the MWPIP when looking for volunteer opportunities I could squeeze in to my busy work schedule. I joined other community members in several indexing sessions in which, after a short orientation, we were each assigned to review specific image sets from cameras in the network. When an image contained an animal, we referred to the provided guidelines to properly identify and catalog it.
Recently, the Marin Municipal Water District sent out a call for volunteers who might have the skill set to combine multiple images from single cameras. The resulting composite images would showcase the variety of wildlife captured by each camera.
My own photography occasionally necessitates the creation of a composite image, usually for images captured at night, where I might need to combine images of the sky and the landscape that are taken with different settings. In the case of the wildlife picture index, I would be combining images of animals who had passed by the same camera at different times. I thought this would be a fun way to contribute to the project.
Because the position of the camera doesn’t change much, there are only a couple of other challenges in compositing these images: the time of day and the position of wildlife in the camera frame. For the first, shifting sunlight and shadows complicates the impression that the animals are sharing the space at approximately the same time. For example, it’s difficult to composite animals who are in full sunlight into a shady scene, and vice versa. This makes shots taken at night much more natural candidates for compositing, even though shots taken during the day have more detail and color.
The other issue has to do with wildlife occupying the same parts of the frame. The smaller the animal is and the less its silhouette crosses recognizable parts of the background, the more leeway there is in nudging that animal into a slightly different position. But for the most part, when animals cover the same area, one or the other has to be chosen in their natural position so that the effect of the composite is convincing and true to life.
Communicating these challenges to the water district aids them in selecting the images to be composited. Once I have their selects, I can do the compositing work. I load all of the images into Photoshop layers, carefully align and color correct them as needed, and mask each animal one by one. Finally, I share the final composite images back to them. The process has been going smoothly and seems to improve with each new batch.
It’s been really cool to work with some of the best images from the wildlife cameras to create these composites, and the results range from surprising to humorous. I love that there are volunteer opportunities like this where I can put my technical skills to good use.