Photographing the Yuba
I recently drove out to our local Wild and Scenic River, the Yuba, and wanted to share the workflow I follow when using my drone for photography and orthomosaics.
The two most important factors I think about when photographing are location and purpose. These will likely naturally flow from each other. For most of my projects, the purpose has been experimentation with the drone, although some projects have had more specific goals (i.e. documenting tree work in South Lake Tahoe).
Once I have determined the location and purpose, I’ll want to find the best date and time to fly. For most purposes, midday (as close to solar noon as possible) will give you the best pictures with smallest shadows. For some locations, such as the Yuba river, midday might be too crowded. For this flight, I went early in the day (6AM) to avoid having to fly near other people.
To prepare for a flight, I use a planning checklist to ensure I have everything I need. I’ll start planning the flight by looking at existing aerial imagery and marking the area I want to photograph. For some projects I might use the property lines to mark the flight, but for larger areas, like the Yuba River State Park, I’m often flying a much smaller section of the area.
After ensuring the flight apps I use have the proper areas loaded and ready, I start gathering and charging the various things I will use for the flight. The first thing I check is that my memory card is installed in the drone and has enough space for the upcoming flight. Next, I will charge one or both of my drone batteries and the remote control. I try not to store the batteries fully stored, so if I’m only flying a small area I might not fully charge the second drone battery.
After all the batteries are charged, I pack the drone in its bag and make sure the landing pad is still in the bag. There’s nothing worse than trying to fly and realizing you are missing something crucial! Because of the summer heat at midday, I also pack a sunhat, a snack, and several water bottles. For the early morning flight of the Yuba, I brought plenty of water, but also my morning tea.
Once ready to fly, I’ll review the purpose of the flight and check a “shotlist” if I’ve made one. Finally, it’s time to fly! I start the flight by checking all the controls and camera settings. After taking a few pictures of the site by hand, I land the drone and launch the mapping apps that will fly the drone autonomously.
After the mapping flight is complete, I check the photos on the memory card to make sure the focus and exposure are ok. Then, I might fly manually again and take a few more photos with any remaining battery before packing up the gear and heading home to process the images.
I use an open source project called Open Drone Map for my orthomosaic creation (I’ll dedicate another post to the science and math involved in creating a single top down image from the 200+ stills taken during the flight). After a few hours of processing in the cloud, I get an email notifying me that the project is complete, and I download and inspect the image using QGIS and Photoshop (I crop and adjust the image in photoshop before sharing with any project collaborators).
The end result is a new “birds-eye view“ of the river which can provide new perspective on a favorite river spot. Using the flight path again and again in the future will allow for comparisons of the water level throughout different years and seasons. If you haven’t already, checkout my post on using drones for comparing the same landscape before and after tree work for a demonstration of that temporal comparison.
