Focusing while fully zoomed in assures best clarity when you zoom back out to see a larger field of view. (Courtesy of Peter Girguis, chief scientist, Harvard; Funding agencies: NSF, ONR, NOAA; ©Woods Hole Oceanographic Institution)

By lining up video cameras on either side of the sub during a transit, scientists can record a rolling view of the seafloor five times wider than Alvin’s basket (Courtesy of Peter Girguis, chief scientist, Harvard; Funding agencies: NSF, ONR, NOAA; ©Woods Hole Oceanographic Institution)

Use the Iris setting on the camera controller to adjust exposure. In general, it is easier to "rescue" under-lit images than images that are too brightly lit. (Courtesy of Peter Girguis, chief scientist, Harvard; Funding agencies: NSF, ONR, NOAA; ©Woods Hole Oceanographic Institution)

The key to capturing good images and video underwater is lighting. Alvin’s new lights and ability to move sideways make it easier than ever to set up a great shot. (Courtesy of Peter Girguis, chief scientist, Harvard; Funding agencies: NSF, ONR, NOAA; ©Woods Hole Oceanographic Institution)

Chris German, outgoing chief of the National Deep Submergence Facility at Woods Hole Oceanographic Institution, has prepared guidelines for making the best use of Alvin’s improved lighting, imaging, and video data collection systems. The guidelines are based on the experience of scientists who participated in the Science Verification Cruise (SVC).

One set of suggestions covers positioning, focusing, aperture-setting, auxiliary lighting from the manipulator arm, and photo documentation during a transit along the seafloor (Primer: Sub Sea Video Imaging (pdf)).

The second set of suggestions deals with processing images and video after a dive (Primer: Post-Dive Video Recommendations (pdf)).

Also available will be video clips from the SVC so that scientists who will be working with Alvin footage can familiarize themselves with the file types that will be coming from the sub. Dive video will come in both the .mov format (the original from Alvin’s cameras) and .mkv format (a “proxy” version that the SSSG technicians will produce after each dive). The proxy files, being highly compressed, take much less time to copy and less space to store while still providing high-quality images. However, viewing them requires software many scientists may not have yet, such as the freeware VLC.

German recommends that scientists install VLC and practice using it with a sample .mkv clip before they leave home (Sample video (mkv)). Here’s a short portion of the same scene in the original .mov footage, so you can compare the quality of the two formats (Sample video (mov)).

He also asked that anyone with additional suggestions about using Alvin’s imaging systems contact him at cgerman@whoi.edu so the guidelines can be updated.