Both of these photos of Madagascar were taken from the International Space Station (ISS) by astronauts using handheld digital cameras. The first photo was taken using a 10 millimeter lens, sometimes called a fisheye lens. The second was captured using a 58 millimeter lens, making this field of view slightly more zoomed in than what a human eye sees. For comparison, a smartphone camera usually has a field of view equivalent to a 24 to 30 mm lens on a Digital Single Lens Reflex (DSLR) camera.
Smaller lens sizes are helpful when astronauts want to photograph broad geographic regions on Earth. The first photo captures the entire island of Madagascar as viewed while looking down through the round center window in the ISS Cupola. The optical design of the small lens size causes Madagascar to appear distorted in comparison to a geometrically corrected map view. Spacecraft parts, including a docked Russian Soyuz capsule and the ISS solar panels, appear around the photo perimeter.
The second photo was taken using a 58 mm lens while the ISS was above a point on Earth’s surface about 580 kilometers (360 miles) south-southwest of Madagascar. From its southernmost tip to its northern coasts, Madagascar stretches 1,500 kilometers (1,000 miles). When viewed from the ISS altitude of 360 kilometers (225 miles) above Earth’s surface, the horizon is a bit more than 2,300 kilometers (1,400 miles) away.
The whole island is captured in both photos; however, the northern end of Madagascar is indistinguishable in the 58 mm shot due to cloud cover and the highly oblique viewing angle. Since the fisheye lens has a much wider field of view and was used when ISS was directly over the island (indicated by the spacecraft nadir label on the image), all of Madagascar was captured in a single but more visibly distorted shot.
Astronaut photograph ISS053-E-202989 was acquired on November 6, 2017, with a Nikon D4 digital camera using a 10 millimeter lens. Astronaut photograph ISS059-E-46155 was acquired on May 6, 2019, with a Nikon D5 digital camera using a 58 millimeter lens. Both images were provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The images were taken by members of the Expedition 53 and Expedition 59 crews. The images have been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by Andrea Meado, Jacobs Technology, JETS Contract at NASA-JSC.