On this week's episode of Still Untitled, we talked at length about space exploration and the incredible achievements of NASA and the Apollo astronauts. In discussing the world's remembrance of Neil Armstrong, Adam brought up this article from the American Copy Editors Society about photographs taken during the first moonwalk. Armstrong bore most of the photographic responsibilities during the mission, so as a consequence most of the photos of actual moon walking are actually of Buzz Aldrin walking around and performing experiments. (Another minor controversy lies in the fact that NASA edited the famous portrait of Buzz before releasing the image to the media.) Wading through this photographic pedantry brought me to NASA's Apollo 11 digital picture library, an amazing public resource which hosts downloadable high-resolution versions of every photo Armstrong and Aldrin took on the moon. Photos like this one of Aldrin's footprint make for awesome desktop or tablet wallpapers.

The sharpness and clarity of these images can be partly credited to the camera used on the lunar surface: a modified Hasselblad 500EL camera called the Hasselblad EDC (Electric Data Camera). Hasselblad, which makes medium-format cameras, has a long history of working with NASA to provide film cameras for missions as early Mercury-Atlas 8 in 1962. The EDC, first tested on Apollo 11 and then used in subsequent lunar missions, was modified specifically to cater to use in spacesuits on the moon's surface. Here are some of the more notable modifications that made the camera so unique:

Unlike the black 500EL, the EDC was silver to make it more resistant to temperature changes on the moon (being in full sun vs. being in shadow, a range of -65 to 120 degrees Celcius). But the cameras weren't actually made of different materials--they were just stripped of leather finishing and given silver paint jobs. The 70mm film magazines were painted the same way. Lubricants used in the making of standard Hasselblads had to be removed so they couldn't boil in the vacuum of space.

Attached close to the film plate was a glass sheet called a Reseau-plate, which superimposed the grid of 25 black crosses onto each photograph. The crosses were used to determine angular distances between objects in the frame, as in with aerial photography. Conspiracy theorists have pointed to "mistakes" in lunar photographs where an object such as a spacesuit seems to pop in "front" of the crosses. This is easily explained by highlight bleeding that naturally occurs in film overexposure.

The EDC on Apollo 11 had a Carl Zeiss Biogon 60mm (f/5.6) lens designed for NASA with a polarized filter. 60mm was chosen to avoid lens distortion in the photographs.

The standard mirror waist-level viewfinder was also replaced by a square gridded eye level finder since astronauts could not look down from their spacesuits to take a photo. They either held the camera up to their helmets using a handle and look through a simple sight (pretty ineffective, and the reason why many of the moon photos are framed "unprofessionally") or mount the camera to the chest of their spacesuits and press a button by directing their chest in the direction of the subject. This is actually how Armstrong shot the series of photos used in this stunning lunar panoramic. The Apollo astronauts were given test Hasselblads to take on family trips to practice shooting with these restrictions.

Hasselblad released a commemorative "20 years in space" version of the 500 EL that resembles the camera used on the Apollo missions, and they occasionally pop up on eBay. Collectors of Apollo artifacts will likely never get their hands on the real deal, though, as Armstrong and other moon photographers actually left their Hasselblad EDC cameras on the surface of the moon to lighten the load for the return mission. All 12 HEDC cameras used to shoot moon walks are still there, collecting moon dust.