The Apollo 13 mission to the Moon occurred 50 years ago, and there have been a number of interesting websites to document this anniversary. One such example is linked below, which allows you to follow along with the mission, as it occurred in real time, with communications audio, annotated transcripts, commentary, and photographs. You can fast forward to any part of the mission you like.
As most of you know, the Apollo 13 mission experienced a severe incident en route to the Moon, which significantly crippled the spacecraft, and the crew had to abort the planned lunar landing and return to Earth under very challenging and dangerous conditions. Instead of entering lunar orbit, the spacecraft passed once around the Moon to slingshot back to Earth. A number of interesting photographs were taken during this mission, despite the challenging conditions. In looking over the website linked above, one that caught my eye was a photograph of the crater Tsiolkovskiy, a very nice crater on the lunar far side, named after the scientist Konstantin Tsiolkovskiy, famous for developing the equation that bears his name (Tsiolkovskiy rocket equation) that relates propellant mass and exhaust velocity to the impulse delivered during a rocket burn.
I had long been aware that all of the Apollo mission photographs had been scanned, and were available on the web. Most of the versions you will find are provided as processed images, and are only available as 8 bit files. I discovered one excellent source, however, that provides the raw film scans, unprocessed, as 16 bit tiff files. That source is below, and is a collaboration between NASA, the Johnson Space Center (JSC), and Arizona State University (ASU).
Particularly interesting is reading about the scanning process. There are a variety of file formats that you can download, but only the raw film scans are unedited. These images are all in the public domain, and you can process and use the images for non-commercial purposes, including personal use, education, or research. I downloaded the raw film scan of the image I had been searching for of Tsiolkovskiy. The raw film scans are very large files, about ~1.3 GB for a single file.
The image was taken with a Hasselblad medium format camera (70mm film), and a 250mm f/5.6 Zeiss lens. The film used was Kodak Ektachrome SO-368, which was custom made for NASA. No details are given about the exposure, but it's very noteworthy how dark the raw film scan appears (see below)! I then did a series of adjustments to the image of the raw scan, and cropped and rotated the final version. In the next post, I will give a brief outline of those procedures. You can find numerous other processed versions of this image on the web, and there is nothing remarkable about mine. This was simply done out of interest to look at the raw film scans, and the historical context given that the image was taken almost exactly 50 years ago. Click for larger size of the second image.