There were many lenses for aerial photography. A lot of them. Some companies switched to their production in times of need from other, related fields, for example from the production of binoculars (the case of British Aldis). They were also produced under license - often they weren't even signed and could only be recognized by serial number or small differences. According to the serial number starting with "UU", in this case it would be a Serrac, which was used for espionage and aerial photography.

• For these purposes, fast-aperture optics with as much coverage as possible were used to photograph an area as large as possible even in bad lighting conditions. There was no need for small aperture, let alone size and weight. The lenses were mounted to the bottom of the plane (well, where else, right) and the combination of large aperture and large coverage usually had one thing in common - they were all huge and heavy beasts. They were often paired with giant shutters and automatic film feeders, which were measured in kilometers.
• The films were used in a variety of sizes, but the common denominator tended to be high fineness (called lines per millimetre - lpm), sharpness and increased contrast. The use of special developers, etc. was no exception - it was not at all suitable for normal photography.

And from the exterior of this particular one, he was spying and shooting really hard (or maybe the British pilots were dropping him from the plane when they ran out of bombs). However, despite having obviously done a lot of flying in his long life (no pun intended), he's perfectly fine - yuck on the outside, huzzah in the inside!

• The oddity is the minimum aperture of f16 - that's quite small for a large format lens and some, mostly older landscape lenses barely started at that aperture.

I'm sure he could have a story to tell - what wars did he take part in? Which battles did he witness? Who did he photograph and who did he fall on his head? Or did he fool us and spend decades in the potato cellar where the quartermaster dumped him? I know one thing for sure, though - I took him for a walk and we took pictures - but this time, against his habit, he took pictures from the bottom up. And he was good at it, old man.