There were loads of aerial photography lenses. Shitloads. Companies jumped into making them when the war machine needed 'em - even if they'd previously done something else like binoculars or other optical thingies (hello Aldis!). Or they pivoted from commercial optics, either partly or completely - cue Dallmeyer, Wray, Ross, TTH, Burke & James and the others from the lens gang. Production was frantic and markings were... let's say, "optional". Sometimes you'd identify a lens by number, symbol, or a tiny design quirk. Sometimes you wouldn't ID it at all.

• Lenses came marked with all sorts of anything - for example a crown, one of the many RAF symbols.
• Dallmeyer also sometimes engraved a stylized J.H.D. (for founder John Henry Dallmeyer) in every possible way: with dots, without, in a circle, freestyle.
• Then there were (or weren't) codes like AM 14A/XXX-X. "AM" stood for Air Ministry, the 14A bit was the start of the contract code, and the rest... in Dallmeyer's case, those digits often matched the aircraft part the lens was mounted on - usually a Spitfire or later a de Havilland Mosquito.
• Some specimens had the W↑D symbol - meaning they belonged to the War Department.
• And during the war, Dallmeyer got fancy and cooked up their own anti-reflective coating. They called it Dallcoat, which was magnesium fluoride (MgF₂) applied on glass. Near the end of the war you'd sometimes spot lenses with a "DC" engraved on them - that was your cue.
• Oh, and serial numbers? They started with two letters, often your only hope of figuring out who the hell made that. "UU" was Dallmeyer, "TT" Taylor, Taylor & Hobson, "VV" Ross, "No." or "EE" was Aldis and "NOC" = National Optical Company - a TTH offspring churning out war glass.

The 360mm (14") range was mostly covered by Dallmeyer, 500mm (20") belonged to Aldis and the Big Bertha - 900mm (36") - was carried by Wray. Not that it really matters - everyone built everything, lenses got swapped like socks and wartime production wasn't exactly a fan of order.

In the darkest days of Britain and Europe, Dallmeyer did something that, seen through today's market logic, feels almost unthinkably chivalrous. Rather than splinter its production capacity in the endless chase for profit (not that they were running a charity though), the company focused fully on supplying the military effort. No double-dipping, no hedging bets between the front line and the commercial high street. They tightened operations, prioritized the war machine and even took time to boost national morale. Below are excerpts from wartime press materials (mostly sourced from an excellent reference linked here):

"In total war it is impossible to have tanks and cars, guns and lawnmowers, aeroplanes and furniture... Dallmeyers are engaged in the battle of the factories, so you won't expect to be able to buy Dallmeyer lenses."

During the pre-Christmas seasons of 1939 to 1944, the factory regularly released upbeat little notes into the advertising ether, confidently predicting the war would soon be over - until eventually, they were right. In the September 1945 issue of Trade Bulletin magazine, they finally nailed it: a half-page ad appeared with a headline that said it all, with all the relief of a deep exhale - PEACE.

"The door is now unlocked, and Dallmeyer lenses will soon be once more available for distribution by the photographic and cinematographic dealer."

Alright, enough history lessons - let's get back to the actual shooting. For aerial reconnaissance, they used super-fast optics with the widest possible coverage, so you could snap as much ground as possible even when the light sucked and weather was British. These lenses were mounted under the plane (where else, seriously?), and the combo of speed, focal length, and coverage meant one thing: these were massive, heavy beasts. They often paired with giant shutters and automatic film feeders that churned out film by the kilometers. Fucks given about size or weight: 0.

From the looks of this particular Serrac of mine, he was spying and shooting 24/7 (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 ouside, huzzah on 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. Clearly, for aerial photography, aperture was more important, so they usually didn't stop down too much.
• Oh and beware, updates!! For years I lived under the foolish assumption that, like the Spitfire, I was carrying an f4.5 Serrac on my shoulders, but then I happened to notice that I was a twat and probably had the less common f5.6 version. Apart from that one trace of luminosity the difference is very likely to be tiny or even non-existent.

Surely he could tell - what dogfights has he participated in? What battles had he witnessed? Whom did he photograph and upon whose head did he fall? Or maybe it was a deserter hiding for decades in the potato cellar, tossed there by some quartermaster? 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. He doesn't like the backlight at all, but otherwise he was still good, old man.