How much time did take a photo recon pass?

[Romani]

In WWII recon airplanes did high altitude high speed passes using motion picture cameras, but the procedure in WWI must have been rather more long and complex.


Some ace whose name escapes me said that enemy 2-seaters should be attacked when the observer had its attention concentrated on other duties other than looking around like artillery spotting, or in the subject of our interest, taking photos.

I can see that taking photos early in the war using handheld cameras hanging them over the side of the airplane must have been a long and cumbersome process, given than an airplane of the time moving at the modest speed of say, 120 km/h moves 2 km per minute, the observing airplane must have been hovering in circles to take photos of a particular spot of ground, like the site of a concentration of troops or an artillery battery. Photo mapping the trench positions would be fairly straightforward , with the airplane flowing straight and level along the stretch of trenches while the observer just took snaps as fast as he could.


But later in the war cameras were mounted inside the fuselage, aiming downwards at an angle through the bottom of the airplane (if I am not mistaken cameras aiming sideways of the fuselage are a WWII development).

So the pilot presumably flew straight and level at a moderate speed over the target area and the observer looking through a visor and working the shutter.

So unlike a motion picture , the end result it would rather be like a slide show. Though the difference must have been minimal, one has to pity the poor photo interpretation analysts that had to piece together a picture (pun not intended) with the partial shots with gaps between taken by the earlier handheld cameras, considering this was black and white film, it must have been like a color blind person trying to assemble a puzzle.


But I digress... I wonder how long under typical circumstances would it take for the recon plane to make a photo run... I know the answer is "depends of what you are trying to photograph" I don't know how aerial photo mapping works, but I figure that making a map of a few kilometers long sector of trenches must have been a tedious and time consuming task, involving repeated passes. So in particular I am asking instead of an "area target" like this example, how long would it take to make enough pictures to be useful of a "point target" like an artillery battery, an ammo dump or a headquarters.

It all boils down to this: how long has the recon plane have to fly straight and level with the observer busy taking photos and unable to man the machine gun? a few seconds? 30 seconds? a minute or two?

Just want to know if in presence of enemy fighters, a skilled recon pilot could evade them just for the few seconds necessary for taking the photos and then fleeing for home, or is the procedure is so time consuming that it cannot be undertaken in the heat of combat, so the observer has to choose between using the camera or the machinegun.

If the procedure takes more than a few seconds, then obviously it could not be undertaken as long as there are enemy fighters over the target area (and willing to engage, I must add)

[Epee]

The Germans developed a method using the Roland CV-series that envolved high altitude, fixed speed flight along the desired axis of photography coupled with a special camera. The camera consisted of a lens and winder that pulled film across the lens at the proper exposure speed. This resulted in a huge panorama the entire length of the film roll. These planes did not carry an observer or weapons for these missions but depended on altitude, speed and lack of warning for defence.