I am now on my second run through Stalg Luft and the escape commitee have tasked me to take a photograph of the secret rocket the nazis are building in the corner of the camp. I've found a perch on the roof of the nearest building where I can see the rocket and it's launching gantry very clearly. I have the camera in my inventory, but I cannot figure out how to use the bloody thing to take a photograph of the missile. This is really bugging me as it's not even a part of the game that should be holding me up. I've found the damn thing, but can't figure out what buttons to press to take the picture. Can anyone help?