My take on the photo.
* This was not an accidental picture or snapshot, it was planned and executed VERY well.
* It was taken from a leading plane.
* The P-39 was lightly illuminated from the leading plane.
* It was taken with black and white 400 (or +) ASA film.
* The shutter speed was probably between 1/8 and ½ second.
* The exposure must have been long enough for all of the guns to cycle once and for all tracer rounds to exit the picture frame.
* The exposure also must have been long enough for the propeller to make at least one revolution. (There appears to be a shimmer at the bottom of the arc, probably where the light source was reflected off of the prop, but the prop does not look like it only traveled a few degrees in this shot.)
* The guns and prop suggest a shutter speed of no faster than 1/125, probably much slower.
* The star exposure does make this photo very challenging. If they are indeed stars (and not dust as suggested) then they are very crisp.
* Star picture shutter speeds need to be relatively long, usually several seconds or even minutes. High number (400+) ASA B&W film however, could drop the shutter speed well under a second. It would be very difficult to get a crisp shot of stars from a vibrating aircraft with a long shutter speed.
* The real problem in this kind of a shot would be getting ENOUGH exposure of the stars with out overexposing the P-39. This suggest to me that the light source on the aircraft was VERY minimal, and not a giant floodlight.
* The other serious problem with this kind of a shot would be getting the P-39 and everything beyond (the stars) in focus with a wide aperture needed for such a low light photo. They probably used a relatively wide-angle lens and put the P-39 beyond infinity focus to eliminate a limiting depth of field.
My conclusion,
Probably mostly a real photo, they may have added stars in the lab.
eskimo
