Enhancement of gun camera pictures involves a
whole slew of techniques. We have to correct for double or multiple
exposures caused by the sudden change in direction from a gun firing
while the shutter is open. There is the blurring from motion of plane
and target or plane and ground. We can fix a certain amount of out of
focus problems and do a great deal to help the poor exposures forced
by the camera having only two f-stops. One for above the clouds and
one for below and the pilot had to set it before takeoff based on
weather reports and flight plan. We can elliminate dust and scratches
and do a little to help the rather common messed up frames caused by
a lack of robustness of the camera where a sudden move can slow or
freeze the rotating shutter.
Once the methods are worked out, we plan to
enhance and restore entire sequences. Here is a before/after shot of
a medium resolution scan of about half of a 16mm frame. Note the blur
and double exposure effect in the original. A good reference point is
the little elongated light spot on the ground behind the closer wing.
In the processed image this has become a small rock or other light
colored spot. Note also the wing tip emblem. This He-111h may have
been a "target of oportunity" for quite a while since there are
pronounced footpaths around it. I wonder how many times it was shot
up by low level hunters returning from bomber escort?
Here is an un-enhanced frame that doesn't need any
work besides a little scratch removal. One must be careful in
removing what looks like dirt and examine the film sequence. It might
be part of the plane!