Technology

What is it?

 Here's a hint.  This knob is on the lower right in the picture above.

Not quite completely caught in the lower left of this photo is another hint:

FLIGHT DIRECTION

It is an aerial camera.  My grandfather used it in the mid-part of the last century.  

I am trying to reclaim the lenses from it.  It is proving to be a challenge.  Someone said to me, "It's still good!"  Well, sort of.  It probably could be made functional with a little effort.  There is some condensation between the lenses that would have to be dealt with.  But even if it is restored to its former glory, is it still good for use? What was it made for?  In other words, what was its function? Are aerial cameras still used today?  If so, how are they the same and how do they differ from this one that took still pictures on film?  Are there any other technologies that fulfill this same function?  What benefits do the new technologies have over this one from the 20th century?