Oswald in the doorway: the blog of the Oswald Innocence Campaign, by Ralph Cinque

Why should anyone accept the lighting in the limo in the Altgens photo? Why would Kennedy and Connally be all light-up but Kellerman obscured in dark shadow?

It wasn't that way at other times. This is from Main Street, which has the same orientation to the sun as Elm. 

The image of Kennedy in the Altgens photo is fake. He was NOT yet shot in the throat at the time of the Altgens photo. There isn't a snowball's chance in Hell that he was shot in the neck already by then. The Altgens photo was taken when the limo was high on the hill. It was nowhere near the point where he was shot in the throat. He may have been shot in the back already and probably was. But, definitely not the throat. 

There was a relatively long time in which JFK was shot only in the back and reacting to it. But, all of it was cut out of the Zapruder film. And they doctored the Altgens photo to create the illusion that it corresponds to Zapruder 255. The truth is that the Altgens photo does not correspond to ANY Zapruder frame.  It goes with the part of the film that was extracted and destroyed.