To get the ‘texture’ of the terrain and shape shadows, low angle lighting is the go. Sun angle too high and the image can be ‘washed out’ and shape less distinctive/ defineable
With mapping photography in Oz, imagery could only be gathered in summer between 7.30 til 10.30 and 2.30 til 5.30 to avoid shadow point sun flare. In winter with the sun way north you could go all the (shorter) day as that effect never occurred. Further south one had a very short working/ imaging day..not enough sun angle.
These things would be ignored in war time recon of course.. grab some pics while the weather/ clear skies allows
Same with obligue views the right sun angle on the target from the right perspective can make a great difference in the quality of the photography.
I dips me lid to those guys who flew alone, unarmed,cold and high on long missions over enemy territory.
Or dashed about at low level, very much in harms way.
The last aircraft shot down over Oz was a Mitsubishi “Dinah”, that lovely sleek and fast Japanese recon twin.
Their pictures and the crew never made it home. Cosford has the last of type.