I flew on a Delta DC9-50 this afternoon ATL
and transited the airport with this thread in mind. It seems the epicenter of DL
D95 operations at ATL
is Concourse C. If you have a smartphone, firing up FlightAware will help a lot. You can check the arrivals/en route/scheduled departures to see what D95 operations are going on, and plan your trip through the airport accordingly. I was disorganized today and not really prepared, but I could have bagged several DC9 flights if I'd been on top of my game using this strategy. As I mentioned before, the way ATL
is laid out, you can get decent lighting virtually any time of day if you use the different concourses to your advantage. My flight today departed from the east side of Concourse C when the sun was still in the east, so a gate on Concourse D would have been the best choice to photograph my flight.
I did notice that the windows at the end of Concourse D seem to have been replaced by a new gate - so that angle may no longer be possible. Concourse C is the only other concourse with north-facing windows, but be aware that the angle of the windows there is skewed from the taxiway/runways so it's tough to avoid window reflections. I caught the Sktyteam 757 and of the three shots I took, only one appears to be reflectiion-free.