Today's digital cameras are miracles, capable of capturing images in extremely low-light conditions. At the other end of the spectrum was the Kodachrome II slide film I used in my youth, with a whopping ISO rating of 25. This made capturing sharp images of moving trains in low-light conditions problematic.
Such was the case on this dull day in Aldene, NJ as the two car RDC "scoot" from Bayonne ducks under the Lehigh Valley overpass on its way to Cranford. Even at maximum aperture the shutter speed was too slow to keep the front end from blurring.