I was taking photos for a friend. I find that when I zoom in, I get a underexposed picture. But when I use a shorter focal length, the picture is brighter.
Both photos were taken at ISO400, 1/40s, f5.6. The only difference is degree of zoom.
The darker picture is taken using a focal length of 135mm (202mm for 35mm equiv), the brighter is at 85mm (127mm for 35mm equiv).
Am I missing anything? Thanks.