T4i Av mode issue
I agree. In av mode with a long exposure the camera is trying to capture the ambient light at iso 400 in auto iso mode. Iso 400 is probably chosen by the camera because of the low noise levels.
you can certainly set the iso speed yourself. For example you can set it to 1600; the shutter speed should increase albeit more noise will show in the snap.
|Blue and yellow in water by fireplace33|
from Ink and water
|Kylmä joki kopio by Kaappo|
from Shutter speed 1/25 or slower
|WR_2.8_13 copy copy by photoprof|