Originally posted by stillshot2 I bet the pop up flash indicator is flashing in the viewfinder asking you to raise the flash before it can take the picture in auto mode. The best thing to do is stay away from auto mode and learn the relationships between aperture, shutter speed, and iso and then start using other modes.
+1
Yes, in the green AUTO mode for most DSLRs the shutter will not fire in lowlight, my Pentax K50, Canon 50D, and Canon Rebels behave the same way. Best to go manual control which is one of the great features of owning a DSLR. Of course an option some people see it as too much work, such as my own wife - iPad is her camera...