Lens Creep wrote:
yes, for 1.4x TC, you lose one stop of light. I generally make that up by increasing ISO by 2/3rds stop and opening aperture by 1/3 stop when mounting the TC. Shutter stays the same, so fast moving subjects will still render same motion as without TC.
But, how about the speed and accuracy of your AF ?? And, upping ISO means your IQ is going down .....
.