Hello everyone I have a Canon EOS50D. With 100-400 stabilized, wide angle. I have to go according to photos to tornado at night. I've never done, I recommended to use shutter priority, TV (1/800). O aperture priority, AV? If you do that diaphragm? What do you recommend what is best, time and also raise the ISO to the maximum extent, EOS50D. aspect you nes hello