no father ted jokes!! if my lens is further away from the subject does this give me a larger depth of field than close up. so if my initial set up is close up at 100mm then i go further back and zoom in at 400mm will the 400mm give a larger depth of field or does the zooming in counter it
The easiest way to asses DOF efects is to download one of the photo apps that do all the calculations for you onto your 'phone. I use Hyperfocal Pro and DOF Calculator - they are invaluable!
All things being equal depth of field will decrease as you zoom in, and on a separate note depth of field will increase as you increase the distance between you and the subject. So it depends on how far you step back to counter the zooming in.