offset

With a traditional pipe bender, is there a minimum (parallel) offset that can be achieved over a distance of, say, 300mm? For example, could you achieve an offset of 10mm / 20mm / 30mm (and so on) over that distance? I know that benders are marked for 30° for lesser-offsets, but wonder if you...

Hello all, Hopefully this will be a simple one! I'm trying to fix this 68mm round guttering (see pic) but i'm a complete novice and rubbish with angles. Currently the downpipe is just loosely pushed into the gutter fitting above and resting on the stone below. I'm presuming it should be fixed...