I have been working on the 416 for about 5 weeks now, its a great camera it just has one major problem the magazines are badly designed !. This is not just a bad work man blaming her tools.
When taking rushes out you have to be really carefull, there is no collapsible core like the SR3 there is a spindle with 3 ball bearings sticking out and the plastic core is fitted onto that and this is where the problem lies the tension cannot be ajusted on these ball bearings so when taking out the rushes you lift the film and the core will often not come with it, the film cones if you lucky you can get your fingers under the core as the rest of the roll dishes up if not you have a roll of film with the central 20 ft hanging out and its impossible to coil it up tightly enough.
One solution is this with a little stick or that red straw from a wd40 can put a little silicone one each ball bearing and rub it around and pres in the ball so that the silicone gets underneath then the core is easier to remove.
Also the doors on the magazine can be gappy ! so if you not happy send them back to the rental company and they will bend the catches to make the doors tighter ! Hope this helps someone.
