I recently bought a C100 and and Tamron 24-75 zoom. I am used to shooting with Rokinon primes which are great for low light such as weddings. I am hesitant to use my primes on my C100 because I am afraid of dust. I know that sounds crazy but you can't just take it to your local camera store for a sensor cleaning. You actually have to send it into Canon which will cost around $230. For those of you who own a C100 do you see much difference when using a zoom or primes? Is it worth risking the possible dust that may end up on the sensor? When I change my lenses I do point the camera down and have the lens ready to switch. I am pretty fast, but lately I have found dust on my 6ds and do not want the same for the C100.

There's a piece of glass over the sensor and its easy to clean. Nothing to worry about. Both mine are fine after 3 years of abuse. Dust in the primes would be much more of an issue. Stop worrying about the gear and shoot with abandon! :)

@ Nate,
Can you use a lens blower to clean the glass that is infront the of sensor? Is it easier to clean than a dslr sensor? Thanks in advance.

Yes of course. There really aren't any nooks and crannies. It's completely sealed and covered with the glass. Be delicate, but I've used lens wipes, q-tips, paper towels and t-shirts. Obviously some options are better than others but seriously, I wouldnt worry at all. There's no mirror like a DSLR.

Some people say you definitely shouldn't touch it - they may very well be right as there's probably some sort of coating on it. But I've cleaned it off on several occasions and haven't seen any issues whatsoever with my images. YMMV.

Jeez you want to film with the A7s - full frame completely exposed every lens change (half a dozen times each wedding) and it's a dust magnet!!!