This is currently a sticking point between me and my fellow co-producers (we take turns being director /DP on films). Currently, on the last production only one camera was used. In future productions they want to use two.

Great, but there is a problem.

I have a GH2 which I use for my films and they rely on a Sony HandyCam and they are concerned that the differences in the two cameras will be noticeable in the final product.

I'm on the opinion that if we do it right in shooting and in post this is not an issue, but they disagree.

This problem is compounded because they would like me to purchase a second camera (I'm assuming another Sony) and I want to go towards a Scarlet then it is released, but again.. Only one (they are expensive).

What are your thoughts on this dilemma?

The differences between Canon and Sony are significant enough to give you major headaches.

I would side with your colleagues...

The differences will be very noticeable.

Depending on what your film is about it may be a trait you can take advantage of to help tell the story. As an example a project I worked the story occurred in 2 time periods. We shot all the modern day stuff with a Sony Ex1r and the backstory portions were shot with a Canon 7d. This gave us very different looks between the two segments and it worked out pretty well.

You can see some of the differences in this video:
FOTHM Back Story Featurette (HD) - YouTube (http://www.youtube.com/watch?v=wWT-21xbMAI)

Hmmm.. This is a bit troubling.

Do you think I could get away using two different bodies of the same make of camera?

(Say a 7D and 5DM2)

?

Using a 7d and a 5d on the same production will be no problem. I've done it several times.

Similarly, Panasonics can cut together well (GH2, AF100, HVX, HPX#, HMC#, etc); Sonys cut together well (Z1/5/7, NX, EX), etc. Canon DSLR's kind of have their own look about them, different from the XF/XL/XH.

I will depend on how you plan to mix the footage. Cutting together in the same scene will look pretty noticable, but if for example you shoot all your night scenes on one camera and your daylight scenes on the other, you won't notice, because each scene is going to look different anyway.