3D camera vs real camera

[hanswillem]

Hi all,

I hope my questions are in the right forum,

I need to match a 3d camera in Cinema 4D with a real camera. It's for a shoot that involves motion control.
We setup a few shots in Cinema 4d and exported them as an FBX file for the motion control guys so they can use it to shoot a couple of actors that we can put in the Cinema 4D scene. After we sent it, the motion control guys told us that we need to change the film back of the 3d camera to match the real one they are going to use. And they said the real film back is 25.9mmX14.5mm. So my first question would be: am I right in thinking I need to change the film gate setting of the Cinema 4D camera to 25.9mm? I can only punch in one number, and I'm guessing it's the width, right? The help file doesn't seem to help me here.

Later the camera guys let us know that the camera they are using is a 35mm camera. That got me confused. Wouldn't that mean that the sensor size would have to 35mm? Can anybody shed some light on all of this?

Thanks in advance!

[yakuzowner]

hey,

I'm not really into the MotionControl Workflow but as far as I know 35mm is the diagonal length of a full filmframe on a film camera and refers to the film gate of your 3D camera... diagonal=sqrt(x²+y²)

but I dont guarantee that the filmback transfers 1:1 to the censorsize/filmframe

[hanswillem]

I did a bit of research, and asked some cameramen and some other people that know way more than I do about all this.
From what I can tell now, the 35mm refers to the width of a film strip in a movie camera including the sprockets and possibly soundtracks and the like. So the 35mm doesn't say much about the actual size of the image. The film gate of the camera masks out part of the filmstrip that is being lit. So it's the size of the film gate that I need. In the digital world the film gate translates to the chip size. And although labled as a 35mm camera, different camera's can have a variety of sensor sizes; different brands and types of camera's have different chip dimensions. So this means that I just have to look up the actual chip size of the camera they are going to use.

Oh and I did not read the manual close enough, because it does state that the filmgate of Cinema 4d refers to the width in mm.

[yakuzowner]

ah okay - good to know