V-Ray Physical Camera focal length affected by C4D Project Scale

[JeremyLondonMDL]

I've encountered an issue where renders from the V-Ray Physical Camera seem to be zoomed in when the Cinema 4D Project Scale is set to smaller units such as inches, centimeters and millimeters. The smaller the Project Scale units, the more the camera seems to zoom in when the scene is rendered. With the Project Scale set to millimeters it's very obvious. When it's set to inches it's only subtle. When set to feet, meters, kilometres it appears to render correctly.

See attached screenshots showing this effect in the rendered viewport. The same thing occurs when the scene is rendered to the picture viewer.

Has anyone else experienced this, and is there a setting I can adjust to prevent it?

Thanks

[JeremyLondonMDL]

... Here are some images of the more subtle effect when the Project Scale is set to centimeters and inches

[aleksandar.kasabov]

Hello JeremyLondonMDL,

Please note that this behavior is expected as the setting for the focal length takes into account the system units configuration to produce the correct result. This applies to the Film Gate setting as well. You can find more information about the V-Ray Physical Camera and its settings here.

[JeremyLondonMDL]

Thanks aleksandar.kasabov,

Could you please explain a little more what this means, and how it works? For example, should I be using a multiplier on the Focal Length and Film Gate values if my Project Scale is Centimetres or Millimetres?

Regards

[aleksandar.kasabov]

Hello JeremyLondonMDL,

The focal length and the film gate parameters are specified in millimeters. This is why if you change the scale of the project, the values (in millimeters) won't be the same, relative to the scene scale. If you want to switch the project scale, for example from centimeters to inches, you will need to multiply the current values of the focal length and the film gate parameters by 2.54 (as 1 inch= 2.54 cm). I hope that this makes sense and it is of help.