Film gate / focal length

[0livier]

Hello,

I am trying to exactly measure the 'field of view' seen by a VrayCamera.
If the Film gate is set to 36mm and the Focal length to 24mm, then an object situated 1.2 m in front of the camera will have to be 1.8m wide to exactly fit in the frame (in the screen). I hope i am clear. I have attached a screen shot of the drawing.
But it looks like it is not exactly working like this, there is a tiny angle difference, as you see on the screenshot. My calculation must be wrong.
Any idea ?

Thanks,
0livier

[vlado]

It depends on where the camera is focused; if you make it focused at a point very far away, you should get a better match.

Best regards,
Vlado

[0livier]

Hello Vlado,

That's exactly this ! thanks a lot.

The focus distance is indeed changing a little bit the Field of view (few degrees)... i don't understand for which reason... but Thanks !

Cheers
0livier