Vray physical camera focal length question

[hermit.crab]

Based on what I've found out:

When using a Physical Camera, the are three ways to set the FOV:
1. From Camera - takes the focal length from the Maya attribute and calculates based on it
2. Specify - you set the FOV directly in the V-Ray settings
3. Off - you set the Focal Length directly in the V-Ray settings

When touching either of these, the others with be updated. If you're wondering which FOV is more "correct", I suggest you use the V-Ray one. V-Ray internally uses more parameters than Maya provides to calculate its FOV. Simultaniously, that's how V-Ray manages to produce an image, identical to another renderer. For more specifics, the devs must look at the code - do you need the formulas?

[seandunderdale]

Hi Aleksandar. Thanks for taking the time to look into it. I think Ive managed to get very close to creating a a vray physical cam result to a maya camera using a specific real world camera aperture and lens. I think the key thing I was missing was Vray locks the Maya camera aperture to 25.4mm x 25.4mm, but I needed to set the Vray film gate to whatever real world camera I was using...so, for example with a GFX100 Id need to set the Vray film gate to 43.8mm. This seems to get very very close to the camera Maya creates using the same camera aperture and lens data....its not identical...but as you say, maybe the Vray one is actually more accurate...that would be nice as I can get very tight camera matches using Maya method, so if Vray is even better, then we are on to a winner.