Recently I used the VRay lens analysis tool on a photo I took using a Canon 5D MkII with a Sigma 50mm Prime lens. Weirdly, after analysing fine, it put the focal length as 47.233. Any ideas why that might be? All the tech specs online say that that the lens is 50mm bang on.
Then in Max, when I set the VRay camera to 50mm using a film gate of 36mm I'm not getting a perfect result. If I drop the focal length to around 48mm it's a lot better. I really need to get this spot on for the work that I do so any help greatly appreciated.
