Tweet
At our studio, some productions are done with the Maya standard camera, and some are done with a V-Ray Physical Camera. We've noticed that the depth of field-effect do not match up, when we expect the values to be "equal".
In the V-Ray for Maya documentation, the "aperture" value within camera overrides (for Maya standard cameras) is said to be the size of the aperture in world units. World units are cm per default in Maya. So a value of 1.25, for example, means that the aperture is 1.25 cm. Is this correct?
When we tried to match this value with a Physical camera, however, they did not match. To get an aperture size of 1.25 cm, I set up a camera with a focal length of 50 mm (5 cm) and an F-number of 4. This should mean the aperture size is 1.25 cm (5/4). Why is the effect not the same? Have we misunderstood something?
I've attached an image to give a visual example of the issue. I created a camera, set the focal length to 50 mm, film gate size to 36 x 24 mm and the focus distance was 10 cm. Then I duplicated the camera, and made one copy a V-Ray Physical Camera with the F-number set to 4. The Aperture value in the Camera override for the Standard camera was set to 1.25. The two renders have been cropped along the white line to show the difference.
It is quite obvious that the Standard camera gives a stronger DoF-effect, i.e. less is in focus.
Maya version is 2019.2
V-Ray version is v 4.30.03
In the V-Ray for Maya documentation, the "aperture" value within camera overrides (for Maya standard cameras) is said to be the size of the aperture in world units. World units are cm per default in Maya. So a value of 1.25, for example, means that the aperture is 1.25 cm. Is this correct?
When we tried to match this value with a Physical camera, however, they did not match. To get an aperture size of 1.25 cm, I set up a camera with a focal length of 50 mm (5 cm) and an F-number of 4. This should mean the aperture size is 1.25 cm (5/4). Why is the effect not the same? Have we misunderstood something?
I've attached an image to give a visual example of the issue. I created a camera, set the focal length to 50 mm, film gate size to 36 x 24 mm and the focus distance was 10 cm. Then I duplicated the camera, and made one copy a V-Ray Physical Camera with the F-number set to 4. The Aperture value in the Camera override for the Standard camera was set to 1.25. The two renders have been cropped along the white line to show the difference.
It is quite obvious that the Standard camera gives a stronger DoF-effect, i.e. less is in focus.
Maya version is 2019.2
V-Ray version is v 4.30.03
Comment