why does the vray camera default to 36mm and not 35mm?

[loofer]

Simple question, i've always assumed i should leave this at it's deafult of 36mm film gate as the extra 1mm is added for a technical reason but should i be setting this to 35mm to match background shots for compositing?

[Dave_Wortley]

3dsmax defaults to an aperture width of 36mm, it's in the Render Scene Dialog, Guess it's just set like that for consistency.

[loofer]

Ok so it's a max thing then? i presume i should change it to 35mm if i'm matching a real photograph?

[vlado]

The frames for a photo camera are oriented horizontally along the length of the film; each frame is 36 mm x 24mm.

The frames for a movie camera are oriented vertically across the film; each frame is usually 22 x 16 mm.

Both types of cameras use the same physical film width, 35 mm.

Best regards,
Vlado

[loofer]

I see, i was getting confused between film gate and film size, thanks vlado

[Crayox13]

So if I match a photo taken with Canon 400D for which I know I have to multiply 1.6 to get the equivalent focal distance for 35mm, should I use film size or film gate? 35 or 36 to get the closest match?

I could also use different film gate since I now see it's the film width, initially I was not sure if it's diagonal of the film or width.

[Kyle_Grace]

Look up the CCD size of the Canon 400d (probably APS-C = 22.2mm).
http://en.wikipedia.org/wiki/File:SensorSizes.svg

Use this as the film gate and use the actual lens readout from the EXIF data from the photo. The 1.6 multiplication doesn't always work due to the variation in sensor sizes.

Hope that helps.

[stef.thomas]

If you are using the focal length multiplier to get the full-frame equivalent focal length for your camera, then you should use a 36mm film gate. Alternatively you can use the actual focal length given in the EXIF data and adjust the film gate to the width of your camera sensor.

This should clear up the 35mm/36mm confusion: http://en.wikipedia.org/wiki/135_film