camera object: meaning of aperture width?

[JIII]

well I don't know to much about photography per say. But aperture would mean hole or opening. So... this would lead me to think that it would be the camera lense or camera lense hole(don't know the technical word besides aperture) opening.

it means opening width really I think.

[doug reichert]

this would be equivalent to f-stop, wouldn't it? which would have a bearing on depth of field, and, coupled with shutter speed would determine the exposure, hence lightness or darkness of the image.

right?

[handige_harrie]

Originally posted by doug reichert
this would be equivalent to f-stop, wouldn't it? which would have a bearing on depth of field, and, coupled with shutter speed would determine the exposure, hence lightness or darkness of the image.

right?

As far as i know, it has nothing to do with dof, shutter speed or exposure.

Aperture width is basicly the diameter of the camera lens. Like JIII says.

Brammelo I tried doing composites, but I found it nearly impossible to get right. It felt like I needed more information on the cameralens (apperture width and focal length). Maybe you got some tips? Or anyone else?

[wesware]

Originally posted by doug reichert
this would be equivalent to f-stop, wouldn't it? which would have a bearing on depth of field, and, coupled with shutter speed would determine the exposure, hence lightness or darkness of the image.

right?

you are correct sir... it's the diameter that the iris (for lack of a better term) is set to, or the f-number

[doug reichert]

thank you. and as far as i can tell the "aperature width" setting in cinema has no relation to the aperature setting on a real camera, but rather serves to determine the field of view of the camera without having to change the focal length of the lens, which would cause either flat perspective, or a fich eye effect at either extreme.

correct?

[doug reichert]

uh... that's 'fish eye'

[AdamT]

There's another application of the word "aperture". SimonW explained this to me on Postforum a while back:

"aperture width refers to the size of the filmback (i.e. 35mm, 6x6, etc). to match a camera you need to know the focal length of the lens and the aperture width of the camera."

It would make more sense if the aperture setting in the camera object corresponded to aperture width rather than f-stop. Does it? I suspect so!

I think this is also referred to as film back aperture. For 35mm film it would be 35mm. For medium format, I believe it's 70mm, etc. The question is, why does the camera object default to 36 (instead of the most-common 35)?

[doug reichert]

i agree. especially since it has (apparently) no bearing on exposure or depth of field. but what the heck. one word is as good as the next, right?

[AdamT]

You can read some more info. about this in a Maya Live .pdf I found on the net. http://king1.ur.usu.edu/maya/win/live.pdf

[brammelo]

I do agree that aperture width is probably not the same as F-stop, because that would mean the C4D camera would have a standard F-stop of 36. A bit much, if I might say so. And besides: F-stop doesn't determine or change the "size" of the image, it merely regulates the amount of light and the focus depth of the image.

It might indeed be the filmback. Judging the Maya Live pdf, it most probably is. One wonders why Maxon called it aperture width. I'll pass it on as a possible manual correction.

Thanks a lot! :)

Kind regards,
BaRa

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