"Center Of Interest" parameter affects exposure of PhysicalCamera.

[flat]

An "Center Of Interest" parameter affects exposure of PhysicalCamera.　

If "Center Of Interest" parameter is changed, Focal length inside Physical camera can be seen changed.
(Specify FOV is set to "from Maya Camera".)

Is it the correct behavior?
It does not occur with the 3dsMax versions.



AAAA.zip

[vlado]

It is correct and it does occur in 3ds Max as well, but the effect is dependent on the scene units (scenes in 3ds Max are much larger by default). We did some practical experiments here and observed the same behavior with an actual camera.

Best regards,
Vlado

[flat]

Ok. Thanks.
I check up more.

[Komposer]

For me, its sometimes a prob too, and I wish the option to switch this effect off!
Because when I work on a smaller object, a watch as example, its not pos
to make macro-cam-positions without scaling the whole scene, or animate the ISO towords.

The best way is, to model in real units and in cm.
So u can be shure, that everything over 10 units is without or nearly without the "darken effect"...
But in case of macro, lower than 10 units, u can´t...

Another strange thing for me is, that there is a diff, between "Specify focos" on or off.
No matter if u need it or not!
So the best thing is, to switch it on when u start a scene and set it to 100 or so..

Jörg

[vlado]

You can always turn off the physical camera exposure...

Best regards,
Vlado

[vlado]

In case you are interested, here are some of the experiments that we did.

We put a camera in front of a white board with a rectangle drawn on it, and locked down the exposure of the camera. Then we focused the camera at the white board and took an image, then we focused at finity and took another image.

The camera focused at the white board:


The camera focused at inifnity:


An outside view of the camera setup when focused at the white board:


An outside view of the camera focused at infinity:


You can clearly see two effects:

= first, the field of view changes quite a bit
= second, the resulting brightness of the image changes visibly.

The V-Ray physical camera simulates both of these (d)effects.

Best regards,
Vlado

[ebee]

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