4.Mrz
2013

Quicktip: A real world camera in m4d/iray

Know-How
Quicktip: A real world camera in m4d/iray

Three different looks done directly in C4D with m4d’s iray.

Admittedly we’re no big fans of adjusting and color correcting our renderings directly in Cinema4D. That’s what we usually do in After Effects with the help of an armada of plugins and tricks.

However with R14’s post effects and more so with m4d’s camera tag it is getting easier to achieve a look that’s more closely to a final image while rendering straight in C4D. Useful to judge if your rendering is going in the right direction.

Here’s some tricks I found handy:

M4d‘ camera tag gives you the very powerful mia photographic exposure mode, which allows you to adjust your camera using real world units:

cm2 factor: this is the first setting I adjust. For the mia physical sky i usually set it to 10000. It allows you to adjust the overall energy (light intensity) the camera receives. In laymans terms: makes your overall image brighter or darker without touching anything else.

ISO: Camera’s sensitivity to light. In real world cameras this usually is in the range of 50 – 12800. I usually start with it set to 100. Higher values yield a brighter image.

f-Number: Defines how closed (or open) the camera lens‘ aperture is. Lower values mean more light coming into the camera. Real world values are usually in the 1 – 32 range. I go with 2.8 as a starting point.

Shutter speed: defines how long the cameras „sensor“ is exposed to light. Unit is 1/s meaning that lower values result in longer exposure times. I usually set it to 100 ( resulting in an exposure of 1/100th of a second).

White balance: Different light sources have different colors. An incandescent bulb has a yellowish tone, the afternoon sun is more blueish. The amount of blue in a light source is defined via its color temperature. It’s measured in degrees kelvin and the afternoon sun (generally agreed to as being „daylight“) has a light temperature of 6500k. If you to take pictures in daylight and have your camera still set to incandescent, your resulting pictures are gonna look blue. Funnily m4d doesn’t allow to set white balance via color temperature but with a color selector. Give it a try for some retro looking renders with orange-brown tint. Or use the attached camera setup to adjust white balance using a kelvin slider.

Vignette: A lens usually is brightest at its center with some darkening occurring at the corners. This is what vignetting does. I use a value of 7 which is already pretty pronounced.

Crush Blacks: Real world cameras are not as powerful as our C4D camera in terms of dynamic range. Parts of an image that are too dark just become black. That’s what crush blacks simulates. I usually set it somewhere between 0.5 and 1.

Burn Highlights: On the contrary, parts of the image that are too bright just appear plain white in a real camera. That’s what you adjust with burn highlights. I usually set it to the same value as crush blacks.

Gamma: Here’s where the fun begins. Traditional film doesn’t react linearly to light, meaning that a part of the image twice as bright as another part does not necessarily result in that part being twice as bright on film. Gamma adjusts the camera’s response curve. Try values around 1.4 – 1.8 for a contrasty film look.

For the guys & girls amongst you that are more used to working with photographic cameras I’ve attached a small setup where you can choose your settings from standard real world values:

The standard mia_exposure camera tag: Quicktip: A real world camera in m4d/iray


… with a littel help from XPresso… Quicktip: A real world camera in m4d/iray


Gets the ability to adjust white balance via °k (Kelvins): Quicktip: A real world camera in m4d/iray


As well as some predefined real world values to choose from: Quicktip: A real world camera in m4d/iray


Download .c4d file