Speed ramps

Altering the camera speed also changes the film exposure time. In order to hold the film exposure constant when changing the camera speed, either the shutter angle of the mirror shutter or the aperture of the lens must be adjusted accordingly. The WRC-1 allows the camera speed to be changed while simultaneously retaining a constant exposure. Several different compensation methods can be selected. Example: the camera ramps up from 24 fps to 48 fps. Two compensation options are available:

Compensation

fps

Shutter Angle Aperture

Result

None

24

180

5.6

 

OK

 

48

180

5.6

1 T-stop under-exposed

Shutter Angle

24

90

5.6

 

OK

 

48

180

5.6

 

OK

Aperture

24

180

5.6

 

OK

 

48

180

4

 

OK

The required compensation type can be simply selected using the COMPENSATION rotary switch on the WRC-1.

The camera speed can either be adjusted using the handwheel, or it can be pre-set by programming a speed ramp, which is activated by pressing the RAMP button.

Note:

Adjusting the iris alters the depth of field.

 

Adjusting the shutter angle, on the other hand,

 

does not alter the depth of field. A small shutter

 

angle and a rapid camera movement, or fast-

 

moving objects, may result in stroboscopic effects.

 

Adjusting the shutter angle when using HMI

 

light may result in inconsistent film exposure.

Typical Applications

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