Instruction manual

158
Operation
Note: A ”positive” ramp is a frame rate change to a
higher fps value. Example: 10 to 50 fps.
A ”negative” ramp is a change to a smaller fps
value. Example: 50 to 10 fps.
The approximate minimum ramp time can also be derived
from the nomogram. To calculate the minimum ramp time,
connect the two camera frame rates with a straight line
and read the time at the intersection of that line and the
time scale.
For example, if ramping from 12 to 48 fps, the ramp
should not be shorter than 0.75 seconds.
To shorten the ramp duration when a large fps range is
covered, the ramp can be broken up into separate smaller
ramps. These can be run consecutively.
For example, if ramping from 4 to 96 fps, 6 seconds
would be the minimum time. But if ramping:
• from 4 to 16 fps, the minimum ramp time is 0.75
seconds, and if then ramping
• from 16 to 96 fps, the minimum ramp time is 1.25
seconds.
Combined, the new minimum time is only 2 seconds.
Consecutive frame rate ramps can be created with an
external camera controller like the LCC.
Changing camera frame rate manually with VSU:
Multiply derived minimum ramp time by 3 to be sure that
possible uneven speed change of the ramp is not critical.