Photon Focus DR1-D1312(IE)-G2, User Manual

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4 Functionality
E x p o s u r e t i m e
F r a m e r a t e
( f p s )
S i m u l t a n e o u s
r e a d o u t m o d e
S e q u e n t i a l
r e a d o u t m o d e
f p s = 1 / r e a d o u t t i m e
f p s = 1 / e x p o s u r e t i m e
f p s = 1 / ( r e a d o u t t i m e + e x p o s u r e t i m e )
e x p o s u r e t i m e < r e a d o u t t i m e e x p o s u r e t i m e > r e a d o u t t i m e
e x p o s u r e t i m e = r e a d o u t t i m e
Figure 4.1: Frame rate in sequential readout mode and simultaneous readout mode
When changing readout mode from sequential to simultaneous readout mode
or vice versa, new settings of the BlackLevelOffset and of the image correction
are required.
Sequential readout
By default the camera continuously delivers images as fast as possible ("Free-running mode")
in the sequential readout mode. Exposure time of the next image can only start if the readout
time of the current image is finished.
e x p o s u r e r e a d o u t
e x p o s u r e r e a d o u t
Figure 4.2: Timing in free-running sequential readout mode
When the acquisition of an image needs to be synchronised to an external event, an external
trigger can be used (refer to Section 4.4). In this mode, the camera is idle until it gets a signal
to capture an image.
e x p o s u r e r e a d o u t
i d l e e x p o s u r e
e x t e r n a l t r i g g e r
Figure 4.3: Timing in triggered sequential readout mode
Simultaneous readout (interleave exposure)
To achieve highest possible frame rates, the camera must be set to "Free-running mode" with
simultaneous readout. The camera continuously delivers images as fast as possible. Exposure
time of the next image can start during the readout time of the current image.
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