11
F
AST
C
AMERA
-USB
A
PPLICATION
C
ONTROLS
The
Figure 3
shows grouping of camera controls responsible for operation of each
camera mode.
Continuous Capture and Preview Mode
This is the main operating mode of the FastCamera. It is central to its operation and it has
the largest set of camera controls available for this mode. The FastCamera USB is forced
in the Continuous Capture and Preview mode by clicking the
Erase Camera
button. This
button starts every capture of the video sequence. It clears the camera memory, enables
new video capture to be written to camera memory, and starts the continuous video
capture in the circular memory buffer.
The visual indication of this mode is the live video display in the Video Preview area and a
checkmark appearing on the
Write
check box. It overwrites all video data you have
previously saved in the camera memory. The
Write-
box is checked when the camera is
writing to memory. During
Continuous Capture
mode the
Download
button is disabled.
(Getting images from memory while writing to memory is not supported).
Remember
:
every time the live video display stops after a trigger or a video download
operation just press the
'Erase Camera'
button. This will again start the capture and the
live preview display albeit it will wipe out any image data you have recorded.
The
Full-
Check box will be marked first time when the camera memory has been filled by
the incoming video data completely and image data collected earlier is being over-written
by new image data. The
Full
mark stays on until the camera memory is erased again.
You can not use the camera memory to store multiple recordings. The
Erase Camera
button starts recording always at the beginning of the camera memory (address zero).
During the video capture the camera memory is treated as a ‘circular-buffer’. This means
that writing of images to memory begins at the start of memory and continues to the end of
memory and then wraps around to the beginning of memory again. Given enough time
older image data is overwritten with new image data. The number of images that the
camera can hold in memory can be computed from the following: a 1GB memory can hold
508, 1280x1024 images. If you set the frame rate to 500 frames per second this is just
about one second of video. (That is as fast as the camera can go at that frame size.) If you
take the ratio of the image size that has been set to the size of the full image and multiply
by 508 you can determine how many smaller images will fit. (508 *
1280*1024/(width*height) = number you can fit). If you have less than 1Gbyte in your
camera, scale the number again. When you download the images you can get the actual
number that fit.