• Created by Unknown User (g-shepherd@northwestern.edu), last modified on Mar 15, 2010

Overview

A program for controlling Q-Imaging CCD cameras. The QCam program can be launched as part of Ephus (by including it in the startup file). Alternatively it can run as a standalone program; in this case, launch it from the command line by running 'startQCam'.

File > Open

n/a

qcammex (menu)

Provides a number of options and utilities, and version information. Open Camera opens the camera for use by qcam. Release Driver releases the driver for use by other software programs. Reset resets the camera settings. The options below the divider, Print Camera Info and Print State, cause camera settings to be printed to the Matlab command window. The last option, aboutQcammex, provides version information.

Acquisition Panel

Start

Launch image acquisition. Data will be saved to disk if a file is specified and 'Record to disk' is checked. If not, images are acquired continuously without saving.

External

Sets triggering to external.

Preview

Image in preview mode; no data saved.

Exposure

Set the exposure duration, in msec.

Temporal Averaging

Specify the number of raw frames over which to average. The default is 1; i.e., no averaging.

Spatial Bin Factor

Specify the spatial binning.

Snapshot

Takes a snapshot, using the current settings.

Online Display Panel

Display

Controls whether the image is displayed.

Update Rate

Sets the update rate.

Look-Up Table

Several options are provided for setting the LUT.

White, Black

Specify the upper (white) and lower (black) levels individually.

Full

Set the LUT to span the data range, from the minimum to maximum values.

stdev

Set the LUT to +/- 2 s.d. of the mean of the pixel values.

Histogram

Displays a snapshot histogram plot of the pixel values.

Disk Logging Panel

File window, Browse button

Specify the image data file.

Record to disk

Turn on (check) or off (uncheck) data saving.

Frames to acquire, Frames per file

Specify the number of frames to acquire, and how many frames per file.

Format

Specify the format. For some cameras only 1 option is available.

Naming Scheme

Options are 'Manual' or 'XSG'.

Header Data

Scale, X and Y

Provide the scale for the horizontal (X) and vertical (Y) dimensions of the cameras full field of view, in micrometers.

Timing

A convenient way to make a note of the timing of a stimulus. Entirely optional.

Comment

Add a comment.

ROI Panel

Zoom, Full View, Offset, Extent

After selecting 'Zoom', click and drag on the video image to define a zoomed region of interest. Selecting 'Full View' restores the image to full. The 'Offset' and 'Extent'
windows show the current values for the X and Y offsets, and width and height.

EXTERNAL TRIGGERING

An external triggering board for qimaging cameras is required. The board should be connected to the camera, and receive input from an analog output channel on the DAQ board.

Set parameters in qcam. Then, hit 'External'.

Make a pulse for the camera in pulseEditor. TTL pulse (5 V, 1 ms)  from the DAQ board triggers the exposure of the camera. A TTL pulse triggers the acquisition of a single frame. If it is necessary to get multiple frames, train of TTL pulses is required (i.e., one pulse per frame). In such a case, 'Exposure' time in qcam has to be sufficiently shorter than the intervals of TTL pulse. Otherwise, TTL pulses are ignored.

The TTL signal goes to the 'External input' BNC. However, the NI board may not be able to drive the input without removing the "R4" resistor (located next to the BNC).

NOTES

(1) Preview mode is compatible with the concurrent use of other Ephus programs, such as the scope.

(2) For Q-Imaging cameras such as the R2000DC -- if control over the temperature setting is required (for example, turning off the cooling, to avoid condensation), the following should work:

  • Obtain an updated version of the MEX-file qcammex.mexw32 from this site.
  • After the camera is configured, run: 
    qcammex('setRegulatedCoolingTemp', T);%T is the desired temperature, in degrees C.
    The command can be run anywhere after the camera is opened, you may even run it directly from the command-line. If you want to add it to the M-file, it is recommended to put it in the updateVidSettings function.
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