Fast Acquisition Options

Fast Acquisition is useful for highly dynamic experiments in which you need to capture data quickly. It provides the greatest benefits when you are using the CoolSNAP camera.  

Use Fast Acquisition Options to specify the order in which wavelengths and Z sections are changed during a scan, when to open and close camera shutters, and the readout mode (the speed at which electrons are read on the CCD chip). Fast Acquisition should be selected only after you have manually acquired images of your specimen and adjusted exposure and other parameters until you are satisfied with the images.

To open the Fast Acquisition Options window, select Enable Fast Acquisition on the Experiment Designer. Then click Fast Acquisition Options.

Use

To...

Image Scan Sequence

Choose one of the following scan sequences:

 

  • Wavelength then Z switches filter positions before changing the Z position. Use this mode when wavelength alignment is critical. (This is the conventional DeltaVision scan sequence.)  

  • Z then Wavelength sequence collects an entire Z stack before switching filters and rescanning the specimen. This is faster because the filter wheels are moved only once for each wavelength during the Z scan. However, the different wavelengths may not be as well aligned as with Wavelength then Z scanning.

Open Shutter for Each

Select when the shutters should open and close during a scan.

 

  • For scans that use a full-frame CCD chip (e.g., the CH350 with a Kodak KAF1400), the shutter should always open and close for each Exposure. (Light should not be allowed to reach a full-frame CCD chip during readout of the image.)  

  • For scans that use an interline chip (e.g., the CoolSNAPHQ camera), the shutters can remain open during readout (These chips can electronically shutter the CCD chip very quickly. If the shutter is left open between exposures, the exposure time of the CCD chip is 1 divided by the frame rate.)

  • For scans that require more than one wavelength, the shutters should be opened and closed for each Exposure. (Leaving the shutters open allows light from one wavelength to contaminate the image of the next wavelength.)

  • For single wavelength Z scans, set the shutter to open for each Z Scan.

  • For time-lapse scans with only one Z section and one wavelength, the shutter may remain open for the Entire Scan. The shutter should be closed after each exposure unless the time-lapse duration is zero.

Camera Readout Mode

Choose the camera readout mode to match the experiment requirements. The implementation of the readout mode depends on the camera model and manufacturer. Not all cameras have noticeable differences between the modes.

 

  • Normal is the default camera configuration, which is usually the same as Slow/Careful.

  • Both of the Aggressive readouts attempt to move electrons more quickly off the CCD chip, which can cause electrons to be "spilled" into adjacent CCD wells. This is usually not a problem unless the CCD has collected a lot of light (i.e. electrons) and is near full-well capacity. In most cases, high-speed imaging does not allow sufficient time for collecting lots of photons, so the aggressive modes do not cause problems.

 

Related Topics

About Fast Acquisition