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Revision as of 11:35, 25 February 2014 by Kdb (Talk | contribs)

Complete description can be found at BIG


pgFocus is an open source and open hardware, for noncommercial use, focus stabilization device developed by Karl Bellvé at the Biomedical Imaging Group (Progam in Molecular Medicine, University of Massachusetts Medical School).

The pg in pgFocus is short for "Pretty Good". pgFocus isn't "Perfect", or "Definite" but it is pretty good!

pgFocus monitors focus changes through the positional changes of a reflected laser beam. A significant feature of pgFocus is it acts as a "man-in-the-middle." It is designed to pass through faster high fidelity signals meant for a piezo Z controller while adding a slower focus control signal. This happens in the analog realm, which avoids sampling artifacts introduced by digitizing the original signal. This design also reduces the cost of pgFocus.


Serial Settings

  • 57600 BAUD
  • Handshaking off
  • Parity None
  • Stop Bits 1

pgFocus Plugin

Real Time Panel

The pgFocus plugin graphs incoming data from the pgFocus hardware.

PgFocus Realtime.png

Top graph shows the current focus offset.

Second from top graph is the Standard Deviation of the offset over time, in nM.

The second from the bottom graph shows the voltage output, in nM, of the on-board Digital to Analog Converter.

The bottom graph shows the voltage input, in nM, as measured by the on board Analog to Digital Converter.

The update frequency can be changed in the settings panel.

Light Profile Panel

The light profile graph can be used to center the reflected laser beam onto pgFocus' sensor.

PgFovus Lightprofile.png

The refresh rate can be adjusted in the settings panel.

Calibration Panel

PgFocus Calibration.png

Calibration should be performed after setting up pgFocus, and after any changes. It lets pgFocus know how far to move the objective to maintain focus.

Settings Panel

PgFocus Settings.png

Most of the important parameters can be changed on this panel. Additional parameters can be modified or viewed in the Device/Property Browser window for pgFocus.

Device/Property Browser

PgFocus DeviceAdapter.png
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