Buyers Guide: Featured Product

Continuous Reflective Interface Sample Placement Autofocus

The CRISP system is designed to maintain focuses over time i.e. compensate for thermal & other factors that may cause the sample to drift out of focus over time. It also can be used to maintain a given focal point while scanning the sample in XY.  The system provides for a very high level of focus stability, allowing a specimen to remain accurately focused for hours at a time with drift of less than 5% of the DOF of the objective. The unit offers many features including:

  • Uses LED’s as the illumination source so any wavelength from 640 to 1050 nm can be used, with 780nm being the most common
  • Mounts onto any microscope’s standard C-mount port
  • Maintains ideal focus for days
  • Works with most normal microscope objectives
  • Low noise electronics allows locking to glass/water interfaces
  • Integrates with ASI Piezo-Z or motorized focus stages
  • Simple post-lock fine adjustment of focus
  • Automated control

Theory of Operation

The CRISP system projects the image of a mask illuminated with an IR LED into the sample plane. Only one half of the objective pupil is illuminated. This means that the point spread function of the objective is highly skewed, so that the reflected image of the mask will move laterally as focus is changed. CRISP detects this lateral motion of the LED image to obtain a focus error that is used to close the focus positioning loop.

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For details on products, please visit: CRISP

Applied Scientific Instrumentation (ASI)

Manufacturer of hardware for microscope automation and fluorescence microscopy including extremely precise closed-loop DC servomotor stages and focus controllers for ultra-precise XY axis positioning and Z-axis focusing, complete video microscope systems, high-speed monochromators, high-speed filter wheels and shuttering devices, microinjectors and micromanipulators, and a wide range of other devices for micropositioning and illumination control. ASI also offers video cameras, frame grabbers, and imaging and photometric systems.

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