The Sutter Instrument Lambda SC is a full-featured microprocessor-controlled driver for SmartShutter stepper-motor optical shutters. It controls blade trajectory with precision — offering both fast mode for maximum speed and soft mode for minimal vibration — and opens the shutter in 8 ms from a TTL trigger. The controller supports stand-alone operation, computer control via USB or RS-232 serial, and integration with other Lambda series instruments including filter wheels and light sources.

Neutral Density Mode and Variable Aperture

A defining feature of the Lambda SC is its 144-step neutral density mode. The shutter blade can be positioned at any of 144 discrete steps between fully closed and fully open, creating a variable aperture without an external ND filter wheel. This is particularly valuable in fluorescence imaging where precise excitation light control reduces photobleaching and phototoxicity while maintaining sufficient signal-to-noise ratio.

Operating Modes and Timing

The Lambda SC supports multiple operating modes accessible from the front panel or via computer control. Free-running mode cycles the shutter open and closed with user-defined delay and exposure intervals up to 5 hours at millisecond resolution. Trigger mode accepts TTL signals configurable for high, low, or edge-triggered activation. A programmable delayed sync output coordinates external devices — cameras, acquisition boards, or second shutters — with the exposure sequence. The controller can run continuously or loop for a specified number of cycles.

Shutter Compatibility

The Lambda SC works with the full range of Sutter SmartShutter apertures: 12.5 mm, 25 mm (stand-alone and filter wheel versions), 35 mm, and 50 mm. The 25 mm and 35 mm shutters achieve the 8 ms open time and sustain 40 Hz and 20 Hz continuous operation respectively. All SmartShutter variants are life tested to 100 million cycles, ensuring reliability in high-throughput imaging workflows.

Technical Specifications