0.1  Brief Description of the Instrument

NSFCAM is a 1-5 micron imager with a 256x256 InSb detector.  Simultaneous 
optical imaging is possible via an optical port.  Three different 
magnifications can be selected by rotating different cold lens 
assemblies into the beam.  These give plate scales of 0.3S/pixel, 
0.15S/pixel and 0.06S/pixel, with corresponding fields of view of 
76.8S, 37.9S and 14.1S respectively.  Images can be obtained through 
a variety of broad- and narrow-band filters, and low-resolution 
spectroscopy can also be carried out using the circular variable 
filters (CVFs) or grisms.  Polarizing waveplates or grids can be 
inserted into the beam.   Two cold coronograph masks are also available.

Images are recorded onto a Sun workstation in FITS format.  These are 
taken in basic stare mode using the main (object) and offset (sky) 
telescope beam positions; software is available to shift-and-add series 
of images together to study fine image structure.  It is also possible 
to take frames rapidly in movie mode, storing them directly to the 
instrument computer and saving overheads in time-critical observations.

A FITS viewer is run at the telescope which provides basic image 
manipulation utilities.  Both the camera and the image viewer can given 
series of commands using simple ascii macro files.  These commands can 
include offsetting the telescope to make image mosaics.

In the near future we hope to have the IRTF tip-tilt system working in 
conjunction with NSFCAM for active image control.  Meanwhile an off-axis 
visible camera is available for guiding on nearby  (relatively bright) stars.