PRISM trick: magnifying glass

There is a very nice feature in PRISM which magnifies part of your image. This magnifying glass is very seful to check on the guided star and how it "fits" within the fiber tip (fiber fed echelle spectrograph) or a slit of a slit-spectrograph.

The consign (lock position) can be adjusted at sub-pixel value even when autoguiding is ON - a great functionnality for astronomical spectroscopical acquisition!