Science - ericsimages
Processed Solar spectrum from a full-spectrum modified Canon 40D, without (top) and with (bottom) an Astronomik Proplanet 742 IR filter.  These were recorded using a home-made holographic diffraction grating.

Processed Solar spectrum from a full-spectrum modified Canon 40D, without (top) and with (bottom) an Astronomik Proplanet 742 IR filter. These were recorded using a home-made holographic diffraction grating.