IDAS HEUIB-II filter bandpass plot The IDAS HEUIB-II (H-alpha Enhanced UV IR Blocking) filter is designed for enhanced spectrum DSLR's and one-shot color CCD astronomical cameras.

Besides removing the IR and UV ends of the spectrum which are often out of focus in refractive optics, it isolates the common H-alpha line relative to the surrounding extreme red end of the spectrum, making it easy to bring out the faint H-alpha emission nebulosity of astronomical photos, yet retain the background color balance of broadband photos.

IDAS HEUIB-II UV/IR blocking filter

Some filter comparison shots as well as customer results using the HEUIB-II filter can be seen here:
Available in 52mm and 48mm sizes mounted in standard camera filter rings, 37mm size mounted for the Canon MFA, and unmounted in 36mm and 49mm sizes. The filter is also available as a Nikon front filter.

Some comparison shots taken with the enhanced Canon 6DH (standard Canon UV/IR blocking filter vs. HEUIB-II filter) show a clear difference both in background sky color balance and contrast of H-alpha nebulosity in the extremely faint object IC1396. Note the good background color balance as shown in the histograms of the individual color channels of the HEUIB-II filtered image. Click on images to view enlargements.
Canon 6DH / std UV/IR blocking filter Canon 6DH / IDAS HEUIB-II filter
Canon 6DH with standard Canon UV/IR blocking filter Canon 6DH with IDAS HEUIB-II filter

Milky Way and H-alpha regions -- Canon 6DH + IDAS HEUIB-II filter At left, a wide shot of the Milky Way clearly shows enhanced contrast of H-alpha regions. Click on the photo for enlargement.

Daylight example shot with HEUIB-II filter on enhanced-spectrum DSLR  
The HEUIB-II filter also returns normal daylight color balance to spectrum-enhanced cameras as can be seen in this photo at right taken with normal DSLR auto-white-balance (AWB) enabled.