these three images were all taken using Ha, OIII and SII filters on various
regions of the Veil Nebula. I used the Ha for Red, the OIII for Green and
the SII for Blue.

There's some fascinating detail in these that is not normally seen in
standard RGB filtered images.

http://www.rdcrisp.darkhorizons.org/...in_ha_page.htm

http://www.rdcrisp.darkhorizons.org/pickering_page.htm

http://www.rdcrisp.darkhorizons.org/...egion_page.htm

comments welcome
Richard