A little different version of the Helix Nebula

[ptc]

this is done using Ha, [OIII] and the 468nm Helium II line

Helium II is a very high energy line and is only found around the hottest of the central stars....

http://www.narrowbandimaging.com/ngc7293_ap180edt_ml4022_cshao3he2_p age.htm

shot with an AP180EDT f/9 and Microline ML4022 camera and the world's best emission line filters: Custom Scientific

Because I wanted to start and finish this in a single outing, I binned it 2x2

[renormalised]

Nice colours:):)

You don't get too much with the HeII filter, but then again there's not all that much of it around, even in PN's.

[leon]

Not keen on the color, but it certainly is nice and sharp, well done.

Leon

[ptc]

it is certainly not a commonly-seen palette in the astro-community. Turns out that the scientific community really likes that palette because it really does a good job of highlighting the high energy ionization regions: they sort of use the various spectral lines as a way of followingn the energy distributions driving the ionization.

For example, you may remember the Hubble shot of M57 using the same palette?

http://www.narrowbandimaging.com/m57_mk1sn2_hao3he2_luminance_schill ings_crisp_page.htm