That's a great grab of the Helix Rich, looks really etheral and mystical to me with good fullness and nice composition too, very well done.
Not sure on the relevance or indeed accuracy of Jase's comparison though? I think the little 6" Starfire holds its own rather well actually
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Those faint galaxies visible in your Lum are never going to show up in Halpha nor are many of the stars that help provide the depth. Since it was narrow band (Ha) and could have thus done with significantly more exposure at F7.5, there is more detail evident in the main nebula and particularly the inner tendrils in this 2Hr's of Halpha I did last year, even with only 6" of aperture
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http://upload.pbase.com/strongmanmik...86072/original
The "depth " is however more obvious in your Lum than my Halpha due to the extra stars and those galaxies and also the less defined structure in the bright regions giving it a billowing look. Lum lets in lots more energy too so signal to noise is much greater, but the fine structural detail is still greater in the Halpha.
A compilation of both is the way to go IMO and I have done this already with your Lum data and my Halpha data and the result is pretty good IMO - best of both worlds now, (havng your slightly larger FOV would have been better though)
Take a look
http://www.pbase.com/strongmanmike20...55309/original
I have also just for fun then added my rather "in ya face" full HaRGB image from last year:
http://www.pbase.com/strongmanmike20...15236/original
to our combined Lum + Ha to give an LHaRGB and it looks pretty good, although the stars are lacking a bit in colour and given the significant difference of the visibility in the the outer faint extensions these areas were hard to process to match in. Adding straight RGB or indeed an LRGB to the Lum+Ha would do the trick but I could only use what I had and this result looks pretty natural in my opinion..take a look at the result:
http://www.pbase.com/strongmanmike20...55503/original
This was using a non ideally matching data set of course and was processed on the fly. Your FOV is somewhat larger and more suited to framing the main body of the Helix so when you have your matching data sets you should be able to compile a really great colour image!
Now that I have this huge chip, your Lum and my playing around has inspired me to have another go at her myself and shoot for the extensive faint outer envelopes that exist around the Helix trippling it in size....of course, like your area seems to do to, Newcastle may not cooperate?
Hope you didn't mind too much me playing around with your data, it was certainly rather fun
Cheers
Mike