M42 OIII work in progress

[blueskies123_89]

Hi,

Since forecast says rain for the next week, I thought I would post this here whilst I wait for clear skies.

Taken with Orion ED80, unmodded Canon 400D prime focus on an EQ6, with Thousand Oaks 2" OIII filter, over three nights in the last two weeks.

59 x 10min ISO 400 (~10 hrs)
Will take shorter exposures for the core some time later.

I hope to add colour data during this new moon, to make an OIIIRGB. No where near as good as Ha, but for an unmodded dslr, OIII is the only thing I can do during full moon.

Cheers
George

[AlexN]

Very nice mate!

I will say this, on M42, I find OIII gives better results than Ha anyway... Adding OIII as both a Luminance and blending it with your blue channel gives good results too.. Its always worth experimenting with these data sets.. But definitely give OIII R G OIII+B as L R G B a go...

You've shown great dedication capturing 10 hours of OIII data, and the data so far looks great.. Perhaps a tad noisy given 10 hours of exposure, how did you go about creating the monochrome image? did you just desaturate the image from the DSLR, or did you remove the green and blue channels and use them as a separate image? The red channel will likely be nothing but noise, it would be worth making sure you remove it from the equation...

Great work so far George! I can not wait to see final!! :D

[dugnsuz]

Ooohh very nice George.
I like where this is heading!
Huge amount of data too
Doug

[multiweb]

:eyepop:Sharp as a tak! :thumbsup: Can't wait to see the final combined.

[blueskies123_89]

I agree, it does seen quite noisy, I did do a unsharp mask but the original stack was still too much noise for a 10hr. Here is how I stacked it, see if you can find the problem:

-stacked in batches of ~2hr as that's how long each session was, such that each sub can be matched to the correct flat for that session
-stacked with kappa-sigma clipping in DSS, at 2x drizzle.
-Used the same 16 darks for each batch of 2hr
-Stacked the 5 resulting "autosave.tif" with the Average method and no drizzle.

I wonder if I should stack them all at once.. but then the flats wouldn't match; or that I used to few darks, but 16 darks for a batch of ~12-15 subs seems right.

EDIT: I did delete the red channel. It recorded a nice trapezium though...




Thanks guys! I cant wait to do the colour -> looks outside -> rain

George

[Hagar]

Very nice George. The OIII seems to have worked very well on this nebula. This will be a vey nice Lum channel when you get your RGB.

Look forwardto seeing the rest when finished.