Flaming Star Nebula (IC 405), M38 and the Tadpoles

This image is a widefield around the Flaming Star Nebula in the constellation Auriga, that also includes other objects such as the Tadpoles, the M38 cluster (top-left of the image), etc.

I started taking 20x10' of L and 5x5' (bin 2x2) of each RGB. This was last Saturday from the DARC Observatory.

When I started processing it, and as I was trying to pull out the fainter nebulosity, the stars started to dominate the field. I simply couldn't contain them no matter what I did. So on Monday I decided to take a short trip to Montebello and captured 6x20' of H-Alfa, to see if then, with more signal in the nebulosity and smaller stars I could better manage the image.

I added 20% of the processed luminance to the also processed Ha, but I didn't add any Ha to the color - I used only the color information from the RGBs. The Ha left the better SNR areas a bit soft but I was much more pleased with the results.

The color was originally a bit unconvincing, so I first did a color calibration by selecting an area mainly packed with white-looking stars and balance the whole image assuming the average color of the stars in that selecion was indeed white. After that I neutralized the background taking one small area as a reference.

What I realized however is that I am no longer going to take RGBs binning 2x2, unless I'm dealing with an emergency - such as not enough time and evaluating that I will definitely get better SNR if I bin 2x2. The reason is what others have mentioned and that I could really notice this time. Basically after adding the color I could notice a very obvious ringing around many stars, ringing that wasn't nearly as obvious by looking only at the luminance.

It's a very interesting field, packed with interesting objects not often seen all in the same image. I hope you like it!

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DATE November 21st, 2009 PHOTO Exposure: L: 20 x 10', RGB: 5x5' each, Ha: 6 x 20' Total: 6.6 hours Focal: 385mm, f/3.6

EQUIPMENT Imaging Scope: FSQ 106 EDX w/Reducer Camera: STL11k Guide Camera: StarShoot Autoguider Imaging Scope: EM-400

SITE & CONDITIONS DARC Observatory    Seeing: Very Good    Transparency: Good Montebello OSP    Seeing: Very Good    Transparency: Average SOFTWARE Stacking: DeepSkyStaker Processing: PixInsight & Photoshop