Nebulae Uncategorized

A Set of Images of NGC7000, The North American Nebula. Is Ha data worth it?


A perennial favourite object to image in the summer and autumn months in the Northern Hemisphere.  I’ve imaged this target with multiple equipment combinations over the years.  For example, in One Shot Colour (OSC), in widefield and in a very wide field.

As part of the image I used my existing Ha dataset from 2018/2019 which consists of 48 x 600 second exposures.  I discuss capture of this image here.

48 x 600s Ha Image

I then captured the RGB dataset in October 2021.  This image is my first image set that I captured using the excellent NINA (Nighttime Imaging “N” Astronomy) imaging software.  I captured four hours of RGB data through Astrodon 31mm E series Gen 2 filters binned at 1×1.  This consisted of 300 second exposures.  Seeing and transparency were not good but clear nights have been very infrequent in the UK in the past six months so I went for it regardless.

Four Hours of RGB data

I am very impressed with the quality of the standard  RGB image above.  Since the data is binned 1×1, I did not feel the need to capture any luminance channel at all.  Indeed the RGB alone is so good that the Ha data addition, whilst it does add some signal, adds so little to the final result that I question the time I spent capturing the Ha data.  For sure, the Ha image is a pretty picture all on its own.  However, it does add something to the picture as detailed below.

With Ha
With Ha Added - HaRGB
No Ha added - plain RGB

Despite the expense in time of gathering the Ha data, you can see that when it is blended with the RGB it brings out some fainter structures in the nebula.  Whether or not a full eight hours is needed though, I doubt.

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