M-101

Integration Times:

Night One:

6 x 5 minute luminance images
2 x 5 minute red images
2 x 5 minute green images
2 x 12 minutes blue images

Night Two:

6 x 10 minute luminance images
2 x 5 minute red images
2 x 5 minute green images
2 x 12 minutes blue images

Totals:

Luminance: 90 minutes
Red: 20 minutes
Green: 20 minutes
Blue: 48 minutes

Processing Notes:

Using MaxImDL:

Images had dark frames and flat fields taken and processed.
Images of like-color were summed after alignment.
A DDP FFT Low Pass was performed on the Luminance layer.
A raw, 16-bit, RGB TIF image was created.
A raw, 16-bit, luminance TIF was created.

Using Adobe Photoshop:

Both the RGB and Lum images were edited for correct levels.
The RGB image had borders expanded.
Color correction was performed on the RGB layer.
Color saturation was increased slightly on the RGB layer.
Both images were placed into 8-bit mode.
The luminance image was copied and pasted as a new layer onto the RGB image using it as the Luminosity layer.
Adjustments were made to correct positioning of the Lum layer.
A Gaussian Blur was performed on the RGB layer.
An unsharp mask was performed on the Lum layer.

Cosmetic blemishes were removed (hot pixels and such).
The image was cropped to final size with a black border added.
The image was flattened and saved as a TIF and a JPG.

Misc. Notes:

This object has a LOT of blue in it. The majority of stars, especially in the extended arms are young and blue.
There are some outlying regions of H-based nebulosity.
In processing, a mild amount of Local Adaptive Filtering was beneficial to bring out the contrast in the spiral arms. The previous attempt without this filter resulted in a lovely image, but with no real contrasts.