Starship Asterisk*

geckzilla wrote:Looking at the blue channel alone the stars are spread out much larger than the green and red and detail has been lost in the central nebula where it has become pure white.

Edit: This is not to say that this is somehow wrong. I think it's fairly typical and I've done it a lot myself.

geckzilla wrote:

Ann wrote:The colors in this image are somewhat muted, and the blue channel has not been given a boost.

Blue is actually quite overexposed in this image. To me, this picture is quite colorful--the opposite of muted. I'm not sure how you could say that it's muted.

rgendler wrote:Strictly from an image processing perspective the entire image is shift towards red. Even the blue stars are shifted towards purple which confirms my suspicion. This was done I'm sure to maximally enhance the tendrils of emission nebulosity abundant throughout the field. I would bet that dropping the mid-level of the red channel using curves would improve the overall color balance tremendously.

I agree, it's very red. I would suggest some changes to be made using Photoshop's channel mixer rather than the curves. We can take the purple out of the blues by changing the red output. Modifying its input to take +30% from the green channel and -30% from the blue channel is sufficient. This will avoid sacrificing brightness. To reduce the pinkness of the nebula we can then adjust the green output by modifying its input to +10% red channel and +90% green channel. The result should look like this.

I should note that I don't find any fault with Damian's original work, personally. Purple is my favorite color, anyway. I may have done it differently if I had done it but I enjoy Damian's version a lot. I recognize that even though the stars appear purple absolutely, relatively they are bluer than the nebula and that is sufficient for my brain to interpret the stars as being bluer.

rgendler wrote:I like your version. The color balance is now much improved. BTW I wasn't trying to be critical of Damian's fine image. Anyone who does serious astronomical image processing knows the benefit of another pair of fresh eyes.

Chris Peterson wrote:

geckzilla wrote:Looking at the blue channel alone the stars are spread out much larger than the green and red and detail has been lost in the central nebula where it has become pure white.

Edit: This is not to say that this is somehow wrong. I think it's fairly typical and I've done it a lot myself.

I wouldn't choose the word "overexposed" for this. But certainly, the blue channel has had its intensity stretched more than the other two channels, with the result that the bright stars in the blue channel have been bloated. This results in blue halos around the stars in the full color image.

I like to work in LAB or HSL color spaces when processing astronomical images, because it largely prevents this kind of distortion.

geckzilla wrote:Lab confuses me. I use HSL (It is called HSB in PS) for my color sliders, though. That is a very sensible way to represent color. Munsell called it hue, chroma, and value. Apparently chroma and saturation aren't the same thing, though... I guess I have failed at making such a distinction for a long time.

Ron-Astro Pharmacist wrote:Is the mechanism that causes star formation from a supernova known?

One might think that energy being released from a supernova explosion would drive the gravitationally attracted material apart rather than causing it to aggregate more vigorously. :?:

Ann wrote: The colors in this image are somewhat muted, and the blue channel has not been given a boost. NGC 2070 is located nearly dead center of the image. Anyone looking for blue stars on the right of this picture will look in vain.

Elpatriarcasandokan wrote:In Spanish : Al acercarme se ven algunos discos con puntos en la mitad ?????
???????? ........ ?




?

geckzilla wrote:They're wondering about the black dots in the centers of stars. If anyone can translate this to Spanish say it's just where the CCD is saturated. It got so bright that it turned black.