A gaudy Cone and Christmas Tree

[don4l]

I'm not at all sure about this at all.  It looks completely different to anything that I have produced before.  The red seems to be a monotone, but maybe that is the way the object is. 

This consists of 210m Ha, 25m G and 20m Blue.  I did get another 50m blue, but there was a horrible glare around the brighter stars, so I couldn't use it.

This is the first time that I have used starnet on the individual colour channels before combining them.  Previously, I have just used it to remove bloated stars, and replaced them with a set that "I prepared earlier".

Equipment:  G3 16200, EQ6

Software: CCDCiel, CCDStack, Gimp, Starnet

Any comments very welcome.

 

 

Here is a screenshot that shows this image in relation to Orion and the Rosette.

[carastro]

I really like that.  Very nice.

Carole 

[tooth_dr]

Very striking! A lot to like.

So no Red, but Ha used as red?

[don4l]

21 minutes ago, tooth_dr said:

Very striking! A lot to like.

So no Red, but Ha used as red?

....emmm no!  No red.

This is Ha:G:B  with the Ha later applied as Lum, and also partially applied in "Overlay" mode in the Gimp.

I cannot explain why, but I usually leave red till last.  In this case,  I had intended collecting a lot more data before finishing the image.  However,  I don't know where to take it, so I thought that I would put it up and see what the reaction is.

If you asked me what might add to the image, then I would think more Green, or I would be tempted to try OIII.  However,  I would be the first to admit that I don't really get RGB, so I really am very open to advice.

 

[ollypenrice]

There are three fundamental problems with using Ha as red. 1) the signal from the stars is tiny in Ha so red is under represented. 2) The background is held down by the NB filter so it's hard to get a balanced background sky. 3) The red you have is highly selective, coming only from only one source of emission and it's almost monochromatic. While you have a broad blue spectrum and a broad green one you have only a highly restricted red one.

For all that, the image is attractive and it would be easy to reduce saturation in red if you wanted to. However, I think it would work even better if the Ha were applied to the red channel in blend mode Lighten.

There is a blue reflection nebula in the middle part of the cone which has little or no signal in Ha. This means that if you use Ha to illuminate the image you'll kill it.

Olly

[carastro]

Quote

This is Ha:G:B  with the Ha later applied as Lum

I think this has worked very well.  Sometimes I wonder why I bother to capture Red when I am adding Ha as the Ha quite overwhelms the Red.

I also add Ha as Luminance, there is sometimes some adjustment to be made to the colour to prevent it coming out Salmon pink, but I really like this idea even if as Olly says the sky background might be a bit difficult to achieve. 

Carole 

[don4l]

8 hours ago, carastro said:

I think this has worked very well.  Sometimes I wonder why I bother to capture Red when I am adding Ha as the Ha quite overwhelms the Red.

I also add Ha as Luminance, there is sometimes some adjustment to be made to the colour to prevent it coming out Salmon pink, but I really like this idea even if as Olly says the sky background might be a bit difficult to achieve. 

Carole 

I'm wondering if it something to do with light pollution.  On the other hand,  I've had some surprising success with galaxies recently where the  gradients didn't seem too awful.

[don4l]

10 hours ago, ollypenrice said:

There are three fundamental problems with using Ha as red. 1) the signal from the stars is tiny in Ha so red is under represented. 2) The background is held down by the NB filter so it's hard to get a balanced background sky. 3) The red you have is highly selective, coming only from only one source of emission and it's almost monochromatic. While you have a broad blue spectrum and a broad green one you have only a highly restricted red one.

For all that, the image is attractive and it would be easy to reduce saturation in red if you wanted to. However, I think it would work even better if the Ha were applied to the red channel in blend mode Lighten.

There is a blue reflection nebula in the middle part of the cone which has little or no signal in Ha. This means that if you use Ha to illuminate the image you'll kill it.

Olly

 

I think that the weak Ha stars are compensated by the different stretches that I apply to the Ha and G/B.  Each are stretched by eye in CCDStack.  The RGB combination seems to produce a balance similar to what I see in other images.

The background is a real issue, and I do not really like the plasticy look that results.  My processing method makes the problem much worse.  I duplicate the final image and blend it with itself using "overlay" mode.  This seems to highlight areas of interest (eg the tadpoles) but it does suppress the background.

 

I've looked at my blue data, and I cannot see any discernable signal in the middle of the cone.  There is a small bit just below the tip of the cone, and I have added this to the Lum layer.  When the moon goes away, I will try to get another hour of Blue which will be much easier to use.

This is what I got by adding the blue and reducing the saturation a bit:-

 

[MartinB]

This is a very dramatic image and I love the interaction between the Ha region and the reflection nebulosity.  However, I don't think it is finished!  No matter how you twist things around in processing you will never get an Ha channel to perform as broadband red.  A relatively small amount of time on a proper red channel will bring your stars to life and give you more flexibility with your Ha.