compose module

[NGC664]

Hi, Can I take a stacked dslr /triband filter fts file and just import for Ha band only ? Trying to minimize moon glow tonight. Not sure if this is possible and what option I would use. I am rather new at this. Thank you

[admin]

Sure is! In the Compose module, simply load the the dataset as "Red" an you're done.
This will extract the red channel (in which the Ha is obviously located).

You can also load the same dataset in all channels (red, green, blue) and set "Red Total Exposure" to any value, while setting Green and Blue Total Exposure to 0. What this does, is giving you the pure detail from the red channel (which is the Ha), however with the full coloring from all channels.

The latter will let you show Ha detail, but also give your viewers an indication where O-III exists alongside Ha by means of a different color hue.

Welcome to narrowband processing - it's an incredibly rewarding type of astrophotography with lots of ways to use and present your data. StarTools, however, tries to make this complex type of processing as easy a possible.

[opestovsky]

You can also load the same dataset in all channels (red, green, blue) and set "Red Total Exposure" to any value, while setting Green and Blue Total Exposure to 0. What this does, is giving you the pure detail from the red channel (which is the Ha), however with the full coloring from all channels.

Hi.
Two questions:
1) What do you mean exactly by "full coloring from all channels?" How is such data going to be different from loading just a single Red channel?
Also, there's no "0" setting - it says "not set" in the stable version. Is this a feature of the beta version?
2) Are exposure settings only used in generating a synthetic L or are they used somewhere else as well, for example, in the color balance of the Color module?

[admin]

Hi.
Two questions:
1) What do you mean exactly by "full coloring from all channels?" How is such data going to be different from loading just a single Red channel?
Also, there's no "0" setting - it says "not set" in the stable version. Is this a feature of the beta version?
2) Are exposure settings only used in generating a synthetic L or are they used somewhere else as well, for example, in the color balance of the Color module?

1) Luminance (detail) and Chrominance (color) is processed strictly separately (but in parallel!) in StarTools. You can use the detail of just the Ha, but the coloring of the Ha+O-III. Your reasoning is that the detail is washed out because of the moon. This may well be valid. You can still, however, used the "washed out" coloring of the full Ha+O-III set without too much problems. (indeed 0 means not set).
2) Per the docs, the exposure time settings are purely used to create the correct weighted synthetic luminance dataset. It has not bearing on coloring.

[opestovsky]

Hi.
Two questions:
1) What do you mean exactly by "full coloring from all channels?" How is such data going to be different from loading just a single Red channel?
Also, there's no "0" setting - it says "not set" in the stable version. Is this a feature of the beta version?
2) Are exposure settings only used in generating a synthetic L or are they used somewhere else as well, for example, in the color balance of the Color module?

1) Luminance (detail) and Chrominance (color) is processed strictly separately (but in parallel!) in StarTools. You can use the detail of just the Ha, but the coloring of the Ha+O-III. Your reasoning is that the detail is washed out because of the moon. This may well be valid. You can still, however, used the "washed out" coloring of the full Ha+O-III set without too much problems. (indeed 0 means not set).
2) Per the docs, the exposure time settings are purely used to create the correct weighted synthetic luminance dataset. It has not bearing on coloring.

1) This is not my thread, so I don't know anything about any Moons.
I caught a phrase you used whose meaning was unfamiliar to me.
Let me rephrase my question.

What is the difference between:
a) open Compose,
load OSC/dual narrowband fits file into Red,
press Keep.

vs.

b) open Compose,

You can also load the same dataset in all channels (red, green, blue) and set "Red Total Exposure" to any value, while setting Green and Blue Total Exposure to 0. What this does, is giving you the pure detail from the red channel (which is the Ha), however with the full coloring from all channels.

,
press Keep?

Thank you.

[admin]

What is the difference between:
a) open Compose,
load OSC/dual narrowband fits file into Red,
press Keep.

vs.

b) open Compose,

You can also load the same dataset in all channels (red, green, blue) and set "Red Total Exposure" to any value, while setting Green and Blue Total Exposure to 0. What this does, is giving you the pure detail from the red channel (which is the Ha), however with the full coloring from all channels.

,
press Keep?

Compose >load color dataset only into red, will - without any further parameter tweaks - use only the red channel for luminance. You will be processing a mono image, and the image will remain mono in the Color module.

Compose >load color dataset only into red, green and blue, while setting Green/Blue Total Exposure to 0, will - without any further parameter tweaks - use only the red channel for luminance, and the full red/green/blue coloring as recorded for chrominance. You will be processing a mono image, and the image will be colored in the Color module.

Does that help?