HA O3 S2 Balance question

[irtuk]

I am setting up an imaging run for tonight as it looks like it will be clear. Currently I have 10 minute subs and I have 5 each for HA O3 S2 and Luminance. Is there a recommended, or even suggested balance between these channels? do I need more of one and less of another?

The constant battle with the clouds leads me to think if I can capture more of the right data it would be an improvement!

Ed

[vlaiv]

Why do you shoot luminance with narrowband? That is defeating the point of doing narrowband in the first place.

Divide your imaging time between Ha, OIII and SII.

In general - OIII will be much fainter than Ha and SII will be fainter still. However this depends on target.

How much you capture of each will depend on how you process your data. Ha being the strongest - needs the least amount of time to reach set SNR. However, if target is such that you can use Ha as luminance - then higher SNR for it will be beneficial as luminance needs more SNR - we are far more sensitive to detail in luminance than in chrominance data and will see noise in luminance much more.

[irtuk]

You see that's why I ask the dumb questions

 

Thanks Vlaiv

 

[newbie alert]

I agree with Vlaiv,  no need for luminance  as you can use the ha as a luminance layer

Luminance contains all the broadband spectrum range

No such thing as a dumb question

[old_eyes]

Narrowband exposures vary with object. Some have Ha and O3 but almost no S2 (Veil and Crescent nebulae). Some are rich in Ha and S2 but weak in O3 (California - at least when I image it!). SOme are rich in all three. If I am dealing with a target with emission across all three filters, my starting point is 2:3:4 Ha:O3:S2. 

The easiest way to find out it to look at other people's renditions of your chosen target - here or on astrobin. That often gives you an idea what works. For example, layered over the strong Ha of the FLyign Bat nebula, is the faint O3 signal called the Squid. You need insane amounts of subs to pull that out of the background.

So the answer to your original question is - it depends. I always rely on those who have gone before me and publish the results of their efforts.

And then when you have the data there is the whole question of colour palettes and blends. Narrowband is fun!