Heart nebula narrowband help pls :) - Forums

Topic starter

Sep 22, 2023

Hey all. Still learning and looking for advice.

I’m thinking I’m going to target IC 1805 with my 65phq/asi294mm pro.

Should I stick to just ha/sii/oiii, or should I shoot L as well? I’d like to have a final image that is saturated with blues/reds etc. a nice colourful pic that I can print as art. Is there any merit in capturing more sii/oiii than ha? I’ve split my imaging time equally lately just because ¯\_(ツ)_/¯ ?

thx in advance!

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Sean Mc

Topic starter

Sep 23, 2023

Bueller?

Brian Puhl

IOTD Staff

Sep 23, 2023 · Edited: Sep 23, 2023

Colors are the artists preference.   Typically a red/blue image is HOO, but you can assign a color channel to any filter honestly.   That's why theres HOO, HSO, SHO, HOS, etc…

Ha is typically the strongest signal.    You can get away with the least time on it.     Oiii is typically the weakest, requires little to no moon (for a clean signal), and occupies most of our time in narrowband imaging.   Sii is generally weak, but provides alot of detail in an SHO image.

You should not shoot luminance for narrowband, it will only hurt the image in the end.   Luminance is for RGB.

Typically I shoot Ha and Oiii, and from there decide if I want to continue and shoot Sii.   My skies are hit or miss and often I would rather move on to another target than shoot Sii.

Generally speaking, I shoot for 60 subs if I can, minimum, which builds up pixel rejection for the final stack.   Less subs and you'll find those pesky satellites will show up in your final image.

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Joe Linington

Sep 23, 2023

Some tricks if you are shooting SHO (can apply to other colour combinations but very useful for SHO). Shoot Ha for a Lum, what I mean is you can use the Ha channel as if it were a Lum channel. This is particularly helpful for SHO compositions because you often remove much of the green with SCNR/Green Noise Removal which is that beautifully detailed Ha channel. When you put the Ha channel back in as a Lum channel it brings back that detail and often reduces the noise a lot.

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Sean Mc

Topic starter

Sep 23, 2023

Awesome. Thx for the knowledge transfer!

Mogan Andrei

Sep 24, 2023

Based on your equipment you will have a tight view of the IC 1805 (if you are not planning to go mosaic). From my experience with this target, I would insist on the OIII and try to get a good, noise free integration from that filter.

If you are not planning to go >15h on the target, I would just shoot Ha and OIII for an HOO palette. This will get you enough information to create the desired image. In this situation I would take 50% more OIII subs than Ha (clear nights, no moon) and just take Ha on nights with the moon out.
If you are planning to go over 15h on the target, taking SII subs will help you to define the details better. The importance of the filters is OIII>SII>Ha. I would suggest the following percentage: 40% OIII, 30% SIII, 30% Ha. Ha and SII can be taken on nights with moon.

Of course, this is subjective and it depends on your current workflow, the desired result and how do you want to use your filter information for your image.
Here is an example of how the 3 filters will look independently (https://www.astroworldcreations.com/image-details/ic1805-heart-nebula) . This will give you an idea of the signal they will produce and what areas can you enhance with that information. If you want more Ha details, bump the Ha, if you want more details in the SII, bump that.

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