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Re: IC410, Tadpole Nebula - HOO, SHO, Ha
Posted: Wed Nov 26, 2025 9:11 am
by Vesmaobs261
Hi Dave,
Glad to be of service.
Looking forward to your future images.
George.
Re: IC410, Tadpole Nebula - HOO, SHO, Ha
Posted: Wed Nov 26, 2025 8:37 pm
by turfpit
Last night I managed to capture a further 15 frames of Ha and 10 frames of OIII - all at 450s. This takes the total integration to 8.75h (30 Ha & 40 OIII). Every frame was dithered during capture and drizzle 2x was used during integration, giving a pixel scale of 1.56 arcsec/pixel (down from 3.11).
- HOO_mode2_final2.jpg (462.3 KiB) Viewed 858 times
MultiscaleLinearTransform was used at the linear stage for noise removal in the first 4 layers. Linear mask inversion was used to apply noise reduction only to the darkest areas.
This is a close up of the centre of the image. With more data and more exposure (no pun intended) to noise reduction techniques, the centre of the Starnet++ starless version looks like this:
- noise_reduction.JPG (46.13 KiB) Viewed 858 times
This is an Ha only version, showing how much Ha contributes to the overall image.
- Ha_final.jpg (433.91 KiB) Viewed 858 times
Dave
Re: IC410, Tadpole Nebula - HOO, SHO, Ha
Posted: Fri Nov 28, 2025 9:51 pm
by turfpit
This is a rework of the SHO version - SII 18x450s, Ha 15x450s, OIII 30x450s (7.8h total) - integration with drizzle_2x.
- SHO_final.jpg (475.23 KiB) Viewed 760 times
Plus a close-up of the central region. Denoise was applied via MultiscaleLinearTransform immediately after ChannelCombination while the SHO image was at the linear stage.
- noise_close_up.JPG (60.97 KiB) Viewed 760 times
Next task will be to capture some RGB stars and hopefully more SII.
Dave
Re: IC410, Tadpole Nebula - HOO, SHO, Ha
Posted: Fri Nov 28, 2025 10:52 pm
by oopfan
Beauty!!
Can't wait for the soon-to-come RGB stars!
Re: IC410, Tadpole Nebula - HOO, SHO, Ha
Posted: Sun Nov 30, 2025 8:14 pm
by turfpit
I have reworked this and documented the steps in the hope it may help others process noisy data. First the result from processing 30 x Ha and 40 x OIII.
- HOO_final.jpg (503.18 KiB) Viewed 680 times
These 4 parts document the processing of the Ha and OIII stacks to produce the image above.
Brian (@oopfan) - the RGB stars will be along as soon as the weather permits.
Dave