BroadlandAstro

How I Capture & Process

This is a high-level tour of how I work — it isn’t a full tutorial; it’s the shape of my workflow so you know what goes into the pictures. I’ve added examples from raw frames to the final image so you can see the progression.

Capture

Gear: Until 2024 a modest 70 mm f/5 APO quad refractor; more recently a 200 mm f/8 Ritchey-Chrétien. Dedicated mono astro camera on a guided AZ-EQ mount.
Targets: Chosen for season and altitude. I revisit favourites across years.
Subs: As many sub-exposures (minutes each) as I can reasonably collect, often over multiple nights, to beat noise and weather.
I’ll usually spend a night or two testing framing and exposure length before the main imaging runs.

Calibration, stacking & processing

I now exclusively use PixInsight for processing.

Calibration: Darks, flats and dark flats applied (bias not needed with my camera).
Registration: Align all subs precisely.
Integration: Combine to masters; I usually add drizzle integration to improve resolution when sampling allows.
Linear work: Background neutralisation, gradient removal, noise reduction, deconvolution.
Channels & colour: Choose palette, fix imperfections, then combine channels. I often run a second round of linear noise reduction to tame any noise introduced by combination. Colour calibration as needed.
Stretch: Initial stretch from linear to visible image.
Post-stretch checks: Inspect for artefacts, control/reduce stars, and enhance detail to draw attention to specific regions.

Iteration

Most of my finished gallery pieces are second or third passes of the same data. Skills improve; software improves; so do results. More data always helps.

← Back to About • Info

Note: where a screenshot shows two panels side-by-side, the left is the raw frame; the right is a simple “screen stretch” to visualise faint signal.

Single 10-minute H-alpha sub-exposure showing some Flying Bat Nebula detail — Single 10-minute sub-exposure in hydrogen-alpha (H-alpha). Shows some detail of the Flying Bat Nebula.

Calibrated, cosmetically corrected, registered 10-minute H-alpha exposure — Calibrated, cosmetically corrected, and registered single 10-minute H-alpha exposure.

H-alpha master integration revealing the Flying Bat Nebula clearly — Calibrated, integrated H-alpha master (7 hours total). The Flying Bat Nebula is now clearly visible.

Single 15-minute OIII sub-exposure with very little Squid Nebula visible — Single 15-minute sub-exposure of the same region in O III. Very little of the Squid Nebula is visible.

Calibrated, cosmetically corrected, registered 15-minute OIII exposure — Calibrated, cosmetically corrected, and registered single 15-minute O III exposure.

OIII master integration representing 23 hours of data — Calibrated, registered, integrated O III master (23 hours total).

Initial HOO channel combination of H-alpha and OIII masters — Initial channel combination of H-alpha and O III masters into a colour image (HOO palette).

Colour image after background neutralisation, noise reduction, deconvolution and colour-noise reduction — After background neutralisation, noise reduction, deconvolution, and colour-noise reduction.

Left: starless nebulosity. Right: star field. Inset mask used to boost the Squid without lifting the Bat background, separated with StarXTerminator. — Left: starless nebulosity. Right: star field (separated with StarXTerminator). Inset on the right is the mask used to increase Squid Nebula detail/colour without lifting the red background of the Flying Bat. Stars refined for a cleaner look.

Final image after minor finishing tweaks in PixInsight — Final image (minor finishing tweaks in PixInsight).