LRGB Filters

How an LRGB Set Works Together

The value of a set lies in the relationship between its filters — parfocality, transmission balance and blocking — rather than in each one alone.

• Luminance: A broad filter blocking ultraviolet and infrared while passing the full visible range, gathering the most photons and therefore carrying the image's detail.
• Red, green and blue: Colour separation with carefully placed cut-on and cut-off points, so channels do not overlap and colours remain distinguishable.
• Transmission balance: Sets designed so that near-equal exposure across channels gives neutral star colour, which removes a large amount of processing guesswork.
• Parfocality: Matched optical thickness so refocusing between filters is minimal, which matters most at fast focal ratios with narrow critical focus zones.
• UV and IR blocking: Essential in refractors, where unblocked infrared reaches a different focus and bloats stars noticeably.
• Sizes and mounting: Sized to your sensor diagonal and filter-to-sensor distance, mounted for standard wheels or unmounted to maximize clear aperture.

Why Choose David Astro for LRGB Filters

A mismatched set costs you processing time on every image you ever take with it.

• Buy the set, not the pieces: We recommend matched sets because transmission balance and parfocality only exist across a designed group, not across mixed brands.
• Size calculated: We work out the filter size from your sensor diagonal and the distance from filter to sensor, so corners are not vignetted.
• Spacing accounted for: Filter thickness shifts focus, and we include it in the back-focus calculation supplied with your order.
• Authorized dealer: Genuine filters with verified coatings and full manufacturer warranty, in Canadian stock.
• Ships from Canada: No duties or brokerage fees for Canadian buyers.

LRGB Filters in Canada — Frequently Asked Questions

How much luminance versus colour should I shoot?

A common starting ratio is roughly half your total time in luminance and the remainder split across red, green and blue. Colour data can be binned or shot in poorer conditions since it carries less detail.

Do I need UV and IR blocking?

In a refractor, yes — a doublet or triplet does not focus infrared with the visible range, and unblocked IR bloats stars. In a reflector it matters less, but a blocking luminance filter is still standard practice.

Can I mix filters from different sets?

You can, but you lose the transmission balance and parfocality that make a designed set convenient. Expect more colour calibration work and per-filter focus offsets.

Is LRGB better than one-shot colour?

It resolves more detail for a given sensor and allows narrowband later, at the cost of roughly three to four times the imaging time per target and a filter wheel in the train.

Moving to monochrome imaging?

Tell us your camera and wheel and we will specify the set and sizes. Ships from Canada, full warranty.