This combo is basically the cheat code for SHO-style nebula imaging with a color (OSC) camera. You get two separate 3.5nm DualBand filters—one for Ha+OIII and one for SII+OIII—so you can split Ha and SII into separate channels while also collecting twice the OIII data (because OIII is present in both filters). The result: cleaner channel separation, more usable signal per night, and serious performance in bright moonlight or extreme city light pollution.
Bundle includes both DualBand ULTRA filters for a lower price than buying separately
Designed for One Shot Colour (OSC) CMOS cameras (also useful with mono for luminance-style data)
Enables proper SHO/Hubble palette workflows with a color camera
Ha and SII are separated into different filters
OIII is captured in both filters, giving 2x the OIII data when used together
Built for bright moonlight and extreme light pollution (major city center conditions)
Ultra-narrow 3.5nm FWHM with steep bandpasses for maximum contrast and signal vs background
OD6 blocking (≈0.0001%) across most unwanted wavelengths for strong suppression of skyglow and artificial lighting
Halo suppression anti-reflective coatings for cleaner stars
UV/IR blocking included (works with modified and unmodified DSLRs too)
Strong performance with fast optics
Best performance at focal ratios as fast as f/4.8, with contrast improving as focal ratio slows
Standard 2" M48x0.75 thread
Fits standard 2" filter wheels and holders (including Altair magnetic holders and common DSLR lens-to-camera adapters)
Individually tested and certified
Each filter includes its own professional spectrographic test report (0.1nm resolution), not a generic batch report
Specifications
Format: 2" mounted, M48x0.75 thread
Set contents:
DualBand Ha + OIII ULTRA (3.5nm)
DualBand SII + OIII ULTRA (3.5nm)
Bandpass width:3.5nm FWHM (steep bandpasses for high contrast)
Blocking:OD6 (≈0.0001%) over the majority of unwanted wavelengths
