Optolong L-Pro Filter 1.25" & 2"

The Optolong L Pro is a broadband light pollution suppression filter designed for astrophotography from both urban and dark-sky locations. It selectively blocks artificial light wavelengths while allowing essential nebula and starlight emissions to pass, making your images cleaner, sharper and far easier to process. It preserves natural star colors unlike aggressive narrowband filters, which makes it a favorite for imaging galaxies, clusters, dust lanes and reflection nebulae.
 
What Does the L Pro Actually Pass
The filter allows the following important emission lines used in deep sky imaging:
H Beta at 486.1 nm
Oxygen III at 495.9 nm and 500.7 nm
Hydrogen Alpha at 656.3 nm
Sulfur II at 672 nm
 
It blocks the most common artificial light pollution sources such as:
Mercury vapor emissions
Sodium street lighting
General urban glow
 
Bandwidth and Optical Performance
Multi-band pass design with multiple narrow pass windows
typical bandwidth: 100 to 110 nm across the total transmission area
High transmission (greater than 90 percent) at key nebula lines
Multi-layer anti-reflection coatings eliminate halos and ghost reflections
Made with precision polished glass for tight star profiles and improved SNR
 
Compatibility and Optical Speed
Works well with fast and slow telescopes (f ratios from f2 to f10 and beyond)
Well suited for refractors, Schmidt Cassegrains and Newtonian reflectors
Compatible with DSLR and mirrorless cameras, CMOS astronomy cameras, and filter wheels
 
Ideal Targets for the L Pro
Large galaxies and star clusters
Reflection nebulae
Wide field Milky Way star fields
Broadband emission targets
Dust lanes and dark nebula regions
 
Key Benefits
Retains natural color balance in images
Improves contrast in light polluted environments
Reduces gradients caused by city glow
Faster results with shorter total exposure times
Great for astrophotographers who want clean broadband data without heavy post editing