Optolong L-Ultimate Filter 1.25"
When will I receive it?
Products marked In stock are dispatched promptly — the exact delivery estimate for your address is shown at checkout, before you confirm the order.
For international shipments, delivery times depend on the destination and are always displayed at checkout before payment.
Products marked Available on order require 5–15 business days for processing. Our team will keep you updated promptly if anything changes.
What are the warranty terms?
Shop with confidence: all our products include a 24-month legal warranty for conformity defects, managed directly by our team.
Many brands also offer extended warranty coverage beyond 24 months — contact us to find out the specific terms for the product you're interested in.
Click here for more information.
Can I return a product?
Yes: you have 14 days from delivery to return any product and receive a full refund — see our Refund Policy for full details.
Items must be returned in their original condition and packaging. Return shipping costs are the customer's responsibility.
Not sure which product is right for you? Contact us before buying — we'll help you find the perfect instrument so you won't need to return anything.
Sei un'azienda? Compila il modulo per la fatturazione
Clicca sul pulsante qui sotto per inserire i tuoi dati aziendali:
Vai al moduloOptolong L-Ultimate 1.25" – 3nm Dual Narrowband Filter for Astrophotography
The Optolong L-Ultimate 1.25" filter is a dual band ultra-narrow 3nm filter, a direct evolution of the well-known L-eXtreme. Designed for those who want maximum light pollution suppression, it isolates with extreme precision the H-Alpha (656.3nm) and OIII (500.7nm) emission lines, bringing out even the faintest nebulae and enhancing the finest details.
The 3nm bandpass makes the L-Ultimate the ideal choice for astrophotographers working from urban and suburban areas with DSLR, CMOS (mono or color) or CCD cameras, allowing imaging sessions even under heavy light pollution. It shares build quality and coating with the rest of the Optolong range and can also be used on fast focal ratios down to about f/4.
Key Benefits
- 3nm bandpass: maximum suppression of every artificial light source
- Optimized transmission on the H-Alpha and OIII lines
- Compatible with focal ratios down to about f/4
- Usable with DSLR, mono/color CMOS and CCD
- Compact 1.25" format, ideal for lightweight setups and eyepiece trains
Technical Specifications
| Filter type | Dual Narrowband (H-Alpha + OIII) |
| Bandpass | 3nm (Ha 656.3nm + OIII 500.7nm) |
| Format | 1.25" (31.8mm) |
| Substrate | Schott optical glass |
| Surface quality | 60/40 (MIL-O-13830) |
| Recommended focal ratio | Down to f/4 |
| Recommended use | DSLR, mono/color CMOS, CCD |
The Optolong L-Ultimate 1.25" filter is the most advanced solution for emission astrophotography from compromised skies in a compact format, ideal for anyone using 1.25" eyepieces and optical trains.