# O-III 1.25" Narrowband Filter by Baader, 6.5 nm Bandwidth for CMOS Imaging

**URL:** https://aio.lv/en/product--oem-2961175--11022944
**Data updated:** 2026-03-20 09:47 (EET)
**Category:** Telescopes
**Manufacturer:** OEM
**Manufacturer code:** 2961175
**EAN:** 4047825047120
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 139.49 €
**Prices and availability valid until:** 2026-07-16 23:59
**Price without VAT (21%):** 115.28 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--oem-2961175--11022944

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 26.06.2026 | free |
| Pickup points | 01.07.2026 | 1.99 EUR |
| Courier delivery to door | 01.07.2026 | 4.99 EUR |

## Summary description

Baader O-III 1.25" narrowband filter with 6.5 nm bandwidth designed for use with CMOS astronomy cameras. It transmits oxygen-III emission lines while blocking other wavelengths to improve contrast in nebula imaging. Fits 1.25" focusers and adapters; suitable for visual observation and astrophotography to enhance faint emission details and reduce light pollution effects.

## Long description

The Baader O-III 1.25" Narrowband Filter with a 6.5 nm bandwidth is designed for use with CMOS astronomy cameras and 1.25" focusers and adapters. The filter selectively transmits the oxygen-III emission lines near 495.9 nm and 500.7 nm while strongly attenuating other wavelengths, which enhances contrast of planetary nebulae, supernova remnants and other oxygen-rich emission nebulae. Its 1.25" cell makes it compatible with common eyepieces, filter wheels and camera adapters for both visual observation and astrophotography.
Advantages
The narrow 6.5 nm passband increases contrast by reducing background continuum and light pollution without requiring extremely long exposures. Designed for CMOS imaging, the filter provides stable transmission across the intended passband and minimizes out-of-band leakage. The compact 1.25" format allows easy integration into existing optical trains and standard filter holders, enabling quick changes between filters during imaging sessions.
Suitable for
 Enhancing contrast of planetary and diffuse emission nebulae (O-III dominated regions)
 CMOS astrophotography with small to medium aperture telescopes
 Visual observation of faint emission nebulae under light-polluted skies
 Use in 1.25" filter wheels, eyepieces and camera adapters
Key specifications
 Filter type: Narrowband O-III (oxygen-III) transmission
 Diameter / cell size: 1.25 inch (standard 1.25" filter cell)
 Bandwidth (FWHM): 6.5 nm
 Designed for: CMOS imaging and visual use
 Primary transmitted lines: O-III emission near 496 nm and 501 nm
How to use
Install the 1.25" filter into a compatible focuser, eyepiece holder or filter wheel between the telescope and the camera or eyepiece. For astrophotography with CMOS cameras, place the filter as close to the sensor as practical to avoid vignetting and ensure uniform illumination. Use standard calibration routines (darks and flats) when capturing narrowband data to correct for sensor noise and dust shadows. When switching between filters during an imaging session, allow the telescope to refocus if necessary due to slight optical path changes.
Usage recommendations
For best results, pair the O-III filter with targets that have strong oxygen-III emission such as planetary nebulae and certain supernova remnants. Under heavy light pollution, the narrow 6.5 nm bandwidth will improve contrast, but combining exposures with other narrowband filters or using longer total integration times can further enhance faint structures. Verify mechanical clearance in your imaging train to prevent vignetting when using the 1.25" cell.

## FAQ

### How much does the Baader O-III 1.25" Filter 6.5nm cost, and is it available for purchase?

The price is 139.49 € (valid at the time of publication and already includes all taxes). The item is available for order — 6 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on 26.06.2026 at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer, Bank cards on-line, Apple Pay, Google Pay, Installment. All transactions are 100% secure and encrypted.

### Can Baader O-III 1.25" Filter 6.5nm be purchased with a lease?

Yes, the purchase is available both on credit and with an interest-free installment plan. Learn more about installments and credit options: https://aio.lv/en/payment#b3

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All OEM products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized OEM service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

## Image

https://aio.lv/img/cache/product/11022944/65906431_large.webp