Optolong L-Pro Clip Filter for Sony Full Frame V2

1. The Optolong L-Pro Filter

The Optolong L-Pro (L-Professional) filter is designed to improve the visibility of many deep-sky objects. It selectively reduces the transmission of light pollution wavelengths, particularly those from artificial lighting (mercury vapor lamps, high and low-pressure sodium lamps) and unwanted natural light due to neutral oxygen emission in the atmosphere ("skyglow"). At the same time, it remains highly transparent to the main emission lines of nebulae: OIII (496 nm and 500 nm), H-beta (486 nm), NII (654 nm and 658 nm), H-alpha (656 nm), and SII (672 nm). For this reason, it is suitable for increasing contrast and detail, both for visual observation and photography, in peri-urban areas with strong light pollution.

Unlike other light pollution filters such as UHC and CLS, the L-Pro is a multiband filter that offers better color balance thanks to transmission bands that are as wide as possible. The balanced transmission allows you to photograph broadband emission objects, such as galaxies, reflection nebulae, and globular clusters, with minimal color casting. The L-Pro is the best choice for attenuating light pollution.

Main Use and Performance

Suitable for visual observation and astrophotography. The L-Pro filter attenuates the light of continuous-spectrum objects very little, so it is very effective against light pollution when imaging galaxies, reflection nebulae, and globular clusters; the same applies to the visual observation of stars. On its own, it also blocks infrared, so it can be used safely for luminance ("L") imaging with CCD cameras.

Light pollution filters do not eliminate the effects of light pollution and do not increase the brightness of objects: in most cases, they increase the contrast between the nebula and the sky background without making the nebula itself brighter.

WARNING: Optolong filters are not designed for solar observation. NEVER LOOK AT THE SUN WITH AN OPTOLONG FILTER: ignoring this warning can cause blindness.

2. Specifications of the Sony-FF clip filter (new mount)

• Material: optical glass
• Thickness: 1.0 mm
• Blocking range: 300-750 nm
• Blocking depth: light pollution lines blocked by over 90%
• Surface quality: 60/40
• Flatness: λ/4
• Parallelism: 30″

3. Compatibility

• Cameras: A7M / A7M2 / A7M3 / A7R / A7R2 / A7R3 / A7S / A7S2 / A7S3 / A9
• Lenses: entire range of E-mount lenses

Since it is impossible to test all lenses, Optolong has tested the most popular ones on the market.

4. Packaging

Silver outer box, plastic case (PP), high-density white EVA interior. Contents: L-Pro filter, triangular installation tool, and instructions.

Key Features

Optolong quality for a reliable and satisfying observation experience.

• Type: Filter
• Material: Schott glass
• Optical coating: multi-coated
• Frame: Clip Filter
• Transmission: 95
• Surface accuracy: 1/4

Main Technical Specifications