Optolong L-Pro (L-Professional) is a multi-bandpass filter which selectively suppresses the transmission of light pollution lines. For example, mercury vapor lamps, high and low pressure sodium vapor lights and skyglow caused by emission from neutral oxygen in our atmosphere.
L-Pro enhances the transmission of major emissions from nebula while offering great colour balance with its wide yet effective light pollution cutting transmission band. The balanced transmission allows objects with wide emission spectrum such as galaxies to be imaged with minimal colour cast (easier to correct in post-processing). Among the emission lines enhanced are OIII (496, 500nm), H-beta (486nm), NII (654, 658nm), H-alpha (656nm) and SII (672nm).
- 90% transmission at major nebula emission lines
- Multi-layers anti-reflection coating
- Precise and sharp roll-off at light pollutant lines
- 2 mm filter thickness (1.25", 2" and 77mm) | 1mm (clip series)
- Made on Schott substrate
- Finely polished to 1/4 wave accuracy
- Surface quality: 60/40 (MIL-O-13830 standard)
- Monochrome & one-shot-colour CCD/CMOS camera
- Deep sky colour imaging, particularly reflective nebula and galaxies
Before & After
Direct JPEG output
Author: Jerry Huang
D810A, 180s, ISO1600, FLT132
L-Pro Superior Colour Balance
The comparison image says it all.
Available in sizes
- 1.25" (26mm clear aperture)
- 36mm round unmounted
- 2" (45mm clear aperture)
- Multi layers anti-reflection coating
- Non cementing optical substrate coating
- Electron-beam gun evaporation with ion-assisted deposition coating technology to enhance coating durability and resistance to scratching as well as stability on central wavelength such that passband does not deviate with temperature change
- Planetary rotation system offers high precision and homogeneity of coating surface ensuring high value on passband transmission and off-band blocking.
Filter cell technologies
- CNC machined with aerospace grade aluminium
- Black anoidised finish and extinction treatment to prevent refection
- Laser engraved fade-free wordings
We care about delivering your filter in perfect form and thus every Optolong filter sits on a high density sponge carton lining and packaged in highly rigid plastic PP case with high pressure EVA case lining.
|NGC6559 by Jerry Huang
Mount: Paramount MX
Optics: William Optics FLT-132
Camera: Nikon D810A
Filter: Optolong L-pro
Exposure: 15x300" ISO800, 10x600" ISO800
|Author: 星河小將 (China)
Mount: iOptron CEM25
Optics: Sharp Star 65Q
Filter: Optolong L-pro
Total exposure: 105 mins
Optolong is a brand dedicated for astronomical filters R&D and production under Kunming Yulong Optical & Electronics Technology Co. Ltd. Yulong is a professional manufacturer of high quality filters since 1999. Yulong has passed ISO9001 quality certifcation and all products meet ROHS standard authorised by SGS test.
Their major equipment include ultra clean room, five precise vacuum coating machines, Shimadzu UV-VIS-NIR spectrophotometer, 12 sinks ultrasonic cleaning machines and grinding/rolling/cutting machines.
Optolong filters only use the best glass — German's Schott glass as the substrate which has an industry leading level of flatness which is crucial to minimise the occurence of halo and ensure high quality image.