Περιγραφή
New L-Ultimate Filter – Dual H-alpha / Oxygen III 3nm Ultra-Narrowband Filter
For One Shot Colour CCD / CMOS / DSLR Imaging – Simultaneously Capture H-alpha and Oxygen III
The advantage of L-Ultimate is that it only passes through the emission lines OIII(500.7nm) and Ha(656.3nm), in which case all other light pollution emission lines are eliminated so that only the emission and reflection signals of the nebula are captured during imaging. Therefore, the sky background of the image is darker, and the contrast between the nebulae and the signal-to-noise ratio are improved to the greatest extent. In heavy light pollution areas, the product can also selectively filter light pollution and clutter signals through the emission lines of nebulae, and finally avoid the impact of light pollution on astrophotography.
It is different from the series of dual-narrowband L-eNhance and L-eXtreme in that L-Ultimate is a dual-3nm bandwidth filter that only passes through Ha and OIII emission lines. You will get a darker sky background, more contrast of the image and the suppression on stars. L-Ultimate has also been optimised in terms of halo performance, so that there is no obvious halo when shooting on a bright star object.
Suitable for use with DSLR, colour/MONO CMOS and CCD astronomy cameras and telescopes with f-ratio f/4 or slower.
- High transmission of H-Alpha and Oxygen III emission lines (avg. 90% or higher)
- FWHM: Ha 3nm, OIII 3nm
- Use with colour DSLR, CMOS and CCD Cameras
- 2″ Mounted Filters.
- 300-1000nm >OD4 Blocking Range
- Supplied in a protective plastic case with EVA foam lining
- B270 1.85mm Thick Glass
- Fine-optically polished on both sides – ensures accurate λ/4 wavefront and <30 seconds parallelism over the both surfaces
- Ultrasonic wave cleaned substrate with purified water – Cleanup by 13 stage purified water tank to remove impurities and dust effectively
- Ion source assisted coating— For durability and resistance to scratching, as well as stability on CWL (central wavelength) – no deviation affected by temperature change
- Stringent quality testing process – each filter is tested on a spectrophotometer and laser interferometer
