Optolong L-Ultimate 2” Dual Bandpass Light Pollution Reduction Imaging Filter

Difference： It is different from the series of dual-narrowband -eNhance and L-eXtreme in that L-Ultimate is a dual-3nm bandwidth filter that only passes through Ha and Olll emission lines. You will get a darker I sky background, more contrast of the image and the suppression on stars. L-Ultimate has also been optimized in terms of halo performance, so that there is no obvious halo when shooting on a bright star object.. Advantage： 1.The advantage of L-Ultimate is that it only passes through the emission lines OllI (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.