Light pollution greatly limits astrophotography, especially if you use color cameras (both DSLR and cooled CCD cameras). In fact, when we want to record colors in a single picture, we inevitably also record wavelengths corresponding to light pollution. In order to reduce this effect, often UHC or CLS filters are used but they vary the colors of photography.
Instead, the LPS (Light Pollution Suppression) filter, thanks to its particular bandwidth, reduces light pollution while maintaining a very good color balance. Decreasing the brightness of the sky background, it will let you double the possible exposure time improving your pictures!
The image on the right shows the comparison of the M42 Orion Nebula recorded with the same Airy Apo 120 telescope, the same color CCD camera and 120 seconds of exposure time. You can see that:
- the sky background without filter is highly "light polluted" while with the filter it becomes much darker and neutral
- the colors are not altered: the nebula and the star at the bottom maintains its color
The second image shows a comparison made taking picture of the Pleiades (M45) with Airy Apo 80 telescope and Canon EOS 60D DSLR camera, both with 300 seconds.
