Used: TS-Optics 2" CLS broad band nebula filter for photography

TS CLS 2" broadband nebula filter for increasing contrast of deep sky objects

The City Light Suppression CLS filter from TS is optimized for photography of deep sky objects from the outskirts of cities. The artificial brightening by the cities is significantly reduced and thus the sky background is darkened, while nebulae and star clusters keep their brightness. The contrast is enhanced.

In opposite to the UHC filter which only transmits narrow spectral ranges close to desired lines, a CLS filter just blocks the range(s) where undesired lines lie. This results in the following differences between the filters:

CLS lets more light through and is therefore also suitable for observation through smaller instruments.

CLS is mainly made for astrophotography, it allows an extension of the exposure time by a factor of 3 until the sky background becomes noticeable.

Application areas of the TS City Light Suppression filter:

Astrophotography from the outskirts of the city, all deep-sky objects can be photographed with the filter.

Observation of deep sky objects with telescopes from 60 mm to 150 mm aperture

Transmission range of the TS CLS filter:

The filter has two transmission windows, exactly where gas nebulae and planetary nebulae radiate:

[O III] and H-beta region: between 420 nm and 530 nm the filter transmits about 95% of the light

H-alpha region: in this region astrocameras are very sensitive, so the passband is also high here.