想问下CLS-CCD和CLS滤镜有什么区别？

想问下CLS-CCD和CLS滤镜有什么区别？
如果只是给ccd压下天光提高对比度买哪种

http://www.astronomik.com/en/pho ... mik-cls-filter.html
CLS:
Suitability
Visual observation (dark skies): Good, to reduce light pollution by mercury-vapour lamps (streetlight)
Visual observation (urban skies): Good, an UHC-E or UHC filter is more suitable
Film photography: Very good, colour balance is near perfect
CCD photography: Good, when used with an additional IR-block-filter
DSLR photography (original): Good, colour balance shifted but contrast enhanced
DSLR photography (astro modified): Very good, colour balance is near perfect
DSLR photography (MC modified): Good, when used with an additional IR-block-filter
Webcam / Video (Planets): Unsuitable
Webcam / Video (Deep Sky): Very good, if light pollution is a big problem
http://www.astronomik.com/en/pho ... cls-ccd-filter.html
CLS-CCD:
Suitability
Visual observation (dark skies): Good, to reduce light pollution by mercury-vapour lamps (streetlight)
Visual observation (urban skies): Reasonable, an UHC-E or UHC filter is more suitable
Film photography: Very good, colour balance is near perfect
CCD photography: Very good, optimized rejection of light pollution
DSLR photography (original): Good, colour balance shifted but contrast enhanced
DSLR photography (astro modified): Very good, colour balance is near perfect
DSLR photography (MC modified): Very good, colour balance is near perfect
Webcam / Video (Planets): Unsuitable
Webcam / Video (Deep Sky): Very good, if light pollution is a big problem