![]() ![]() DSLR photography (original): Good, colour balance is near perfect.CCD photography: Good, when used with an additional IR-block-filter.Film photography: Good, but very long exposure times.Visual observation (urban skies): Good, for telescopes up to 125 mm aperture and medium exit pupil.Visual observation (dark skies): Reasonable, an UHC filter is more suitable.The major emission lines of artifical light pollution: The most important lines are from ionized Hydrogen (H-alpha and H-beta) and The most important emission lines from nebulas are shown in green.Which are used in nearly all streetlights. The artifical light pollution is dominated by see mercury (Hg) and sodium (Na), The most important artifical emission lines are shown in orange.Photographic filters: The grey line in the background shows the sensitivity of a typical CCD sensor.You can easily see, that you can´t see anything of the H-alpha line at night (even if you can during daylight!) The sensitivity at The maximum is at ~510nm and drops to longerĪnd shorter wavelengths. Visual filters: The grey line in the background shows the relative sensitivity of the human eye at night.The red line shows the transmission of the filter.The transmission in % is plotted on the vertical axis.The famous "H-Alpha" emission line of hydrogen. ![]() 400nm is deep blue, at 520nm the human eye senses green and at 600nm red. The horizontal axis is the Wavelength in Nanometers (nm).More information about the photographic Astronomik filters More information about the visual filters If you use a telescope larger than 8", you can try our O III filter for even better results when observing specific nebulae. If you use a telescope with an aperture larger than 5", we suggest the use of our standard UHC-filter because of its greater contrast enhancement capabilities. Photography under light-polluted skies with DSLRs and other cameras.As the UHC-E filter passes a spectral line of Carbon (due to the higher FWHM) it opens up the possibility of comet observation. It's therefore better suited to smaller telescopes. The contrast enhancement is less than that of the Astronomik UHC filter, but at the same time the transmitted amount of starlight is greater. Thus it increases contrast between your target and the night sky. ![]() sodium and mercury vapour) as well as airglow. The Astronomik UHC-E filter provides a FWHM of 45nm and blocks the light of typical streetlights (e.g. It is best suited for telescopes up to 5" / 125mm. The UHC-E Filter increases contrast of emission nebulae and comets and blocks the light of typical streetlights as well as airglow. It’s particularly suitable for small ’scopes. The most important lines are from ionised Hydrogen (H-alpha and H-beta) and double ionised oxygen (OIII).Astronomik UHC-E Filter Transmission CurveĬlick the image for full resolution The Astronomik UHC-E filter is our budget filter for deep-sky observation of emission nebulae and comets under light polluted skies.
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