Shopping cart
is empty

Home > Filters > Nebulae filters > H-Alpha Filters > Astronomik > H-alpha 12nm > Astronomik 2" 12nm H-alpha CCD filter

Astronomik 2" 12nm H-alpha CCD filter

Product no.: 16752
Manufacturer: Astronomik

$ 330.00

incl. VAT
plus shipping costs

too expensive?

ready for shipping in 1-2 weeks + lead time
Astronomik 2" 12nm H-alpha CCD filter
Product description
Specifications
Customer reviews

Product description:

Astronomik H-alpha 12nm Filter

The Astronomik H-alpha filter is a narrow band filter for CCD photography. The filter lets the H-alpha light of emission nebulae pass and blocks nearly the whole remainder of the spectrum where the CCD is sensitive.

We have re-desgined all of our photographic filters. Since the end of 2008 we are shipping our new "Halo-Free" filters. read more...

The full width at half-maximum (FWHM) of 12nm is optimized for the use with common CCD cameras and allows the use of very fast optics. It should be noted that the filter has a transmission of up to 99%.

Another advantage of the 12nm filters is the availability of guiding stars for cameras with a built-in-autoguider (SBIG). If you use a very strong filter like our 6nm filter you often won’t find a usable guidestar.

The range of application extends from 1:2.8 to 1:15. Transmission losses and chromatic distortions, which arise with other filters, only occur with Astronomik filters when extremely bright aperture ratios of 1:2 and more come into play.

Main use

The Astronomik H-alpha-CCD (12nm version) increases the contrast between objects, in this case between the H-alpha emission line and the skyglow background. Our Astronomik H-alpha-CCD (12nm version) completely suppresses the emission lines of artificial lighting (mercury (Hg) and sodium (Na)) and skyglow.

How do I interpret these transmission curves?

  • the wavelength is plotted in nanometers on the horizontal axis. 400nm corresponds to deep blue, 520nm to green and at 600nm to red
  • transmission, in %, is plotted on the vertical axis
  • visual filters: The gray curve shows the relative sensitivity of the dark adapted human eye at night
  • photographic filters: The gray curve shows the relative sensitivity of a typical CCD sensor
  • orange: the main emission lines which contribute to artificial sky glow, e.g lines from mercury (Hg) and sodium (Na)
  • green: the most important emission lines from nebulae, such as the lines from hydrogen (H-alpha and H-beta) and the lines from oxygen (OIII)

17.10.2019
We ship worldwide
Currency
Service
Advice
Contact
Universe2Go