Astronomik OWB-CCD Typ 3

Astronomik OWB-CCD Typ 2 1,25" (M28.5)

Astronomik CLS EOS Clip-Filter
Astronomik OWB-CCD Typ 2 Transmission Curve

Click the image for full resolution

The OWB filter would usually not be designated as an "astronomical" filter. The intention is to enable converted DSLR cameras (without inbuilt IR-filter) in order to be used for 'terrestrial' photography.

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 OWB (Original White Balance) filter shifts the complete spectrum of a converted DSLR in such a manner that the camera will not be exclusively usable for astro-photography. Therefore the decision, which in former times had to be made, whether to 'victimize' a DSLR in order to exclusively use it for astronomical tasks or accept the lower sensitivity on the red end of the spectrum it is now a thing of the past and disencumber your purse, too.

The OWB EOS Clip filter fits in all APS-C sized series of cameras from Canon: 20D, 30D, 40D, 50D, 60D, 70D, 7D, 300D, 350D, 400D, 450D, 500D, 550D, 600D, 650D, 700D and it also works with the 1000D, 1100D and 100D..

Main use

DSLR cameras which have been converted for astronomical use by removing the inbuilt IR-filter or by substituting it with a filter with greater range for H-alpha, have a white balance that made them unable for 'terrestrial' purpose. The spectral sensitivity of the DSLR will be changed by an OWB-Filter to the former range. In other words: The OWB pretend to be the conventional built-in filter!

Other uses

  • None
How to read the chart
  • The horizontal axis is the Wavelength in Nanometers (nm). 400nm is deep blue, at 520nm the human eye senses green and at 600nm red. At 656nm is the famous "H-Alpha" emission line of hydrogen.
  • The transmission in % is plotted on the vertical axis.
  • The red line shows the transmission of the filter.
  • Visual filters: The grey line in the background shows the relative sensitivity of the human eye at night. The maximum is at ~510nm and drops to longer and shorter wavelengths. 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 656nm is 0% at night!
  • Photographic filters: The grey line in the background shows the sensitivity of a typical CCD sensor.
  • The most important artifical emission lines are shown in orange. The artifical light pollution is dominated by see mercury (Hg) and sodium (Na), which are used in nearly all streetlights.
  • The most important emission lines from nebulas are shown in green. The most important lines are from ionized Hydrogen (H-alpha and H-beta) and double ionized oyxgen (OIII).

The major emission lines of artifical light pollution:
| Hg 435,8nm | Hg 546,1nm | Hg 577,0nm | Hg 578,1nm |
| Na 589,0nm | Na 589,6nm | Na 615,4nm | Na 616,1nm |

The major emission lines of nebulas:
H-β 486,1nm | OIII 495,9nm | OIII 500,7nm | H-α 656,3nm


  • Visual observation (dark skies): Unsuitable
  • Visual observation (urban skies): Unsuitable
  • Film photography: Unsuitable
  • CCD photography: Unsuitable
  • DSLR photography (original): Unsuitable
  • DSLR photography (astro modified): Very good, achieves a standard white balance for 'terrestrial' photography
  • DSLR photography (MC modified): Very good, achieves a standard white balance for 'terrestrial' photography
  • Webcam / Video (Planets): Unsuitable
  • Webcam / Video (Deep Sky): Unsuitable

Technical Data

  • Special spectrum in order to adapt modified DSLR cameras (removed or substituted inbuilt IR-filter) to achieve standard colour space in digital imaging.
  • Parfocal with other Astronomik filters
  • Glass thickness: 1mm
  • Completely resistant against high humidity, scratches and aging effects
  • Diffraction limited, the filter will not reduce the optical performance of your telescope!
  • Astronomik filters are delivered in a high-quality, long lasting, filter box

The filter is available in the following sizes

Filter displayed products below by their features
  1. EOS Clip-Filter (1)

OWB CCD-Filter

  • Clip-Filter (EOS XL) with ASTRONOMIK OWB-CCD Typ III

    Clip-Filter (EOS XL) with ASTRONOMIK OWB-CCD Typ III

    excl. VAT (Non-EU): €150.42 incl. VAT (EU): €179.00

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