Astronomik Filters OIII 6nm CCD 50x50mm Ungefasst

The OIII-CCD Filter is suitable for imaging of OIII nebulas from observation sites with light pollution and from dark sites as well. The contrast between an object glowing at 501nm and the background is increased enormous!

Due to the combination of the narrow bandwidth of 6nm and the high transmission of typically 96% the filter gives you an enormous contrast boost, as all unwanted light from other wavelengths than is blocked form UV up to the IR. This results in an extremly dark background.

The FWHM of 6nm is matched to give you optimal performance with CCD and CMOS sensors with a very low dark current! The 6nm filter is the best choice if you are observing from a heavily light polluted site or if you are imaging faint objects in starcrowded regions of the milkyway.

Der Astronomik H-alpha filter MUST NOT BE USED for solar observation!

Features:

• perfect blocking of unwanted light from UV up to the IR
• parfokal with all Astronomik filters
• Not sensitive to moisture, scratch resistant, not aging
• opticaly polished substrate, striae-free and free of residual stresses
• High quality storage box

Using the OIII-CCD filter together with H-alpha-CCD and SII-CCD filters you make produce false-color emission line images (HSO) in the same way as the Hubble-Space telescope. This is possible even from heavyly light polluted sites!

In contrast to purely visual filters, photographic CCD filters have built-in IR-blocking, which prevents the optical problems caused by infrared radiation.

MRF-coating: thanks to the new MFRF coating technology, it is possible to use the filter on all devices up to an aperture of f/4.

Alternative: The line filters with 12nm full width at half maximum are interesting if you are using a DSLR or a CCD camera with a higher dark current. The 12nm filters are also the best choice if your camera has a built-in guiding chip, because when using the 12nm filter you typically have twice as many stars in the image.

A bit of help with your selection:

• As a first filter, we recommend the Astronomik CLS filter. This filter suppresses artificial light pollution and natural airglow. By using this filter you get a dark-sky background and can therefore use much longer exposure times to make fainter objects visible. The filter is optimised in such a way that objects are reproduced in their natural colours. Important: the simple CLS filter has no built-in IR-blocking. Therefore you will need the CLS-CCD filter for an astro-modified camera!
• A good choice for working in locations with really heavy light pollution is the Astronomik UHC filter. The transmission curve of this filter only allows the light of the H-beta, OIII, H-alpha and SII lines to pass through. The background suppression is significantly stronger than with the CLS, however this filter works only for gas nebulae! Star clusters and galaxies are largely filtered out.
• For a more in-depth introduction to astrophotography, we recommend the OIII, H-alpha and SII emission lines filters, available with full width at half maximum of 6nm or 12nm. With these filters you can create detailed images of faint objects even from locations with extreme light pollution and a full Moon high above in the sky. Images in these narrow emission lines are not naturally coloured.
• For the owners of astro-modified cameras we offer the Astronomik OWB filter: OWB stands for “original white balance”. The filter corrects the displaced colour reproduction of a converted camera so that it can also be used for normal every-day photography, without having to revise every image on the computer.