Astronomik OIII 6nm - CCD Filter, Clip Filter EOS XL
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
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
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.
Due to the new MFR coating technique you may use one single
filter on all instruments up to f/4 without a significant reduction in
Der Astronomik H-alpha filter MUST NOT BE USED for solar observation!Imaging with Narrowband-Emissionline Filters
you have to observe from light polluted sites (like most of us...),
imaging with Narrowband-Emissionline filters is the best way to take
great images, as all kind of light pollution can be blocked very
effective! Normaly an H-alpha filter should be your first step into this
amazing field of astrophotography! With an Narrowband H-alpha filter
you will be able to take deep and contrasty images even wih very heavy
light pollution or with the full moon high up in the sky!
look at other astrophotos, an H-alpha is the best choice for all nebulas
glowing red! An OIII filters expands your imaging possibilities, as you
are able to image all greenish/blueish structures. Planetary nebulas
and star forming regions are great targets! The SII filters completes
your HSO-set of filters. With these three filters you are able to
process your images like the ones from the Hubble space telescope!
The h-beta filter is not available in a 6nm version, as this filter has
nearly no meaningfull application. To illustrate this, there are two
images shown below: Both were taken with a unmodified Canon 650D. Even
as the camera has a sensitivity of less than 10% at H-alpha, there is
some signal und structure in the h-alpha image, while you cannot see
anything on the image taken with an H-beta filter!
Operation of the filter:
The filter blocks all
unwanted light from artifical light-pollution, natural airglow and
moonlight. Especially light from High- and Low-Pressure Sodium and
mercury lights and all lines of natural airglow are 100% blocked. The
filter increases the contrast between the sky-background and objects
glowing at the OIII line at 501nm.
Tipps and Hints for more applications:
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
The Astronomik 6 nm OIII CCD filter Clip Filter EOS XL is an extremely narrow emission-line filter for CCD photography