Astronomik CLS Clip Filter for Sony Alpha 7 and Alpha 9 Cameras

Astronomik CLS Clip Filter for Sony Alpha 7 and Alpha 9 Cameras

The Astronomik CLS Clip-Filter for Sony Alpha 7 and Alpha 9 Cameras is used for deep-sky photography in slightly light-polluted areas and can be inserted into the not astro-modified camera body within seconds.

The Challenge:

Do you own a Sony Alpha digital camera for astro-imaging? Then you have surely encountered the following problems:

• Large filters for large camera lens objectives are very expensive.
• If you place a filter holder between your camera body and lens, you loose the ability to focus to infinity.
• For very fast (low f/ number) telescopes like the Vixen R200SS or the Takahashi "Epsilon" astrograph, a filter drawer or a filter wheel cannot be used since the distance to the corrector lenses would be changed.
• With long exposure times, your camera's sensor chip is exposed to more dust.

With the Astronomik Clip-Filter System you can take care of all of these problems at once!

The patented Astronomik Clip-Filters are made of black anodized aluminum and laser-cut on state-of-the-art machines. They can be inserted within seconds directly into the camera body. There are no changes necessary and all lens functions (focus, screen, image stabilization) remain operational!

The Clip-Filter System also acts as an outstanding dust shield, which prevents the possibility of dust settling on the sensor during long time exposure (The MC-Clear filter does not have a filter effect and only acts as a dust shield.)

Compatibility:

The Clip-Filter are successfully tested with the bodies Sony Alpha 7, 7r (Not 7r IV), 7s, and Alpha 9. (Astronomik will test other/future models and add them here.)

The manufacturer has made a short video that shows the installation and removal of the clip-filter for Sony Alpha as seen above.

The filters are not suitable for Sony alpha 3000 to 6500 or Sony alpha NEX cameras.

Filter transmission curve (see image above):

• The horizontal axis is the wavelength in nanometers (nm). 400 nm is deep blue, at 520 nm the human eye senses green and at 600 nm red. At 656 nm 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 ~510 nm 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 656 nm is 0% at night!
• Photographic filters: The grey line in the background shows the sensitivity of a typical CCD sensor.
• The most important artificial emission lines are shown in orange. The artificial 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), double ionized oxygen ([O III]) and ionized sulfur ([S II]). The square brackets indicate that these lines are forbidden.

The Astronomik CLS Clip-Filter is directly inserted into the camera body and is used for deep-sky photography in moderately light-polluted areas.

Highlights: