Astronomik OWB Typ 3 Clip-Filter for Nikon DSLR Cameras with Full Frame Size Sensor

Astronomik XL-Clip-Filter für Nikon Full Frame Bodies

Now Astronomik is ready to offer you XL-Clip Filters for the full format bodies from Nikon:

The filters are held in place save and secure with no stress to the high quality glass. Mounting and dismounting is easy with your fingers, without tools! No changes to the camera are necessary for using the filters!

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.

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 Challenge:

Do you own a Nikon 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 you can take care of all of these problems at once!

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

The Clip-Filters are designed and optimized to be used with normal lenses and with telescopes as well. The Clip-Filter also acts as an outstanding dust shield, which prevents the possibility of dust settling on the sensor during long time exposure. The MC-Klarglas has no filter effect at all and is therefore actually only used as dust protection.

Due to the very tight Nikon bajonett the clip-filters add a minimal obstruction at the edge of the field.

The Astronomik Clip Filter is registered as a utility model at the European Patent Office.

Compatibility:

♦ The Nikon XL-Clip Filter have been successfully tested with the D750, D800, D810 and the D850.
♦ For the D850, you can only use manual focus lenses or a T-adapter (with a telescope). With AF lenses you will get an error message and the camera will not work! Workaround for this: You can apply some tape over the lens contacts and the camera will work fine with the XL-Clip Filter installed.
♦ Other bodies have not been tested by Astronomik yet.
♦ The Nikon XL-Clip will not work with cameras with APS-C sized sensors and not with the new mirrorless body. Clip-Filter for the APS-C sized models will be released in the near future.

Explanation of the filter transmission curve:

♦ 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 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), double ionized oyxgen ([O III]) and ionized sulfur ([S II]). The square brackets indicate that these lines are forbidden.

A short guide selecting the right filter for you

Lots of customers are overwhelmed by the vast number of filters offered by Astronomik. Due to that they give you a short guide how to select the right filter for your application below:

Astronomik´s normal recommendation for the "First Filter" is the CLS filter. The CLS blocks all unwanted artifical light pollution and natural airglow and gives you a dark background in your images. When using this filter you may expose much longer than without, so you will be able to pick much fainter structures and objects. The filter is designed in such a way that all objects are given in their natural colors - they would look the same if your human eye would be much more sensitive!

The CLS is the fist choice for any applications like Night-scape photography and Time Lapse movies!

Important: The standard CLS has no built-in IR-blocker. In case your camera has been modified for Astrophotography, please take the CLS-CCD which has a built-in IR-blocker!

If you have to work under a heavy light polluted sky, the UHC is a good choice too. Its transmission curve is very tight. It gives you the light from the Hß, [O III], Hα and [S II] lines in one single exposure. The reduction of light pollution is much stronger than the CLS/CLS-CCD, but the filter will work for gas nebulas only - any galaxies and open or globular clusters are filtered out! You will get "false colors" with the UHC, not natural colors like with the CLS/CLS-CCD.

The UHC-E has a more broadband light transmission. Here stars are less strongly suppressed, helpful for nebulae with star clusters.

If you want to die deeper into astrophotography, you should think about emission line filters centered on OIII, H-alpha and SII, available either with 12 nm or even 6 nm bandwidth. With these filters you can do ultra-deep images even under the worst sky you can imagine plus the full moon high up in the sky. The emission line filters isolate the light from a very tight range of wavelengths, don´t get any color information. If you want to create color images (false color like images from the HST), you will need all three filters to mix the three channels into a final color image.

When using DSLR cameras without IR cut filter in astronomy, we recommend the UV-IR block filters of the L-1, L-2 and L-3 series to correct chromatic aberrations when using refractive optics (camera lenses, refractors). Depending on the color correction of your scope you may use a wider spectral window for the Luminance data. The L1 filter has the widest spectral window, the L2 is about the same as our current L-Filter and the L3 is much narrower.

If you use an optical system that is more or less free of chromatic aberration you should get an L1 filter for your setup. For general use the L2 filter is well suited to most optical systems with a corrector, flattener or reducer in the optical train while the L3 filter is designed for users of refractors with a less-than-perfect color correction.

As protection against dust in DSLR cameras without IR cut filter, the MC clear glass filter is suitable. It blocks neither visible light nor UV or IR, but is parfocal with the other clip filters for Nikon full format cameras.

Especially made for planetary imaging are the ProPlanet IR pass filters. The IR light transmitted by them is less sensitive to air turbulence ("seeing"), which makes the images sharper, with increasingly longer wavelengths being increasingly less affected.

♦ 1 filter in plastic box