TS-Optics 1.25" Premium UHC Nebula Filter against stray light - more contrast in emission nebulae
This filter suppresses disturbing artificial light and thus improves the visibility of nebulae that emit light themselves - also in photography.
The problem: An ocean of city lights causes a large amount of background illumination that drastically reduces the visibility of space objects. This is the case everywhere but in the most remote rural areas. As a result of this you can see much less of an objects and much fewer objects than would be possible with your telescope.
The solution: Fortunately, many celestial objects, namely emission nebulae, shine in other parts of the spectrum than our artificial lighting.
This is where the TS Optics UHC filter comes into play: It allows these important wavelengths to pass through, while the rest of the spectrum is almost completely reflected. This reduces stray light to a fraction of its normal brightness, while the light from celestial objects can pass almost unhindered. This increases the contrast during observation, moving hundreds of additional objects within reach of your telescope.
With which objects does the filter work - and how well?
In the area where the filter is transparent, planetary nebulae ([O III] lines) and many diffuse emission nebulae (H-beta line) radiate.
Diffuse emission nebulae like the Orion Nebula are gigantic accumulations of hydrogen, in most cases also oxygen and partly sulfur, millions of times heavier than our sun! New stars are often formed here from the gases mentioned above, with hydrogen being the most important, even if the H-beta-line visible to the eye does not usually appear too strong. Fortunately, oxygen has been produced earlier in the history of the universe, whose light can now be seen. In the mentioned Orion Nebula both hydrogen and oxygen are important for its appearance.
Planetary nebulae like the Dumbbell Nebula are the remains of old stars that are at the end of their lives - hurled away star atmospheres, enriched with heavier elements like oxygen. By the way, the name comes from the round shape that many of these objects show in the telescope.
To simulate the effect of the filter, we chose the Dumbbell Nebula because it is easy to find and observe even in small amateur instruments:
This is how the Dumbbell Nebula M27 looks like in a medium-sized telescope when observed from a small town
And this is how it looks like when observed through a TS-Optics UHC filter under otherwise identical conditions. You can see much more structures here than without filter!
(Unfortunately it is not possible to show the visual effect on a real photo since cameras perceive celestial objects differently. For this reason we have simulated the effect by digital image processing. The image was made to resemble the true impression as closely as possible and to the best of our knowledge).
The filter works with the following telescopes:
The UHC filter can be used with any telescope which allows using 1.25" eyepieces. The filter will work well with any telescope from 70 mm aperture.
Tip from Teleskop-Service: Most telescopes with 2" eyepieces also include a reduction to 1.25" with integrated 2" filter thread. If you insert a 2" filter here, you don´t need to change the filter from one eyepiece to the other when you change the magnification.
Can the filter also be used beneficially in astrophotography?
Yes, because the most important lines H-beta and [S II], which cannot be observed visually at night because of their position in the red region of the spectrum, are also passed. However, a camera must be sensitive in this range and infrared radiation must be blocked if necessary.
