Astronomik City Light Supression / Light Pollution Reduction CLS Filter - 36mm Round Unmounted
Ships by Next Business Day
Contiguous US Customers:
All items we sell ship for free within the Contiguous US. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. During checkout, you may also be shown other optional faster shipping choices.
US Customers in Hawaii and Alaska:
Free shipping applies to almost all products. A few large telescopes and mounts are excluded from this free shipping offer. For these items, please contact us to obtain a shipping quote before you check out using the online shopping cart.
International Customers:
Free shipping does not apply to international orders. During check-out, you will be presented with several shipping choices and costs. However, the export of some items may be restricted outside the US due to size or manufacturer restrictions.
The Astronomik CLS filter is designed for visual observation and photography of nebulae, galaxies, and star clusters using telescopes and lenses. It completely blocks the emission lines from high- and low-pressure sodium (Na) and mercury (Hg) vapor lamps, as well as all lines of natural airglow, while allowing the majority of visible light and nebulae emissions to pass through. This enhances the contrast between deep-sky objects and the night sky, making it ideal for photography and observation in light-polluted areas.
Due to its wide passband, the Astronomik CLS filter passes a substantial amount of light, minimally dimming stars. The filter is designed to block as much unwanted light as possible while still transmitting the maximum amount of light from astronomical objects.
Other uses
The 1.25" and 2" socket models can be used for observations from light-polluted areas.
Alternatives
If there is no built-in IR cut filter in your camera, an Astronomik CLS CCD filter is required.
Suitability of the Astronomik CLS filters
- CMOS and CCD photography: Good, requires an additional Astronomik IR-Block filter
- DSLR photography (original): Good, color balance is shifted but contrast is enhanced
- DSLR photography (astro-modified): Very good, color balance is close to perfect
- DSLR photography (MC-modified): Good, requires an additional Astronomik IR-Block filter
Size of filter
Astronomik filters come in a wide range of standard sizes, both mounted and unmounted, to suit various optical setups and cameras. This version is a filter with protective ring for filter wheels without screw thread. The glass thickness is 1mm, the mechanical thickness is 3mm, and the diameter is 36mm.
Technical Data
- 92% transmission at 486nm (H-beta)
- 92% transmission at 496nm (OIII)
- 92% transmission at 501nm (OIII)
- 97% transmission at 656nm (H-alpha)
- Transmission range: 450 to 540nm and above 650nm
- Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)
- Finely polished optical glass, free of any striae, residual stresses, and bubbles
- Extremely scratch-resistant and durable coating
- Completely resistant against high humidity and aging effects
- Parfocal with other Astronomik filters
- Diffraction-limited
- Optimized spectral windows
- Delivered in a high-quality, long-lasting filter box
Due to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore effectively eliminated.
All Astronomik filters are ideal for modern cameras, including both CMOS- and CCD-based models, ensuring you capture the best possible images with your equipment. Sharpness, contrast, and the absence of any reflections and halos are guaranteed. Even with bright stars in the field of view, nebulae and galaxies will be captured with the finest structures. The Astronomik MFR coating is designed for optimal performance across a wide range of focal ratios of the optics used.
Every Astronomik filter undergoes a rigorous quality control process before delivery.
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Hide Found a better Shipped Price on Frontend? | No |
The Astronomik CLS filter is designed for visual observation and photography of nebulae, galaxies, and star clusters using telescopes and lenses. It completely blocks the emission lines from high- and low-pressure sodium (Na) and mercury (Hg) vapor lamps, as well as all lines of natural airglow, while allowing the majority of visible light and nebulae emissions to pass through. This enhances the contrast between deep-sky objects and the night sky, making it ideal for photography and observation in light-polluted areas.
Due to its wide passband, the Astronomik CLS filter passes a substantial amount of light, minimally dimming stars. The filter is designed to block as much unwanted light as possible while still transmitting the maximum amount of light from astronomical objects.
Other uses
The 1.25" and 2" socket models can be used for observations from light-polluted areas.
Alternatives
If there is no built-in IR cut filter in your camera, an Astronomik CLS CCD filter is required.
Suitability of the Astronomik CLS filters
- CMOS and CCD photography: Good, requires an additional Astronomik IR-Block filter
- DSLR photography (original): Good, color balance is shifted but contrast is enhanced
- DSLR photography (astro-modified): Very good, color balance is close to perfect
- DSLR photography (MC-modified): Good, requires an additional Astronomik IR-Block filter
Size of filter
Astronomik filters come in a wide range of standard sizes, both mounted and unmounted, to suit various optical setups and cameras. This version is a filter with protective ring for filter wheels without screw thread. The glass thickness is 1mm, the mechanical thickness is 3mm, and the diameter is 36mm.
Technical Data
- 92% transmission at 486nm (H-beta)
- 92% transmission at 496nm (OIII)
- 92% transmission at 501nm (OIII)
- 97% transmission at 656nm (H-alpha)
- Transmission range: 450 to 540nm and above 650nm
- Glass thickness: 1mm (except Astronomik OWB Type 3 and XT filters)
- Finely polished optical glass, free of any striae, residual stresses, and bubbles
- Extremely scratch-resistant and durable coating
- Completely resistant against high humidity and aging effects
- Parfocal with other Astronomik filters
- Diffraction-limited
- Optimized spectral windows
- Delivered in a high-quality, long-lasting filter box
Due to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore effectively eliminated.
All Astronomik filters are ideal for modern cameras, including both CMOS- and CCD-based models, ensuring you capture the best possible images with your equipment. Sharpness, contrast, and the absence of any reflections and halos are guaranteed. Even with bright stars in the field of view, nebulae and galaxies will be captured with the finest structures. The Astronomik MFR coating is designed for optimal performance across a wide range of focal ratios of the optics used.
Every Astronomik filter undergoes a rigorous quality control process before delivery.
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Hide Found a better Shipped Price on Frontend? | No |
Astronomik City Light Supression / Light Pollution Reduction CLS Filter - 36mm Round Unmounted