Adjust the brightness level of the Moon, Venus, and other bright objects with the Optolong Variable Polarizer. A standard Moon Filter is similar to a pair of sunglasses. They work fine, but sometimes the scene is too dark or too bright, and there’s not a lot you can do about it. A variable polarizing filter is much more flexible than a Moon filter. It allows you to set the percentage of attenuation by turning the top section of the two-piece filter. Simply attach the 2" threaded filter to a like-sized eyepiece or Astro accessory barrel, and then slowly rotate the top half of the filter—it turns 360°—to achieve the results you desire.

The Optolong Variable Polarizing Filter also works great to cut brightness when you are using your telescope for terrestrial observations or photography. If you have ever done photography through a SLR or DSLR camera, you may have already been introduced to the qualities of a polarizing filter, since it is a very popular accessory for polarizing the light and making the sky appear bluer. You will especially appreciate a polarizing filter when viewing over water or photographing a scene that includes a river or body of water. Simply turn the filter until you achieve the most glare-free results—you will really see the difference.

Optolong UV/IR Cut filter is designed for ultraviolet and infrared wavelength blocking to improve sharpness of the image as most of the optics are designed for the visible spectrum, because it’s very difficult to create a lens with the same focal point for the visible and IR spectrum.

It is used on a digital camera and the video, which do not have an IR protection filter toward an image sensor or were remodeled. This is important because unfiltered CCD and CMOS sensors are extremely susceptible to UV and IR rays just outside the visible spectrum that can have a very negative impact on image quality.

Main Use and Performance

Suitable for color CMOS and CCD cameras and modified DSLRs.

Use with monochrome CCD for astrophotography.

Available to assist in focusing.

Act as an outstanding dust shield, which prevents the possibility of dust settling on the lens during long time exposure.

WARNING: The filters of Optolong are not designed for sun observation. DO NOT LOOK AT THE SUN WITH OPTOLONG FILTER. You would be BLIND if you fail to observe the warning.

Dark Filter 1.25 inch

Our 1,25" (M28,5) filters fit perfectly in all 1,25" (M28,5) filter wheels of the brands ZWO, QHY, QSI, Starlight Xpress, SBIG, Moravian and Atik.

The orientation of the filter in the filter wheel does not matter. It does not change the optical performance.

Dark Filter 2 inch

Our 2" (M48) filters fit perfectly in all 2" (M48) filter wheels of the brands ZWO, QHY, QSI, Starlight Xpress, SBIG, Moravian and Atik.

The orientation of the filter in the filter wheel does not matter. It does not change the optical performance.

Dark filter 31mm

Our 31mm filters fit perfectly in all 31mm filter wheels of the brands ZWO, QHY, QSI, Starlight Xpress, SBIG, Moravian and Atik. The design with protective ring and blackened filter edges prevents stray light, the filters are mechanically protected and easier to handle.

The orientation of the filter in the filter wheel does not matter. It does not change the optical performance.

Dark filter 36mm

Our 36mm filters fit perfectly in all 36mm filter wheels of the brands ZWO, QHY, QSI, Starlight Xpress, SBIG, Moravian and Atik. The design with protective ring and blackened filter edges prevents stray light, the filters are mechanically protected and easier to handle.

The orientation of the filter in the filter wheel does not matter. It does not change the optical performance.

Astronomik now offers you a range of three different UV+IR blockers as Luminance filters. The different spectral window of each new Luminance filters is designed to tune your setup to get the sharpest image from any optical design and any camera.

The Luminance channel is probably the most important for a great final image! You want as much signal as possible so the filter should have the highest transmission possible with a wide spectral bandpass. This combination provides the greatest sensitivity and gives you the highest photon counts on your pixels. While the high transmission level is a great aspect of the new Astronomik Luminance filters, not all optical instruments or additional optical elements like correctors, field-flatteners or reducers, have perfect colour correction so it can be the width of the spectral band pass of  the Luminance filter that can cause problems. A band pass that is too wide will allow the transmission of incompletely focused light (Chromatic aberration), making stars appear soft or bloated. In such cases image processing can become difficult, so having a slightly narrowed spectral window in your Luminance filter can reduce or eliminate this damaging effect.

To give you all the tools to gather the best data possible we have expanded our line of Luminance filters: Now you can select a Luminance filter perfectly matched to the kind of telescope you use, to get the highest signal and sharpest image for the Luminance channel!
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 completely free of any 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 and in combination with the new Deep-Sky RGB filters, the L3 filter will minimise the problem of bluish halos around stars.

The transmission curve characteristics and coatings on the new Luminance filters have been designed and engineered in such a way that no halos or reflections will be visible. Even with bright stars in the field of view you will be able to reveal the faintest structures in nebulas or galaxies.

Like all Astronomik Filters, the new Luminance filters are made using an extremely durable and scratch resistant coating, deposited on the finest polished optical substrate, which is free of any striae or internal strains. All substrates are made to exactly the same thickness, so all of our filters are parfocal.

Additional note for observers working under light polluted skies:
If your observing site suffers from light pollution you should try to use our CLS-CCD as a replacement for the Luminance filter. The transmission curve of the CLS-CCD will give you approximately the same amount of energy in all three colour channels while blocking nearly all unwanted artifical light pollution. Customers who replaced the Lx filter with the CLS-CCD are amazed by the increased quality of their data. This small change gives you the opportunity to take much deeper images from your current observing site.

Astronomik now offers you a range of three different UV+IR blockers as Luminance filters. The different spectral window of each new Luminance filters is designed to tune your setup to get the sharpest image from any optical design and any camera.

The Luminance channel is probably the most important for a great final image! You want as much signal as possible so the filter should have the highest transmission possible with a wide spectral bandpass. This combination provides the greatest sensitivity and gives you the highest photon counts on your pixels. While the high transmission level is a great aspect of the new Astronomik Luminance filters, not all optical instruments or additional optical elements like correctors, field-flatteners or reducers, have perfect colour correction so it can be the width of the spectral band pass of  the Luminance filter that can cause problems. A band pass that is too wide will allow the transmission of incompletely focused light (Chromatic aberration), making stars appear soft or bloated. In such cases image processing can become difficult, so having a slightly narrowed spectral window in your Luminance filter can reduce or eliminate this damaging effect.

To give you all the tools to gather the best data possible we have expanded our line of Luminance filters: Now you can select a Luminance filter perfectly matched to the kind of telescope you use, to get the highest signal and sharpest image for the Luminance channel!
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 completely free of any 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 and in combination with the new Deep-Sky RGB filters, the L3 filter will minimise the problem of bluish halos around stars.

The transmission curve characteristics and coatings on the new Luminance filters have been designed and engineered in such a way that no halos or reflections will be visible. Even with bright stars in the field of view you will be able to reveal the faintest structures in nebulas or galaxies.

Like all Astronomik Filters, the new Luminance filters are made using an extremely durable and scratch resistant coating, deposited on the finest polished optical substrate, which is free of any striae or internal strains. All substrates are made to exactly the same thickness, so all of our filters are parfocal.

Additional note for observers working under light polluted skies:
If your observing site suffers from light pollution you should try to use our CLS-CCD as a replacement for the Luminance filter. The transmission curve of the CLS-CCD will give you approximately the same amount of energy in all three colour channels while blocking nearly all unwanted artifical light pollution. Customers who replaced the Lx filter with the CLS-CCD are amazed by the increased quality of their data. This small change gives you the opportunity to take much deeper images from your current observing site.

Astronomik now offers you a range of three different UV+IR blockers as Luminance filters. The different spectral window of each new Luminance filters is designed to tune your setup to get the sharpest image from any optical design and any camera.

The Luminance channel is probably the most important for a great final image! You want as much signal as possible so the filter should have the highest transmission possible with a wide spectral bandpass. This combination provides the greatest sensitivity and gives you the highest photon counts on your pixels. While the high transmission level is a great aspect of the new Astronomik Luminance filters, not all optical instruments or additional optical elements like correctors, field-flatteners or reducers, have perfect colour correction so it can be the width of the spectral band pass of  the Luminance filter that can cause problems. A band pass that is too wide will allow the transmission of incompletely focused light (Chromatic aberration), making stars appear soft or bloated. In such cases image processing can become difficult, so having a slightly narrowed spectral window in your Luminance filter can reduce or eliminate this damaging effect.

To give you all the tools to gather the best data possible we have expanded our line of Luminance filters: Now you can select a Luminance filter perfectly matched to the kind of telescope you use, to get the highest signal and sharpest image for the Luminance channel!
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 completely free of any 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 and in combination with the new Deep-Sky RGB filters, the L3 filter will minimise the problem of bluish halos around stars.

The transmission curve characteristics and coatings on the new Luminance filters have been designed and engineered in such a way that no halos or reflections will be visible. Even with bright stars in the field of view you will be able to reveal the faintest structures in nebulas or galaxies.

Like all Astronomik Filters, the new Luminance filters are made using an extremely durable and scratch resistant coating, deposited on the finest polished optical substrate, which is free of any striae or internal strains. All substrates are made to exactly the same thickness, so all of our filters are parfocal.

Additional note for observers working under light polluted skies:
If your observing site suffers from light pollution you should try to use our CLS-CCD as a replacement for the Luminance filter. The transmission curve of the CLS-CCD will give you approximately the same amount of energy in all three colour channels while blocking nearly all unwanted artifical light pollution. Customers who replaced the Lx filter with the CLS-CCD are amazed by the increased quality of their data. This small change gives you the opportunity to take much deeper images from your current observing site.