Astronomik CLS Light Pollution Filter - Canon EOS Full Frame XL Clip
The Astronomik CLS is a budget filter for visual observation, Black & White photography and CCD photographs of nebulae, galaxies and star clusters with astronomical instruments of any size.
The Astronomik CLS blocks the light of the spectral lines of mercury and sodium-vapor lamps and lets the largest part of the visible light and H-alpha emissions pass. All the important emission lines, as well as the spectral region that the very well dark adapted eye can see, can pass through the filter.
The filters are optimized for use with aperture ratios from 1:3 to 1:15. Transmission losses and chromatic distortions, which are problems with other filters, only appear with Astronomik filters when extremely bright aperture ratios of 1:2 and more are used. The CLS filter is suitable for use with telescopes of all aperture sizes and even works well with binoculars.
The Astronomik CLS Light Pollution Filter is good for use under both dark and urban skies for reducing light pollution made by mercury-vapor lamps. For film photography and modified DLSR use, the CLS filter gives good performance and near perfect color balance. While this filter does perform well with webcam and video equipment under light polluted skies, it is not suitable for planetary use.
- Visual observation (dark skies): Good, to reduce light pollution by mercury-vapour lamps (streetlight)
- Visual observation (urban skies): Good, an UHC-E or UHC filter is more suitable
- Film photography: Very good, colour balance is near perfect CCD photography: Good, when used with an additional IR-block-filter
- DSLR photography (original): Good, colour balance shifted but contrast enhanced
- DSLR photography (astro modified): Very good, colour balance is near perfect
- DSLR photography (MC modified): Good, when used with an additional IR-block-filter
- Webcam / Video (Planets): Unsuitable
- Webcam / Video (Deep Sky): Very good, if light pollution is a big problem
About the Astronomik XL Clip-Filter System....
The patented Astronomik Clip-Filter System for Canon full-frame cameras is black anodized aluminum and laser-cut on state-of-the-art modern machines. It can be inserted within seconds directly into any full-frame (5D and 6D, for example) EOS camera body. There are no changes necessary and all lens functions (focus, screen, image stabilization) remain functional! If you have a EOS Rebel, or other Canon APS-C sized camera body, you should purchase the standard-sized Astronomik CLS EOS Clip filter instead.
Almost all Canon system lenses (with the exception of the EF-S series) and all M42 and T2 lens adapters, can be used with the Astronomik Clip-Filter System. 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.)
Astronomik CLS Light Pollution Filter - Canon EOS Clip Features.
- 92% transmission at 486nm (H-beta)
- 92% transmission at 496nm (OIII)
- 92% transmission at 501nm (OIII)
- 97% transmission at 656nm (H alpha)
- Pass from 450 to 540nm and beyond 650nm
- Parfocal with other Astronomik filters
- Glass thickness: 1mm
- Completely resistant against high humidity, scratches and aging effects
- Diffraction limited, the filter will not reduce the optical performance of your telescope!
- Astronomik filters are delivered in a high-quality, long lasting, filter box
- Additional Information
SKU AK-CLS-EOSXL Manufacturer Astronomik Type of Filter Light Pollution Reduction Filter Usage Imaging Single or Set? Single Filter Filter Size EOS Full Format Filter Shape EOS XL Filter Mounted? Mounted Warranty 10 Year Warranty
Customer Reviews 1 item(s)
- Great for LP regions, with a caveat
I originally started astrophotography with my Canon EOS 7D and Canon EF 600mm f/4 L II lens. The combo was a great start, the fast aperture worked well with the 7D to lift the red channel above the noise floor. I started right off the bad with the Astronomik CLS for EOS APS-C cameras, and the experience was wonderful.
I recently added a 5D III to my collection of DSLRs, and decided to stick with the CLS for an LP filter. In terms of function, the Astronomik CLS-XL for FF Canon DSLRs works the same as the one or APS-C. Clipping the filter in is a little more difficult, as it requires locking the mirror up, and it stays up until you remove the filter.
There is one caveat to using this particular filter that is rather frustrating. The way it is designed, the filter is clamped into a small metal holding frame in such a way that the holding frame actually adds a significant amount of vignetting at the top and bottom of the frame. I leave the filter in when I take my flats, however even when doing that, the flats are insufficient to fully combat the vignetting problem. This is rather disappointing, as it effectively forces you to lose some of the frame area benefit of the 5D III (or, for that matter, any Canon FF DSLR). I always have to crop the top and bottom, and to some degree the left and right edges.
I would recommend to Astronomik that they redesign the FF Canon EOS CLS clip-in filter to eliminate the vignetting. Find a way to attach the filter to the holding frame in such a way that it does not require the frame to actually wrap around into the light path. I intend to continue using the filter, as without, LP causes my background sky to increase at much too fast a rate, and my exposure times are severely limited (which poses a real problem for exposing the red channel deeply enough to separate it from the left edge of the histogram and lift it above the noise floor.)
I am happy to be able to use an effective LP filter with my DSLR. It definitely blocks out a LOT of LP, and despite the rumors, calibrating nebula and background sky color in post is pretty easy. Star color suffers very slightly (much like using an Ha nd OIII filter), however that hasn't been a major issue for me when it comes to my nebula photography. Frankly, though, I am a bit bummed that this filter cost $200 when it has such a severe vignetting issue. I truly believe Astronomik should address the issue and release a revamped version of the product, especially with the Canon EOS 6D becoming a popular astro-modded full-frame model!
1= Houston, We Have a Problem & 5= It's Out of This World
- Included Items
- Astronomik CLS Light Pollution Filter Clip for Canon EOS Full Frame Cameras
- Plastic Storage Case
- Questions & Answers
Product QuestionsQuestion by: Vichakorn on Dec 23, 2016 6:19:00 PMThis filter is generally not recommended for lenses with a focal length of less than around 50mm focal length. The angle of incidence in wider lenses can lead to banding artifacts similar to polarizing filters as the passbands shift with the incoming angle of light.Answer by: Chris Hendren (Admin) on Dec 27, 2016 11:32:00 AM
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