Telescopes Canada

Astronomik CLS CCD filters are suitable under light-polluted skies for DSLR Cameras which have been modified for astronomical use. For unmodified DSLRs, use Astronomik CLS filters.

The filter enhances the contrast between all deep-sky objects and the background.

The CLS-CCD Filter enhances the contrast between astronomical objects and the background. Due to the wider transmission curve compared to UHC filters, a greater amount of light will pass the filter. Stars will be less dimmed. This filter has been optimized to block as much spurious light as possible and simultaneously provide the best performance for 'useful' light. A good filter for DSLR-, CCD- and film b/w-photography as well as observation of deep-sky-objects with telescopes or photo lenses of all aperture f/3 and above.

Main use

The filter blocks completely emission lines of artificial light sources like streetlights (e.g. sodium- and mercury-vapor) as well as the airglow. All 'important' emission lines as well as the spectral range of the night-adapted eye are being passed. The supplementary IR-blocking layer allows the use for DSLR- and Webcams without an integrated IR-block filter.

Other uses

Easier resolution of Double Stars
With the EOS-Clip model, photography with DSLR cameras is feasible even under extreme light-polluting conditions without shifting the white balance.
The 1,25" and 2" socket models can be used for observations from light-polluted areas.
If you plan to create color images from emission line data, our CLS-CCD filter is a great choice for the Luminance channel
Alternatives
CLS: For cameras with an integrated IR-filter or for visual observation.

Suitability

Visual observation (dark skies): Good, to reduce light pollution by mercury-vapour lamps (streetlight)
Visual observation (urban skies): Reasonable, an UHC-E or UHC filter is more suitable
Film photography: Very good, colour balance is near perfect
CCD photography: Very good, optimized rejection of light pollution
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): Very good, colour balance is near perfect
Webcam / Video (Planets): Unsuitable
Webcam / Video (Deep Sky): Very good, if light pollution is a big problem

Sizes Available From Astronomik - Please ask us if we don't have a price listed for the one you would like

1.25" (M28.5)
2" (M48)
T-thread Cell (M42x0.75)
SC-Cell (2" / 24TPI)
Ø27mm
Ø31mm
Ø36mm
Ø42mm
Ø50mm
50x50mm
EOS APS-C Clip-Filter
EOS APS-C XT Clip-Filter
EOS M Clip-Filter
EOS XL Clip-Filter
Sony Alpha Clip-Filter
Nikon XL Clip-Filter
Pentax K Clip-Filter

Returns Policy

You may return most new, unopened items within 30 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

Items that have been opened, damaged or are otherwise unsaleable will be subject to a minimum 10% restocking fee, to be assessed by Telescopes Canada upon receipt of the returned goods

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the 'Complete Orders' link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Shipping

We can ship to virtually any address in the world. Note that there are restrictions on some products, and some products cannot be shipped to international destinations.

When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.

Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.

Typographical Errors and Order Cancellations

Telescopes Canada reserves the right to cancel an order due to an error in pricing by Telescopes Canada or one of our suppliers, equipment being no longer obtainable, or other events which are out of our control.

Client-Initiated Cancellations

Client-initiated order cancellations are accepted prior to delivery of the equipment to the customer, thereafter it is a return.

95% transmission at 486nm (H-beta)
95% transmission at 496nm (OIII)
95% transmission at 501nm (OIII)
97% transmission at 656nm (H-alpha)
pass from 450 to 520nm and from 640 to 690nm
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
Since 2008 we do ship filters with a completely new design. Any kind of halo or strange reflection is a matter of past