CLS Filters
CLS Filters
CLS Filters
CLS Filters
CLS Filters
CLS Filters
CLS Filters
CLS Filters
CLS Filters
CLS Filters
CLS Filters
CLS Filters

Astronomik

CLS Filters

Regular price
$ 75.95
Sale price
$ 75.95
Unit price
per 

This item is out of stock but you can place an order now and we’ll ship when it becomes available.

Description

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.

Main use

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.

Astronomik filters are a valuable complement to your telescope optical equipment train. They are used worldwide by professionals and advanced amateurs because of their superior quality and our guarantee: Astronomik filters are correctly optimized for naked eye visual observation, each object will be viewed with maximum contrast through your eyepiece. The transmission curves of the filters are designed so that you gain maximum contrast and brightness while retaining the subtlest gradations in each object. Astronomik filter transmission curves are optimized for telescopes with an aperture ratio of f/4 to f/15.

Our selection of filters is so extensive that we have the correct filter for almost every instrument and every observing situation. Whether you are using a small instrument or a huge Dobsonian, whether under the light polluted skies of a sprawling metropolitan area, or are viewing from atop high mountains, Astronomik has the filter that will provide you the best possible visual image. Period.

Quality Characteristics of Astronomik filters:

  • Superior Substrate: Astronomik filters consist of a precision polished substrate on which the actual filter, in the form of very thin (dichroic) interference layers, is applied. Because of these high quality measures Astronomik filters will in no way reduce the performance of your optical system. And contrary to common experience with other manufacturers´ filters, with Astronomik filters stars remain fine needle points of light!
  • Coating: Astronomik filters consist of up to 130 layers deposited on top of the completely transparent carrier glass. These layers work as the actual filter and as an antireflective coating.
  • Durability: Astronomik filters are completely scratch resistant, and not sensitive to moisture, dew, or high humidity. With others’ filters, after a few years, you start to notice their filter is no longer up to its full capability. Not so with Astronomik filters which maintain their ‘brand new’ transmission specifications year after year.

And, because of Astronomik’s extraordinarily resistant coating technology, our filters come with a 10year warranty.

The difference between Visual and Photographic CCD Series Filters:

The human eye is not sensitive in the infrared range as are CCD imagers and photographic film. For this reason, our Visual Filters do not have integrated IR Blocking.

Astronomik filters are highquality accessories for visual observing which will significantly expand your observing opportunities. After many years of use your Astronomik filters will be an accessory which will be ready to give you the same joy you experienced many years earlier when they were new.

Now that’s an investment worth making!

 Specifications

Suitability

  • 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

Technical Data

  • 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
  • Since 2008 we do ship filters with a completely new design. Any kind of halo or strange reflection is a matter of past

    The table gives you a short Overview about the suitability of our filters for various applications:

    Filter/Ability

    UHC-E

    UHC

    CLS

    OIII

    Visual dark skies

    0

    ++

    +

    ++

    ++

    Visual urban

    +

    ++

    +

    ++

    --

    Film

    +

    0

    ++

    -

    -

    CCD

    +

     

     

     

    +

    DSLR (Original)

    +

    +

    +

    ++

    ++

    DSLR (Modified)

    +

    ++

    ++

    ++

    ++

    DSLR (MC)

    +

    +

    +

    +

    +

    Webcam/Video (Planets)

    --

    --

    --

    --

    --

    Webcam/Video (Deep Sky)

    ++

    +

    ++

    o

    --

     

    If you touch the symbols with the cursor, more information will be displayed.

    Legend:

    ++ The filter is excellent for this application, the dramatic better image!

    + The filter is good for this application, the much better image!

    o The filter is suitable for this application, the slightly better image!

    - The filter is usable for this application.

    -- The filter is not suitable for this application.

    Personal Upgrade Path

    Buy risk-free: When it’s time to trade up you’ll get the most value for your used gear.