Contact Us
Your Cart

COVID-19 and STOCK Availability Info | All EU countries min order value £200 ex VAT | All account holders will need to reset their password in our new system. Thanks for your co-operation!

Free Shipping Available
UK mainland orders over £240
EU Shipping is Back
Minimum order value £200 ex VAT

Baader 2" Solar Continuum Filter (540nm)

Baader 2" Solar Continuum Filter (540nm)
-19 %
Baader 2" Solar Continuum Filter (540nm)
Ex Tax: £104.16
  • Stock: 2
  • Model: 2458391
  • Shipping Weight: 0.30kg
  • SKU: 2458391
  • GTIN: 4047825009388
  • MPN: 2458391

Baader 2" Solar Continuum Filter (540nm), optically polished

Can be used for observation and photography of Sunspots and granulations ONLY in conjunction with a Herschel wedge or Astro Solar Safety Film.
If you want to use this filter for visual observations as well as photography together with a ND=3.8 photographic Astro Solar Safety Film, then you would also have to use an UV/IR blocking filter for the safety of your eyes.

In addition, according to customer feedback, the above mentioned Baader UV/IR cut filter would also immensely improve contrast of the image when used together with this Solar continuum filter.

The sharpest and most contrasty images can be achieved with any decent quality refractor (either achromatic or apochromatic) as at such a narrow spectral range no refractor will suffer from chromatic aberration.

Please note, this filter must be used in conjunction with either a Herschel wedge or Astro Solar Safety film. A Herschel wedge  should only be used with a refractor telescope for observing the Sun as reflector telescopes will most likely be damaged by the heath. If you have a reflector telescope, you must use an Astro Solar Safety film (ND=5 for visual and ND=3.8 for photographic use) in front of the telescope tube.

Baader Planetarium Solar Continuum Filter - 2"

  • This Baader Planetarium Solar Continuum Filter comes in a fully-threaded 2" round cell.
  • Works in conjunction with a primary white light solar filter (or Herschel Wedge Prism) to show more granulation and sunspot detail!
  • The Baader Planetarium Solar Continuum Filter boosts contrast, cuts down on atmospheric disturbances but transmits at 540nm.
  • Good for both visual work as well as imaging, and even makes a good star test filter.
  • The Baader Planetarium Solar Continuum Filter cannot be used alone when looking at the Sun, or eye damage and equipment damage will occur. Must be used in conjunction with primary solar filter.

Baader Planetarium Solar Continuum Filter Features:

True Optical Quality: Baader glass substrates are of true optical quality. Most other filters are merely made from raw flame-polished, "optically flat", or sometimes a top quality commercially polished filter glass (fine for camera filters), resulting in wavefront deformations that damage image sharpness and contrast when used with telescopes. Baader Planetarium filters are made from striae-free substrates, and actually fine optically polished flat to within 1/4 wave p-v over the entire surface, plane parallel to within 30 seconds of arc! This important and unique custom step adds cost - but the result is a filter that maintains the full wavefront quality of the telescope without double images or ghosting, even at high magnifications. Critical to maintaining this level of flatness are Baader's carefully balanced coating designs, which prevent coating surface stresses from warping the substrate. Such high flatness enables Baader filters to be used far in front of the focal plane, ahead of star diagonals and digital cameras. They are particularly well suited for attachment to the nosepiece of the Maxbright Binocular Viewer (other manufacturer's filters must be used in pairs, attached to the eyepieces).

Filter Durability: Filter durability has always been a hallmark of Baader Planetarium. The multi-layer dielectric coatings are plasma-assisted and Ionbeam-hardened using the latest technology (the coatings are harder than the glass substrate itself!). Baader filters withstand repeated real-world exposure to the elements and physical cleaning. Users need not leave their precious filters dull and dust encrusted to avoid cleaning - Baader filters may be used and cleaned without fear. We have heard sad stories from owners of other simpler soft-coated dielectric filters, who have seen their coatings degrade from normal exposure to moisture, or wiped away from routine cleaning. Some manufacturers even resort to sandwiching their delicate coatings in between two layers of glass (and risking blurred double images as well as eventual degradation from the edges inward). Baader Filters will truly last a lifetime.

Stackability: Unlike other filters, Baader Planetarium filters are truly designed to be stacked and combined. This is possible due to the high optical quality and highly efficient anti-reflection multicoatings. The ability to combine filters opens up many exciting possibilities, permitting unique spectral characteristics unachievable with any single filter.

Special Filter Cell: Baader's special filter cell design offers unique features that enhance their reliability and usability. Though difficult to produce, the ultra-thin filter cell results in the maximum possible clear aperture, in order to minimize vignetting (1.25" Filter clear aperture is 27mm, 2" Filter aperture is 45mm). The special threading has been designed to fit a wide variety of eyepieces and accessories (there is significant variation between the 1.25" filter threading used by eyepiece and accessory manufacturers). The front 'crown' of the filter incorporates milled notches which make handling and threading the filter a more secure operation in the dark.


General Information
Weight in Kg0.3

Write a review

Please login or register to review