Baader AstroSolar: Silver/Gold-, Safety- & Foto-Film

W A R N I N G

Looking at or near the Sun will cause instant and irreversible damage to your eyes, including blindness. Eye damage is often painless, so there is no warning to the observer that damage has occurred until it is too late. Do not point a telescope or its viewfinder at or near the Sun. Do not look through a telescope or its viewfinder as it is moving.

The full aperture of any instrument that is pointed at the sun must be covered with a proper solar filter or filter/mask combination.

Children and Visitors should be supervised by an adult at all times when partaking in solar observation. Otherwise, keep solar equipment out of a child's and visitors reach to avoid accidental injury.

Please read all manuals before use!

Three different kinds of Baader AstroSolar® Solar filter films are available:

In the following we explain the differences in using these filters.

Baader AstroSolar® Silver/Gold-Film

Safe for visual solar observation at low magnification (only for solar viewer)

AstroSolar® Silver/Gold Film has been specially developed for visual solar observation at zero magnification for use with solar viewers. This film is only being used for production of Baaders Solar Viewers.

The optical density of Solar Viewer AstroSolar® Silver/Gold is OD 5.0. Baaders Solar Viewer are CE-certified and comply to the Norm EN ISO 12312-2:2015 – thus they are certified for a safe and direct view into the sun.

AstroSolar® Silver/Gold has no added treatments to attain fine-optical properties necessary for high magnification work. It is not suited to being used in combination with telescope, binoculars, spotting scopes or camera lenses.

Baader Planetarium producing AstroSolar® Silver Film for more than 25 years. In the year 1999, during the grand total eclipse over Europe, more than 20 million solar viewers equipped with this film were in use. For the great american solar eclipse in USA 2017 Baader now introduce the successor to the market: Solar Viewer AstroSolar® Silver/Gold, with eye-sided reflex-free material for an excellent viewing experience.

Why don’t Baader use this film for telescopes – a simple answer:

When using precision-grade AstroSolar® Safety Film for telescopes, perfect optical quality is most important. However – this film must be treated with great care since the metal and protective coatings applied onto both sides of the film are very similar in their technical properties to the reflective surface applied onto astronomical mirrors.

Since a Solar Viewer AstroSolar® Silver/Gold is used visually at zero magnification, the optical grade of the film is not of prime consideration. Instead it is most desirable to apply protective coatings of highest durability grade, to end up with a protective film of much higher resilience against inadverted rough handling. This is being achieved for AstroSolar® Silver/Gold Film with its metal hard coated layer applied onto one side of the film, making it scratch resistant without sacrificing in sharpness and without creating a double image of the Sun due to adding up several layers of dark and/or reflective film onto each other.

A single layer of AstroSolar® Silver/Gold Film provides a perfectly sharp and energy balanced solar image – including the ability of identifying large sunspots and without transmitting irresponsible amounts of infrared(heat) radiation as with simpler sooth-filled energy absorbent films which do not offer added IR-blocking by metal reflective coatings.

Due to the dual side metallization process designed for AstroSolar® Silver/Gold Film, the film remains safe for a straight look into the Sun, even in case the front side of the viewer would suffer a scratch or mild kind of abuse. Still every solar viewer must always get a thorough inspection by the user to detect possible damages due to wrong handling and must be discharded in case a defect would be visible.

Baader ®AstroSolar Safety-Film (OD 5.0)

Safe for solar observation at high magnification (for all optical instruments).

Safe for solar photography at high magnification (for all optical instruments).

The patened Baader AstroSolar® Safety Film 5.0 is being produced for visual and photographic solar observation at high magnification (with additional optics). AstroSolar® Safety Film is best suited for precision work with all astronomical telescopes and binoculars – just as well as for all photographic camera- and tele-lenses

When using AstroSolar® Safety Film 5.0 – mounted in front of your optics – you can image the Sun and safely look through the viewfinder of your camera (if it is through the objective!) – or you can directly look into the Sun with telescopes and binoculars at any suitable magnification.

The coating of AstroSolar® Safety Film 5.0 is subject to constant quality control. Its reflective property and security for solar observation through optical instruments is being tested repeatedly.

AstroSolar® Safety Film 5.0 reduces the intensity of solar radiation by 99,999% to a factor of 1 : 100 000 of the initial value. Multiple coating processes on both sides of the carrier film are adding up during production to result in a perfectly uniform filtering result and help in neutralizing the effect of microscopic pores in the coating hat plague conventional glass solar filters which are commonly only coated on one side of the glass.

One single layer of AstroSolar® Safety Film is perfectly apt to enable production of a safe solar-filter, suitable to supply highest contrast and sharpness in combination with your telescope or camera tele-lens. Baader Planetarium produce this diffraction limited filter material for more than 25 years.

Important note: The eye safety norm EN ISO 12312-2:2015 for naked eye solar viewers does not apply to front aperture filters, covering long-range optics. AstroSolar® Safety Film 5.0 is not authorized to be used for naked eye solar observation or production of solar viewers. For direct solar viewing without telescope, binocular or camera optics, inquire for Baaders EN ISO 12312-2:2015 certified eclipse shades equipped with AstroSolar® Silver/Gold Film.

Baader ®AstroSolar Foto-Film (OD 3.8)

NOT safe for visual solar observation at low/high magnification!

Only safe for digital solar photography at high magnification!

AstroSolar® Photo Film 3.8 is only intended to be used by well-experienced Astro-imagers. AstroSolar® Photo Film 3.8 is not intended to serve for protection during visual solar observation. Also PhotoFilm is not necessary for imaging the sun with camera- or tele-lenses, or in the prime focus of most telescopes. The resulting exposure time would be much too short, respectively the results would cause severely overexposed images. Instead, you can use AstroSolar® Safety Film 5.0 with a modern camera up to a focal ratio of ca. f/15 to f/20 – even at ISO 100.

AstroSolar® Photo Film 3.8 solely is used in conjunction with astronomical telescopes – and only in connection with fast digital video cameras. This combination is highly apt to capture finest solar surface detail and granulation at extremely high magnification – but enabling ultrashort exposure increments measured in milliseconds – in order to “freeze” atmospheric turbulence (lucky imaging technique). The results are quite outstanding.

Do not use AstroSolar® Photo Film 3.8 until you are convinced to having gained sufficient experience with the hazards of Solar videography while using regular AstroSolar® Safety Film 5.0.

PhotoFilm OD 3.8 consists of the same optically treated carrier film with just diffraction limited properties as Baaders AstroSolar® Safety Film with optical density 5.0. The density of the adjacent multiple coatings however has been reduced for Photo Film in a very controlled fashion. OD 3.8 constitutes the border line, to still offer an absolute minimum of eye safety, in case someone would handle with the film and – in spite of extensive care – would accidentally catch up a split second view of the intense solar energy near focus. Still every amount of precaution must be undertaken to avoid just this to happen.

Sadly AstroSolar® Photofilm OD 3.8 may not be used for visual solar observation – not even in combination with additional neutral density filters nor other filters of any kind. Reason being: none such filter combo has been tested by any licensed authority for eye safety. Surely such combinations may exist and they may produce magnificent and interesting views with sufficient reduction of solar energy across a safe enough spectral passband. However – as a manufacturer – Baader would be obliged to warrant for sufficient eye safety and provide safety evidence for an innumerable amount of possible filter combinations each having it´s own certification.
For this reason Baader Planetarium GmbH must leave it with the clear statement that they do not approve of any other use for AstroSolar® PhotoFilm than described above.

Many astronomical Oldhands have asked repeatedly in recent years to produce an even brighter version of PhotoFilm in order to achieve even shorter delivery times. Unfortunately today nobody could or should offer such a product with his mind in peace. Just 20 years ago Carl Zeiss could afford to offer single side coated (and pinhole prone) photographic glass filters stopped to OD 3.5 – and offer them without any excessive warnings nor safety measures for photographic use with slow emulsion based SLR-cameras. In the contrary – the only warning read: “pinholes are common in solar filters. If found objectionable opaque with sharp brush and black paint”. Modern times product safety regulations do not allow to offer so bright and single side coated solar filters anymore.