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AstroSolar
Safety Film Solar Filter Material
NEW!
>
Herschel Safety Wedge Solar Prism 2"
(and accessories)
>
Calcium K-Line Filter
, (1¼")
NEW!
>
Solar Continuum Filter
, (1¼"
and 2")
>
Solar Spectrum
H-Alpha Systems and Baader H-Alpha Accessories
New
Baader D-ERF!
♦
AstroSolar™ Safety Film, White Light Solar Filter
Material
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Baader AstroSolar™
Safety Film
(Patent pending
in all European States - voted for "Astro-Product of the Decade" in the
USA, and Sky and Telescope's Sept 2000 Review "A New Standard in
Solar Filters")
Baader Planetarium's AstroSolar™ Safety Film delivers white
light views of the Sun that are unmatched by any other objective solar
filter or material. The views through AstroSolar display fine
solar details, including fine penumbral detail, solar granulation, and
lighter colored faculae. The disk is set against a dark
background, free of the haze and scatter that is common in typical
'mylar' films or inexpensive glass filters. The performance of
AstroSolar is even more remarkable when considering its very low cost -
only $36 for telescopes up to 8". We even have sizes large enough
for producing full-aperture filters for very large telescopes (see the
huge 40" filter as shown above!). When combined with
Baader's tips for a
simple do-it-yourself filter mount,
anyone can construct a complete low cost - High Quality - white light
solar filter for any telescope.
It is possible to further improve the stability and
sharpness of the solar image through the use of the Baader
Solar Continuum Filter.
Views of granulation and faculae are particularly enhanced through the
use of this filter, in combination with AstroSolar. Users of
achromatic refractors will be particularly pleased with the performance
using this additional filter.
Optical quality:
For a full interferometric report on the optical quality of AstroSolar,
please click on this link:

AstroSolar and TurboFilm Interferometric Report
This highest precision film consistently
produces strehl ratios of 94 to 96 percent in interferometric tests -
thus it performs optically as well as a high quality Fluorite Triplet
Lens by Carl Zeiss (per interferometric test results). Baader even had a
hard time themselves seeing any difference in performance between
AstroSolar™ and 1/20 wave precision optical windows which they stocked
from Zeiss. Their stock of precision polished plates runs into tens of
thousands of $ - all stocked for the 1999 eclipse - but AstroSolar™ was
so good in fact, that these plates were hard to sell. Baader AstroSolar
Safety Film shows notably more sharpness and contrast than any
competitive objective filter we know of, especially including the
affordable Glass Objective Filters and Mylar filters. We have
found that only our own superb
Baader Herschel Safety Wedge is able to
noticeably exceed the performance of AstroSolar.
What is even more important - with AstroSolar™
the Sun appears in it' s real color - neutral white (with only a slight
bluish tinge). Other films and glass filters produce a blurry bluish or
reddish/orange/yellow Solar image, thereby cutting part of the spectrum.
Especially with an orange sun, it is very hard to see faculae regions
which are visible predominantly in the blue wing of the spectrum.
Due to it's neutral
color balance, AstroSolar enables the use of various color (or
interference) filters which allows the observer to concentrate on
certain spectral passbands for investigations of different layers within
the solar "atmosphere".
Eye safety:
AstroSolar™ is essentially free from pinholes, since - unlike even the
most expensive glass filters - it is coated on both sides, so that the
chance of two pinholes overlapping each other is extremely faint.
Pinholes do appear, but to 1 out of 10000 only, in optical density 2.5!
Baader AstroSolar™ safety film has been approved for eye safety by the
National Bureau of Standards in Germany, the PTB. Unlike any other Solar
Filter on the market, AstroSolar™ is CE-tested according to EG-Norm
89/686 and EN 169/92 ( notified body 0196). All processes connected to
this product have been thoroughly tested. Coatings are inspected
constantly for consistency to ensure your eye safety!
History and goal of
AstroSolar ™:
Baader Planetarium delivered solar safety film for 19 million eclipse
viewers that were used throughout Europe for the August 11 Eclipse. Not
one user of their films suffered from eye damage. Baader has produced
solar safety films for over 17 years and has reason to claim a high
degree of competence for all aspects of solar observation. With Baader
AstroSolar™ we are set out to show you the Sun' s hidden grandeur at a
fraction of the cost for comparable equipment. Real professional solar
work has typically been restricted to a few die hard amateurs who would
put up the $1000,- or more for a real precision 1/20 wave glass filter.
Now you can get an equally precise AstroSolar™ filter to fit an 8"
aperture for $36 (or much less even, if a whole group of people share a
larger roll of film). No longer will solar observation be a "ho hum"
experience, where you look into your telescope through an "economy
priced" glass or mylar filter and wonder what this kind of amateur
activity is all about. Many of our customers have pushed out the glass
or mylar from their older filters only to use their filter cell for
AstroSolar™ - and experience a completely new, crisp, and incredibly
esthetic sun. All of a sudden, the telescope has the same performance
during the day that it has at night, and now they realize that the
consistently 'poor seeing' at their site was really just a consistently
poor solar filter.. We are always amazed how easily some amateurs
accept mediocre sharpness during observation of our nearest star, while
they can be extremely critical if their telescope does not perform
perfect on other stars (or planets).
Production secrets /
products:
The development of AstroSolar™ was only possible due to the incredible
demand during the 1999 eclipse. Dozens of miles of film were destroyed
during tests to produce the tooling and process techniques to produce an
absolutely uniform molecular structure for the substrate. Not to speak
of the related treatments, annealing and dual side coating that the film
undergoes until it has attained the desired properties. As a result of
this material breakthrough, Baader is able to offer two film products
which do not at all distort the performance of your telescope;
1. AstroSolar™ for solar observation and photography,
2.
TurboFilm™ , an optically clear
precision film for night time protection of your valuable optical
equipment; to shield it against dirt, scratches, coating defects,
humidity inside open tubes and on mirror surfaces - and last not
least, to stop air currents (tube-seeing).
For construction of a simple do-it-yourself cell for
AstroSolar, please click on this link:
simple do-it-yourself filter mount
- Baader AstroSolar Safety Film, Visual (ND5), Small,
A4 Sheet (7.9"x11.8"), (#ASOLV-S)
- Baader AstroSolar Safety Film, Visual (ND5), Medium
Roll (39.4"x19.7"), (#ASOLV-M)
- Baader AstroSolar Safety Film, Visual (ND5),
Extra-Large Roll (46"x46"), (#ASOLV-L)
PRICING | ORDERING
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♦
Herschel Safety Wedge Solar Prism 2"
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Images taken with the Herschel Safety Wedge
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The
New Baader Planetarium
2" Herschel Safety Wedge Solar Prism offers the finest
white-light solar views obtainable, and is the only white light filter
that we have found to noticeably exceed the performance of Baader
AstroSolar Film. The Herschel wedge prism
provides safe full-aperture solar views without absolutely no image degradation.
Views are noticeably superior in resolution and contrast to even the
very finest and most expensive glass objective solar filters and films.
The amount of Sunspot detail and surface granulation will surprise even
the most experienced solar observer. Penumbra resolve into a
staggering range of contrasts and fine wispy details. The solar disc is set against
a jet-black sky, like observing the full moon at night! With our
Herschel Wedge Prism, it becomes obvious that the lack of detail and
contrast experienced with most other white-light filters was not so
much due to the atmospheric seeing as you had thought... A further
benefit is the true unfiltered nature of the spectrum passed by the
filter. Unlike all objective solar filters, the Baader Herschel
Wedge does not selectively filter any of the visual wavelengths.
This provides a true white-light view, and permits the use of additional
eyepiece filters to selectively study any bands desired, without the
compounding effects of a pre-filter.
The Baader Safety Herschel Wedge is
the finest solar wedge ever produced for amateur use. It is
the culmination of Baader's many years of experience in the design and production of Herschel
Wedges. Utilizing a precision 2"
genuine
Zeiss ultra-smooth wedge prism and proprietary Baader optical design
for stray light elimination, the Baader Safety Herschel Wedge maximizes
image contrast and sharpness. While other herschel wedges
use a low-quality Chinese or other generic glass wedge prism, the large
first-surface Zeiss produced prism has high surface quality and
smoothness over its entire surface which will not break down at
magnifications over 100x, permitting full-disc photography and imaging
with no resolution or contrast loss across the full field.
As supplied, a special precision
polished and coated Baader ND=3.0 filter is permanently pre-installed
within the wedge housing (it MUST be present for any and all
visual observation). This critical safety feature ensures that the
ND filter will always be present, with no chance of accidentally viewing
the unfiltered light as with some other herschel wedges. The genuine
Baader ND filters have been designed and produced specifically for
Herschel usage, and are the only ND filters ever to be produced with
both surfaces fineoptically polished and anti-reflection multicoated. These
additional steps provide the highest image quality across the entire
field, preventing any image breakdown and scattered light which are
inherent in standard ND filters.
The modular design of the Baader
Herschel Wedge incorporates a removable 2" nosepiece and Deluxe 2"
Clamping eyepiece holder (with integral brass clamp ring and dual clamp
screws). The threaded machined aluminum body permits attachment of a full range of
Baader accessories, as well as for close-coupling of cameras and Baader binoviewers. A full system chart can
be found by clicking this
More Info link.
NEW FEATURES:
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Our latest version incorporates an innovative Light Trap developed by
Baader Planetarium. This development takes the Herschel Wedge into
the 21st Century, by rendering the output energy cool and diffused!
In all other herschel designs, the waste energy is simply deflected out
of the rear face of the prism by an angled mirror. Though quite
safe with careful use, the user still had to be aware not to place any object (or
body part..) into
this output beam (and to prevent any casual onlooker from
carelessly staring up into the beam). Thanks to Baader
Planetarium, this concern has now been completely removed. In
place of the typical output mirror is a coated multi-layered
perforated steel screen. The bright light and heat energy are
harmlessly diffused. Even after prolonged observations through
large refractors, the light trap remains cool. You can even
place a hand below the output and no heat can be felt (also, no tempting
or hazardous bright output for careless eyes to see).
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Each Baader Safety Herschel Wedge now includes a pre-installed 2"
Solar Continuum Filter!
With the Solar Continuum, the contrast and image stability is further
enhanced in all telescopes. The combination of the Herschel Wedge
and Solar Continuum Filter delivers the finest solar views obtainable
with any white-light telescope. The Solar Continuum filter may be
removed by the user, if desired (but the ND=3.0 must not be removed).
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We now offer two versions of the Herschel Wedge: The lower priced
Version-V (visual) comes with the pre-installed ND=3.0/1:1000
(required for safe viewing), and a pre-installed 2" Solar Continuum
Filter. The Version-P (photographic) starts with the
Version-V and adds 3 additional Baader ND filters (ND1.8/1:64,
ND0.9/1:8,
ND0.6/1:4 ). The additional
ND filters are handy for further dimming the image by using in place of
the Continuum filter for white light viewing, or attaching to
eyepieces or a
T2-15 Reducer, and are
particularly useful for imaging. Please refer to the
More Info page for additional
information.
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All of the fine-optically polished
genuine Baader ND filters now incorporate special anti-reflection
multi-coatings, to further eliminate light scatter and ghosting for
maximum image contrast. The result is image quality unachievable
with any other ND filter.
Please Note:
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The Herschel Wedge is only recommended for use with refracting
telescopes, NOT Schmidt-Cassegrain, Maksutov, or any other
Reflecting Telescopes. This is a professional-quality white light (not
H-Alpha) solar filtration system, whose basic design concept has existed for
almost as long as the telescope itself. Like glass or mylar film
objective solar filters, it is completely safe if used properly and
common sense precautions always observed.
Please click on the
More Info
link for additional safety information.
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Similar in length to any 2" diagonal, the Baader Herschel Wedge
requires more back-focus than a 1.25" accessory. The path
length of the Herschel is 128mm,
as measured from it's front face to the top of the 2" eyepiece holder.
Since most 2" eyepieces have their field stops well below the main
eyepiece body, most telescopes will need less than 128mm of back focus
to accommodate the Herschel. Most telescopes with 2" focusers will
have no problem providing this amount of back-focus (in-travel).
However, some telescopes, such as many TeleVue refractors, provide
limited back-focus that may require a shorter path length for some
eyepieces. For these scopes the path length of the Herschel may be reduced to
108mm for 1.25" eyepieces by the attachment of a T2-27
adapter and
T2-08 1.25" Clicklock eyepiece clamp.
"I received the Herschel prism Tuesday afternoon. Thanks for
shipping it so securely. I have read the additional safety
information and I will be sure to check that the D=3.0 ND filter is
always installed correctly. I absolutely love the views through it with
my AP 4" f/10 . It is better than I expected. Thank you again."
Stan Jung
"I recently bought a Baader Herschel wedge from you and would like
you to know that I am 101% happy and contented with its performance,
optical quality, as well as fit and finish. I would unhesitatingly
recommend it to anyone interested in the finest available white light
solar filter. Several of the images I took with the wedge have already
been featured in
spaceweather.com ." John
Nassr, Philippines
- Baader Herschel Wedge Solar
Prism 2", (#HERSCH-V)
- Baader Herschel Wedge Solar
Prism 2", (#HERSCH-P)
MORE INFO
| PRICING | ORDERING
Herschel Wedge Accessories: Polarizing Filters
A particularly handy attribute of the Herschel Wedge is
it's partial polarizing effect on the solar image. This permits a
very convenient means of variably adjusting the image brightness, simply
by using a single polarizing filter between the Herschel and Eyepiece.
The filter/eyepiece combo can then be rotated, and the image is variably
dimmed. We use a Baader polarizer in our own observations, finding this very useful to easily
achieve the optimum
brightness for maximum visual contrast at any magnification.
We sell two sizes of Polarizing filters for visual use with the
Herschel (both are produced in Japan for Baader Planetarium). The 1¼" version can be
threaded onto an eyepiece directly. The 2" can, of course, be
attached to a 2" eyepiece. For the ultimate in convenience, we
recommend the 2" Polarizer attached to a
T2-15 (2"/1¼"
reducer). This allows you to conveniently switch between 1¼"
eyepieces without removing the filter, and still maintaining a close
position between the eyepiece and filter. Use of a T2-15 also gives you a very
convenient means of attaching and removing the Solar Continuum filter.
Please
Note: Polarizing filters are intended for visual use
and must only be used in conjunction with the existing internal
ND=3.0 filter. A polarizing filter does not provide sufficient
blocking by itself, nor is it able to block IR wavelengths as completely
as an ND filter.
- Baader Polarizing Filter, 1¼”
(#FPOL-1)
- Baader Polarizing Filter,
2” (#FPOL-2)
Herschel Wedge Accessories:
Adapter 2"/T-2 Filterholder T2-27
The Herschel Wedge housing incorporates internal 2"
threading on the output. As supplied, the Herschel Wedge includes
a 2" filter holder and 2" Eyepiece clamp on the output of the
wedge. The T2-27 2"/T-2 Filterholder may be used to convert the
output of the Herschel Wedge to an external T-2 thread. This
allows closer direct attachment of cameras,
T2-08 Clicklock Eyepiece Clamp 1¼”/T-2
, or Binoviewers (use a
T-2 Quick Change Ring
for the Baader MkV). Please Note: The
ND=3.0 filter supplied with the Herschel MUST be transferred to the
T2-27 for visual use (or other ND filters for photographic use)
- Adapter 2"e/T-2e,
2” (#T2-27)
PRICING | ORDERING
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♦
Calcium K-Line Filter
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 © M.
Weigand |
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The
New Baader Planetarium
Calcium K-Line Filter makes imaging of the sun in K-Line accessible to
anyone with a telescope and digital camera or webcam. Baader's
innovative double-stacked filter uses sophisticated coatings to produce a sharp
8nm wide bandpass, centered at 395nm. This bandpass provides ample
contrast for high-resolution imaging of super granulation, flares, and
other features that are prominent in CaK. Unlike small,
dedicated, and expensive CaK telescopes, the Baader K-Line filter works
with with your existing telescope - at a small fraction of the cost. The Baader CaK may be used with
virtually any telescope, of any aperture - Newtonian, SCT, Refractor,
etc.
The Baader K-Line Filter is simply
used just like any standard 1.25" thread-on eyepiece filter. It
may be attached to an eyepiece for projection imaging (see
Digital Photography for camera
projection adapters and Digital T-Rings), or directly to a
camera's nosepiece (ie,
T2-14) for prime-focus . In addition, an objective pre-filter must
be used at the telescope's entrance to reduce the energy that reaches
the filter. For this purpose, a 200mm x 290mm (8x11inch) sheet of
Baader's renowned AstroSolar Photo Film (Photo ND=3.8) is provided with
each K-Line filter. This material may be easily mounted to any
telescope using instructions provided (see
AstroSolar and TurboFilm Mounting ).
The
Herschel Safety Wedge Solar Prism
may also be used as the energy rejection filter (in place of the
AstroSolar Photo Film). This will provide the absolute highest
quality solar images possible in CaK.
Please
note: The Baader K-Line filter is intended Only for
imaging. It is not suitable for safe visual observation (the UV
levels may pose an eye safety risk from prolonged observations).
Due to the eye's low sensitivity and very poor resolving ability at
395nm, solar features in CaK are generally invisible for most observers
- even through multi-thousand dollar sub-angstrom dedicated CaK etalons
and telescopes. All of these instruments are intended
primarily for imaging.

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* Image Venus! *
In addition to imaging the sun in CaK, the Baader K-Line
filter opens up another exciting possibility - imaging of Venus!
The narrow bandpass @ 395nm enables imagers to record cloud structures,
with results similar to the dedicated Baader Venus Filter.
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© M. Weigand
- Baader K-Line Filter,
1.25"(including 200x290mm AstroSolar ND-3.8), (#CAK-1)
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♦
Solar Continuum Filter
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The new Baader Solar Continuum filter is designed to enhance the
visibility of solar granulation and sunspot details. By
transmitting a specific spectral region around 540nm, free of emission
and absorption lines, the Solar Continuum filter is able to boost
contrast and reduce the effects of atmospheric turbulence.
With the Solar Continuum filter in place, images snap to focus, and
granulation becomes regularly visible. Details at the limit of
visibility become easier to hold, and image motion reduced.
The Solar Continuum filter works well
in all types of telescopes, for both visual and imaging. Users of
SCTs and achromatic refractors will find it particularly beneficial, as
it completely excludes the red and blue wavelengths, and centers on the
peak visual wavelengths where the telescope optics are sharpest and free
from chromatic aberrations. For digital imaging, we also recommend
the Continuum filter be combined with our
UV/IR Cut Filter (to completely cut the defocused far
infrared wavelengths).
The Solar Continuum filter also
makes the perfect star test filter. It's narrow bandpass and
complete blockage of longer and shorter wavelengths make it superior to
standard green colored filters for testing refractors at their center
design wavelength (and peak visual wavelength). With this filter,
more accurate appraisals of optical quality can be made, without the
effects of spherochromatism or secondary color error. Due to
the narrow 10nm bandpass, star testing through the Solar Continuum
filter will require a bright test star.
As with all Baader Planetarium
Filters, the Solar Continuum possesses all the trademark Baader filter
qualities. Optical, Physical, and Mechanical quality are superb.
For a summary of filter features, please see the
Filters
page.
Please Note:
For safe use, the Solar Continuum filter must be
used in conjunction with a primary solar filter (ie, Herschel Wedge
Prism, or Baader AstroSolar Film). It must be placed After the
primary filter, and cannot be used alone, or permanent eye and equipment
damage will result.
Please click on the image below for a typical
transmission curve:
Solar Continuum Filter Transmission Curve
- Baader Solar Continuum Filter, 1¼”
(#FSOL-1)
- Baader Solar Continuum Filter,
2” (#FSOL-2)
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♦
Solar Spectrum H-Alpha
Systems and Baader Accessories
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We are
excited to offer a full selection of advanced products for H-Alpha Solar
Observation! These truly professional grade products
have been selected to deliver the absolute highest resolution and
contrast views of Hydrogen Alpha features. The views through this
equipment truly rival the best photographs. Surface and prominence
details become shockingly crisp and high contrast, able to withstand
high magnifications for detailed study of individual features. The
amount of detail visible through these narrowband rear-etalon systems
rivals the Moon in its variety and observability. Smaller
aperture objective-based systems deliver convenient full disk views for
quick looks, but at a heavy penalty in the resolution and contrast
needed to detect and study the rich H-alpha solar features in full
detail at high magnifications. As with our Herschel Wedge Prism,
it becomes obvious that the lack of detail and contrast in other systems
was not so much due to the atmospheric seeing as you had thought...
Another
surprise is the relative affordability of Solar Spectrum filters.
A completely configured SO-1 0.5A system with 85mm clear (and
unobstructed!) aperture costs about $2,600. Compared to the
wider band single or double stacked objective etalon systems, the Solar
Spectrum filters offer greatly improved performance at significantly
lower prices.
Solar Spectrum H-Alpha Filter Systems
Solar Spectrum produces what we have found to be the
ultimate in professional H-Alpha filter systems. These
rear-mounted etalons deliver high-quality narrowband filtration that can
be used with apertures from as small as 40mm up to 180mm! Unlike
front objective etalons, the aperture is not limited by the diameter of
the etalon. Every Solar Spectrum filter can be flexibly configured
to match any desired telescope and aperture desired. Each Solar
Spectrum filter system includes the rear mounted etalon assembly (which
includes an integrated thermoelectric heater/cooler),
temperature control box with digital temperature readout, and AC power
cable. The control box accepts 90-256 VAC 50/60Hz. For DC
use, any inexpensive inverter can be used. A complete system
consists of a Solar Spectrum Filter and Front-Mounted Energy Rejection
Filter. Telescopes with focal ratios faster than f/25 will also
require a telecentric lens to produce the required f/25 - f/30 beam.
Currently, Telecentric lenses are available in 2X and 4X amplifications.
Availability: Currently, we offer Solar Spectrum
filters on a special order basis. Typical delivery times range
from 12-18 weeks, depending on filter size and bandpass. Occasionally we will have
a system available from stock. Please contact us for
specifics. Narrower bandpasses available
on request (primarily for imaging use). Calcium K-Line and custom
filters are also available upon request.
Payment: Deposit of 50% required at time of
order, remainder due when filter is completed and ready to ship.
Payments by check or money order only (sorry, no paypal or credit cards
for Solar Spectrum Products).
Solar Observer Series 1: Our most cost
efficient system. 19mm clear aperture enables solar full disk
views with focal lengths below 2000mm (60-80mm aperture). Of
course, larger telescope apertures may be used to deliver increasingly
detailed views. Available in the following bandpasses -
0.65A, 0.5A, <0.3A.
- Solar Observer 1, 0.65A +/- 0.05 Bandpass (#SS-SO1.65)
- Solar Observer 1, 0.5A +/- 0.05 Bandpass (#SS-SO1.5)
- Solar Observer 1, <0.3A Bandpass (#SS-SO1.3)
Solar Observer Series 1.5: Larger 25mm clear
aperture enables solar full disk views with focal lengths below 2400mm
(80-95mm aperture). Of course, larger telescope apertures may be
used to deliver increasingly detailed views. Available in the
following bandpasses - 0.65A, 0.5A, <0.3A.
- Solar Observer 1.5, 0.5A +/- 0.05 Bandpass (#SS-SO15.5)
- Solar Observer 1.5, <0.3A Bandpass (#SS-SO15.3)
Advanced Solar Observer: Large 32mm clear
aperture, enables visual use with 2" eyepieces and larger format
imaging. Enables full disk views with focal lengths below
3000mm. Available in the following bandpasses - 0.8A, 0.65A, 0.5A, <0.3A.
- Advanced Solar Observer, 0.5A +/- 0.05 Bandpass (#SS-ASO1.5)
- Advanced Solar Observer, <0.3A Bandpass (#SS-ASO1.3)
Research Grade Solar Observer: 32mm clear
aperture, extreme filter uniformity for research applications.
Available in the following bandpasses - 0.5A, 0.3A, 0.2A.
"I used the solar filter today. WOW!!!!!!
The level of detail is incredible. Using a Televue Panoptic 35 I
can see the entire disk. Using a BinoViewer with 26mm Meade
eyepieces, the field of view is smaller but the image looks almost 3D
and is far more pleasing. I am more than satisfied with this
equipment. Well worth the cost and the wait." Tony
Van Heugten (SO-1.5, 0.3A on a Meade 10" SCT with 90 C-ERF)
Baader D-ERF, Energy Rejection Filters
Baader planetarium has introduced a new evolution in
their premium
energy rejection filters, from 70mm up to 180mm! These filters
incorporate a new all-dielectric IR rejection coating that eliminates the heating from
IR energy to produce a truly cold focus (hence, "Cool ERF"). As a
result, the telescope and etalon remain cool and safe from excessive
heating. The result is longer filter life, and freedom from
tube currents caused by heating. Users with compound telescopes
(SCTs, Cassegrains, Maks) will really appreciate the D-ERF, due to its
reduced heat load on the mirrors and the reduction in tube currents
caused by internal heating.
Unlike every other ERF filter produced up till now, the
Baader D-ERF are produced from a high quality optical clear glass,
ensuring freedom from the internal impurities that caused so much
headache in producing the older red-glass ERFs. The energy
rejection is now accomplished using ultra-hard dielectric coatings on both sides of the
glass
substrate, and also serve to protect the glass, making it highly
resistant to scratches. Filters are polished plane-parallel,
smooth, and flat to an amazing 1/10 wave p-v over the entire surface.
The special dielectric filter stacks are precisely balanced to maintain
the superb optical flatness after coating.
For further information, please see:
D-ERF
Use
(150 kB)
D-ERF filters are sold un-mounted and are available in
the following diameters: 70mm, 90mm, 110mm, 135mm, 160mm, 180mm.
We occasionally have a limited stock in the smaller sizes (larger
sizes on request). Please contact us for further specifics and
availability.
- Baader D-ERF, 70mm Diameter (unmounted) (#DERF-70)
- Baader D-ERF, 90mm Diameter (unmounted) (#DERF-90)
- Baader D-ERF, 110mm Diameter (unmounted) (#DERF-110)
Please Note: Custom spun-Aluminum filter cells are also available
to fit any telescope, on
special order. Please contact us for pricing and availability.
Prices typically range from $80-$100.
Baader 2X/4X Telecentric Lens Systems
Baader Planetarium has designed a new optimized
telecentric system for use with the Solar Spectrum H-Alpha systems.
A telecentric system is used to convert shorter focal ratio telescopes
to the required f/25 or greater beam needed by the Solar Spectrum
filter. More than a barlow lens, the telecentric ensures that the
f/30 beam maintains a consistent normal incident angle across the full
filter width. This lens system has been optimized to maintain an
exceedingly high optical quality (>99% strehl at 656.3nm). Hard
Dielectric IR coatings further help to reject IR energy and protect the
rear etalon from excessive heat energy.

2X
4X
For further information, please see:
Telecentric System
(150 kB)
Telecentric systems are available in a 2X and a 4X
version. Please contact us for further specifics and availability.
- Baader Telecentric Lens System, 2X (#TZ-2)
- Baader Telecentric Lens System, 4X (#TZ-4)
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Last Update
06/22/08 |