Safety Film Solar Filter Material
Cool-Ceramic Herschel Safety Wedge Solar Prism
Calcium K-Line Filter
Solar Continuum Filter
H-Alpha Systems and Baader H-Alpha Accessories
AstroSolar™ Safety Film, White Light Solar Filter
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
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.
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".
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
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 /
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,
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).
Before mounting the AstroSolar, be sure to peel off the removable clear
protective film that is present on one side of the film.
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
Baader 2" Cool-Ceramic Safety Herschel Prism
Images taken with the Herschel Safety Wedge
New Baader Planetarium
2" Cool-Caramic Safety Herschel Prism delivers 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 NEW Baader
2" Cool-Caramic Safety Herschel Prism 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" ultra-smooth wedge prism and
optimized optical design
for stray light elimination, the Baader Safety Herschel Wedge maximizes
image contrast and sharpness. The large
first-surface prism has high surface quality and
smoothness over its entire surface, which will not break down at
magnifications well over 100x, permitting full-disc photography and imaging
with no resolution or contrast loss across the full field.
Efficient internal baffling and prism rear-face multicoatings further
reduce scatter and maximize contrast.
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 Baader 2"
Clicklock Eyepiece Clamp. 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.
Our latest version incorporates an innovative internal Light Trap and
Ceramic Tile backplate developed by
Baader Planetarium. This development takes the Herschel Wedge into
the 21st Century, by rendering the output energy cool and diffused,
while completely sealing the prism body!
In all other herschel designs, the waste energy is simply deflected out
of the rear face of the prism by an angled mirror, also leaving openings
for accidental or prying fingers to discover... 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. The special die-cast magnesium body also
conducts away the heat more efficiently than aluminum. The remaining light is passed into a special
translucent ceramic back plate.
Integrated Solar Finder. Another
unique aspect of the new Cool-Ceramic Safety Herschel Prism is the
integrated solar finder. The sun's defocused image can be readily
seen projected onto the translucent ceramic backplate, permitting fast
and easy aiming.
Each Baader Safety Herschel Wedge also includes a pre-installed 2"
Solar Continuum Filter!
With the Solar Continuum, the contrast and image stability is further
enhanced in all telescopes (APOs as well as Achromats). Users of
Achromats will find the Solar Continuum is indispensible, providing an
image that rivals the sharpness and contrast of an Apochromat (with the
Solar Continuum the image is presented in a deep lime green color). 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 for pure white light views, if desired (but the ND=3.0 must not be removed).
We 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,
ND0.6/1:4 ). 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
All of the fine-optically polished
genuine Baader ND filters 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.
NEW: Each Safety Herschel Wedge
now includes a custom foam lined carrying case that holds the Herschel
Wedge along with storage area for all of the filters provided
in the V and P versions.
(carrying case shown with HERSCH-P model)
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
link for additional safety information.
Similar in length to any 2" diagonal, the Baader
Cool-Ceramic Safety Herschel Prism
requires more back-focus than a 1.25" accessory. The
length of the Herschel is approximately 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 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
T2-08 1.25" Clicklock eyepiece clamp.
(click on image for additional information, 722kB pdf)
For a recent full review of the Cool-Caramic
Safety Herschel Prism by Ted Wolfe, please click on the following Cloudy
"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."
"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
- Baader Herschel Wedge Solar
Prism 2", including fitted carrying case (#HERSCH-V)
- Baader Herschel Wedge Solar
Prism 2", including fitted carrying case
| 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
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.
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. Also, the polarizing filter must be used on the
eyepiece or eyepiece reducer, never ahead of the ND3.0 filter (the
polarizing filter must be located after the ND3.0 filter to prevent
damage to the delicate internal layers of the polarizing filter).
- Baader Polarizing Filter, 1¼”
- Baader Polarizing Filter,
PRICING | ORDERING
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" Clicklock 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
Maxbright Binoviewer (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,
PRICING | ORDERING
Herschel Wedge Accessories:
Fitted Foam-Lined Carrying Case
Custom foam lined carrying case holds the 2" Cool-Ceramic
Safety Herschel Prism, with storage area for all of the filters provided
in the V and P version.
- Carrying Case for 2" Cool-Ceramic Herschel Prism,
available separately (#HERSCH-CASE)
(carrying case shown with HERSCH-P model)
PRICING | ORDERING
Calcium K-Line Filter
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,
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 ).
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.
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.
* 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.
© M. Weigand
- Baader K-Line Filter,
1.25"(including 200x290mm AstroSolar ND-3.8), (#CAK-1)
PRICING | ORDERING
Solar Continuum Filter
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
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
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
Solar Continuum Filter Transmission Curve
- Baader Solar Continuum Filter, 1¼”
- Baader Solar Continuum Filter,
PRICING | ORDERING
Solar Spectrum H-Alpha
Systems and Baader Accessories
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 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...
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 $2,800. Compared to the
wider band single or double stacked objective etalon systems, the Solar
Spectrum filters offer greatly improved performance at significantly
Solar Spectrum H-Alpha Filter Systems
Solar Spectrum produces what we have found to be the
ultimate in high resolution H-Alpha filter systems. With over 20
years of experience in making filter systems for professionals as well
as amateurs, Solar Spectrum brings an unmatched level of expertise to
bear in producing filters at prices accessible to amateurs. This
experience uniquely enables them to deliver a high level of quality and
consistency in very narrow filters (< 0.3A) which are extremely
demanding to produce.
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 telescope 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, without any loss in
resolution. Each Solar
Spectrum filter system includes the rear mounted etalon assembly (which
includes an integrated thermoelectric heater/cooler),
programmable 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/20 will also
require a telecentric lens to produce the desired 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 16-24 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 lowest cost 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: Our best value. 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
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 produced up until 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 red glass used
in producing the older generation of ERFs is of very poor and variable
internal quality. In order to produce ERFs from red glass, Baader
had to complete and polish each ERF, then interferometrically inspect
every one for internal defects, resulting in having to dispose of
far more ERFs than they were able to keep. Its no wonder why other
red glass ERFs have such a poor reputation, particularly in sizes over
3" in aperture.
rejection is now accomplished using ultra-hard dielectric coatings on both sides of the
substrate, and also serve to protect the glass, making it highly
resistant to scratches. D-ERF filters are made from high grade
optical glass which is free of any internal defects. The thick
substrates are polished plane-parallel,
smooth, and flat to an amazing 1/10 wave p-v over the entire surface.
Only by using thick substrates can a high surface accuracy be achieved
and held in use (for example, the 90mm ERF is 5.5mm thick. Thinner
substrates are not capable of holding such high surface accuracy). The special dielectric filter stacks are precisely balanced
on opposite sides to maintain
the superb optical flatness after coating.
For further information, please see:
(150 kB) The D-ERF
transmission curve can also be found by clicking the link below
D-ERF Transmission Curve
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
- 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 $100-$125.
Baader 2X/4X Telecentric Lens Systems
Baader Planetarium has designed a new optimized
telecentric system for use with Solar Spectrum H-Alpha systems.
A telecentric system is used to convert shorter focal ratio telescopes
to the desired f/25 or greater beam needed by the rear mounted Solar Spectrum
filter. More than a barlow lens or barlow lens based system, the
Baader telecentric ensures that the output beam maintains a consistent normal incident angle across the full
filter width. The result is a consistent bandwidth and high image
contrast across the field of view. This lens system has been optimized to maintain an
exceedingly high optical quality for dedicated solar use (>99% strehl at 656.3nm).
Simpler barlow or barlow-based systems are not able to produce this
level of accuracy or telecentricity. Hard
Dielectric IR coatings further help to reject IR energy and protect the
rear etalon from excessive heat energy.
For further information, please see:
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)