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Posts Tagged 'filter'

NBX – the new dual nebula filter from IDAS

October 19 2020, Jan Ströher

A new, high quality dual band filter has appeared on the market, in the form of the NBX nebula filter from Japanese company, IDAS.  It is especially efficient for nebula photography using fast optics, like the Celestron RASA, for example. Like the existing IDAS (Astro Hutech) nebula filters, the new NBX is of impeccable quality and workmanship.

The IGAD (Ion-Gun Assist Deposition) coating technology which has been specially applied to astronomical filters by the Japanese manufacturer, Astro Hutech, was originally developed for optical communication, where long-term stability (> 25 years) is required in rough field conditions.

IDAS NBX 48mm nebula filter

This leads to filters with robust coatings and durable spectral stability – even at extreme temperatures and humidity levels. This stability is especially important for bandpass curves with steep sides, such as H-alpha, LPS filters and other narrow band filters. Filters with IGAD coatings almost completely eliminate bandpass shifts of +/- 3 or 4nm, which are typical with standard filters.

The NBX is a dual filter which specifically focuses on OIII and H-alpha lines. The NBX‘s transmission curves in the H-alpha and OIII ranges are very clearly illustrated in these two figures:

Transmission curves in H-alpha


Transmission curves in OIII


You can see that the IDAS NBX filter primarily realises its full potential when used with very fast optical systems and astrographs, such as a Celestron RASA, especially fast Newtonian reflectors with f-numbers between f/2 and f/4 and special devices, such as the Officina Stellare Veloce RH 200 Mark II-AT (Riccardi-Honders).

The NGC 281 “Pacman” Nebula in the constellation Cassiopeia

This dramatically increases the contrast within emission nebulae, which predominantly consist of oxygen (OIII) or hydrogen compounds (H-alpha). Additionally, longer exposure times are no longer required, predominantly due to the use of the above-mentioned, extremely fast optics, but also due to the NBX filter’s special contrast effects. The filter is ideal for use with ‘one shot’ colour cameras and monochromatic CMOS cameras. An IR blocking filter is then no longer required. Additionally, the NBX is parfocal with other IDAS LPS nebula filters.

Good conditions for observing Venus

January 20 2020, Jan Ströher

In the coming weeks Venus, our “sister planet”, will become a good object for observing. The planet is a bright, easily detectable object in the morning or evening sky, but it is usually located very close to the horizon with corresponding atmospheric disturbance and rather short observing times. This will improve from around the end of January, when Venus will become progressively brighter and visible for longer in the evening sky. Then the planet will be found easily with the naked eye immediately after sunset and can be observed for almost four hours.

Even good binoculars, such as the Omegon Nightstar are suitable for observing. In telescopes with an aperture from around 90mm, Venus can already be identified as a small disc. Just like the Moon, the planet exhibits different phases, although details of the surface remain hidden owing to its very dense atmosphere. The cloud structures can be distinguished very well with telescopes from 130mm aperture. The use of a suitable filter (violet, dark blue, blue) is recommended to improve the contrast.

Credit: EXAME/JAXA/Divulgao, Brazil

Venus is the second innermost planet in our solar system and is a similar size to Earth. Its atmosphere consists of carbon dioxide, nitrogen, sulphur dioxide and various noble gases. This composition, combined with its proximity to the Sun, makes our neighbouring planet a hostile and mysterious world. As it orbits the Sun, Venus rotates backwards, that is in exactly the opposite direction to our Earth. Therefore on Venus the Sun rises in the west and sets in the east. After the Moon, the planet is the brightest object, but, just like Mercury it is only visible in the morning or evening sky – hence it is also given the designation “morning-” or “evening star”.

From mid-January, Venus dominates our evening sky immediately after sunset on the southwestern horizon. Between then and the end of March it changes its position from about 25° to 46° and reaches a brightness of -4.7mag by the end of April. During this period it moves towards the western horizon and passes through the constellations Aquarius, Pisces and Aries. In April it reaches Taurus and can even be found close to the Pleiades (M45) at the beginning of April.

From January to May it’s best to track Venus using a star chart.

Credit: Planetarium Bochum

Have fun observing Venus in 2020!

New: NB1 nebula filter from IDAS

March 25 2019, Stefan Taube

Luminescent emission nebulae, supernova remnants and planetary nebulae are all particularly beautiful objects pertaining to the night sky. This applies both to the simple process of visual observation, as well as to astrophotography. Nature illuminates such nebulae in specific spectral colours: the red light of hydrogen, the blue-green light of oxygen ions and also in the colours of sulphur and nitrogen ions.  Nebula filters enable these colours to pass through whilst blocking the diffused light of the natural luminance of the sky and of light pollution. The result is a marked increase in contrast.

With the Nebula Booster NB1, the filter specialists IDAS are introducing a new, very high-performing filter of this type onto the market, and one that is not overly expensive! As the transmission curve shows, the filter has high transmission and is permeable for all relevant spectral lines, with a surprisingly narrow passband: A real nebula intensifier!

Transmission curve IDAS NB1


The filter is ideal for photographing large nebula regions since it enables the typical colours of these objects to pass and blocks the disruptive skyglow. The filter quickly and completely cuts off near infrared up to 1100 nanometres. This is important since cameras are sensitive to this range, but telescopic lenses are optimised for the visible spectral range and are faulty in the infrared range.

IDAS Nebula Booster NB1

IDAS Nebula Booster NB1


The Nebula Booster NB1 is available with two versions which cover both of the common filter thread sizes and can be screw-fitted to the housings of eyepieces or cameras.

5 Simple Ways to See and Photograph the Lunar Eclipse and the Opposition of Mars

July 13 2018, Marcus Schenk

Attention all lovers of nature, amateur astronomers and night owls: the night of the 27th of July, 2018 will be totally different.  In this particular night, we will experience the Opposition of Mars and a rare Total Lunar Eclipse in Europe!  It is sure to be a midnight Summer dream, in the middle of warm temperatures and mystical experiences.

In this article, you will learn about, that which you can use to observe and photograph the Total Lunar Eclipse and Mars.

Another interesting point: currently, there are a number of other planets to see. Now is the perfect opportunity to jump into Astronomy.  You will be rewarded with a fireworks show of planets.  Mars, Jupiter, Venus and Saturn are waiting for you to rediscover them!

As the night slowly falls, the Moon will rise in the southeast.  Our satellite will look unusual and simultaneously fascinating.  Almost completely eclipsed, it will rise higher and higher.  The “blood Moon”,  which evoked fears and superstitions of death and destruction in earlier times, will be visible for us to witness with our knowledge and science in a relaxing manner and with a smile.

The highlight of this year: at a length of 1 hour and 44 minutes of totality, we will get to enjoy the longest Lunar Eclipse of the century! More information about this event is available below.

Now you can read on to learn about the 5 ways and effective products, to observe the Moon and the Planets. Let’s go!


1. Discover the Sky with Binoculars

The lunar eclipse is visible with the naked eye,  but with a pair of binoculars, the Moon in the Earth’s shadow becomes an especially intense experience. For an great observation, we recommend the Omegon Binoculars Nightstar 20×80.  These binos are a great alternative to a telescope or as an entry into Astronomy.  They are bright and something that you can always carry with you.  Just point the binos to the sky or mount them on a tripod.  Then you will see the Moon in all its glory and innumerable craters.  It is amazing with both eyes, as if you were there.  But there is more.  You can can even view  Jupiter and its moons as well as starclusters, such as the Pleiades or the Andromeda Galaxy.

Großfernglas 20x80

The Omegon Binoculars 20×80

2. Getting closer with a telescope

Much like a mega zoom into the cosmos: A telescope allows you to see real detail. Observe the entire Moon, singular lunar craters, Jupiter, or Saturn with its massive system of rings. However you want.  The possibilities are endless!  With a greater magnification, only available with telescopes, you will be able to see Mars for the planet that it is and not just the red “star” in the night sky.  The Omegon AC 70/700 AZ-2 is the most budget-friendly entry point.  With a 70mm aperture, it collects 100 times more light than the naked eye.  The eyepieces enable a 35x and 70x magnification, or in combination with a barlow lense up to 140x.  More details and more resolution is available in the Omegon AC 90/1000 EQ-2.  The telescope is our tip for entry into lunar and planetary observing.  With a 90mm aperture, you will be able to see many details, such as the cloud bands on Jupiter or the polar caps on Mars.


The Omegon AC 90/1000 EQ-2 – Recommendation for entry into Astronomy

3. The simplest way to your own astrophotos

A photo of the lunar eclipse?  It’s possible with the simplest tools.

With a telescope, the path to your own photos is just a small step.  The best camera for such a task is right in your pocket: your smartphone!  Pick up a Smartphone adapter, which will keep your phone perfectly positioned above the eyepiece.  We also offer the more budget-friendly Omegon Smartphone Adapter, which demands a bit of finesse or the Omegon Easypic Universal.  This smartphone adapter is a self-centering and easy-to-use device.  It only takes one minute and you will already have taken your own lunar photo.


Omegon Easypic Universal Smartphone adapter

4. The right eyepiece is decisive, when it comes to details

With eyepieces, you often must separate the wheat from the chaff.  An eyepiece is essentially an extended arm of the telescope’s optic and you should put a lot of stock into selection, just as you would with a telescope itself.  A good tip would be to replace old or standard eyepieces with high quality ones, which can provide you with a significantly better image.  Excellent crispness and great contrast can be found in the Omegon LE Planetry Eyepieces for all 1,25“.  The customer reviews range from “just fantastic” to “you cannot believe it”.

The Family of Omegon LE Planetary Eyepieces

5. Color filters for better contrast

Much like a chain, the planets of Venus, Jupiter, Saturn and Mars will appear to us in a line, and all after darkness has fallen, during the most comfortable time of year.  The constellation of planets is so rare, that now is the time to jump into astronomy.  Amateurs can easily pinpoint the planets and see details of each.  Polar caps and other structures on Mars, or the big red dot on Jupiter become more visible with the appropriate color filters.  Placed into the eyepiece, filters can lead to an epiphany for any motivated observer.  The Omegon Color filter set features the most important ones for all planets.  Other contrast filters or our Lunar Filter are also a helpful inclusion to your collection.

Farbfilter für die Planetenbeobachtung

Color filter set with 6 color filters


Other information about the Total Lunar Eclipse and the Mars Opposition is available here:

Infographic: Total Lunar Eclipse on the 27th of June 2018

Mars Opposition 2018: How to Observe Mars and its Details


Mars Opposition 2018: How to Observe Mars and its Details

June 29 2018, Marcus Schenk

On the 27th of July, 2018, the time will finally be upon us: our neighbor, Mars, will stand in opposition to the Sun.  Such an event happens every two years, but this time around is something much more special.  The last time Mars was so close to Earth, during opposition, was back in 2003.  This year, the red planet will come within 57 million kilometers, which is about the same distance as 15 years before.  Mars will appear to be about half of the size of Jupiter, something only rarely observable, but with numerous details.

For more info about the Opposition, how to observe, which details to look for and which accessories improve your chances of a rewarding observation, read on below:

Photo: B.Gährken


  1. Mars: The facts about a fascinating planet
  2. The Mars Opposition: What is it?
  3. Why only every two years?
  4. Why will Mars be so large this year
  5. Which Telescope?
  6. You can see this on Mars
  7. Helpful accessories, to improve your observation

1. Mars: The facts about a fascinating planet

With a diameter of 6,000 km, 687 day orbit and a mountain at 27,000 meters – Mars is only half as large as the Earth, but resembles our home very much.  Much like Earth, Mars is home to a rocky surface with mountains, plateaus and canyons.  Valles Marineris is a massive 4,000 km long canyon, with a width of 700 km, and is considered the Grand Canyon of Mars.  Comparatively, our Grand Canyon is relatively small at only 450 km in length and with a 30 km width.

Mars features other similarities, with its polar ice caps and even seasons.  Standing on Mars, you would also see sunrises and sunsets.  You could even see Earth with a telescope.  The planet even features a similar tilt in its orbital path and a day lasts 24 hours and 40 minutes.

What a nice twin, right?  Many space pioneers think so.  And to top it all off, recently NASA revealed clues that the planet was able to support life.  There are, of course, a few disadvantages to lifing on Mars: the cold.  A thick jacket won’t be enough, given that the temperatures drop to -85°C.  Nevertheless, temperatures could reach about 20°C at the equator.

Even the oxygen levels and atmospheric pressure varies greatly: 95% carbon dioxide, 1.8% nitrogen und 0.1% oxygen.  On Earth: 78% nitrogen and 20% oxygen. In other words, breathing on Mars would be suffocating.  Take off your spacesuit and your blood would boil in short time, as if you were at 35 km in altitude above the Earth – 3 times higher than cruise altitude of a commercial jet.

2. The Mars Opposition: What is an opposition?

An opposition occurs, when Mars stands in a straight line with Earth and the Sun.

3. Why only every two years?

Mars orbits the Sun once every 687 days, so roughly 2 years.  We on Earth travel a much higher speed and only require 365 days to orbit.

Imagine that both planets start at the same spot.  The Earth would lap Mars at some point during its orbit.  Given that Mars is also orbiting, one trip around the Sun would not suffice, however.  Only after 780 days will the Earth and Mars be aligned once again.  An opposition!

4. Why will Mars appear to be so large this year?

Mars is pretty conspicuous in the sky this year.  The red planet rises as dusk falls, and will shine bright in the night sky until dawn.  The disk will appear to be enormous!  It will increase to up to 24 arc seconds.  Through a telescope, Mars will appear especially large, meaning we will be able to identify many details on the surface.  It is a unique chance for observers and astro-photographers.  Mars only appeared slightly smaller during the Opposition of 2003.

Mars does not have a circular orbit, rather an off-center orbit around the Sun.  That is why its distance to Earth can vary so greatly.  Depending on the position, oppositions can vary between 101 m and 55 m km.  This year: 57.7 m km.  In 2020, 62.2 m km and two years later 82 m km.  By year 2035, Mars will once again be about as close as this year.

For observers in the norther hemisphere, the close oppositions will take place below the celestial equator, since they occur in the Summer months.  The planet will not be found high above the horizon, but rather just above it: this year, just 15°.

5. Which Telescope?

Mars is bright and an object, that you can see with the naked eye.  It will rise late in the eveing in the south west, climbing ever higher and reaching its meridian on 27th of July, 2018.  Shortly before sunrise, the red planet will once again disappear under the horizon.  You cannot miss Mars, since it will be the only bright object with a very bright and red color.

During the opposition, Mars will be quite large.  That is why you could use just about every telescope to have a look at the planet, even a telescope with a 70-80 mm aperture.  A good beginner’s scope for planets would be the Omegon AC 90/1000 EQ-2.  With an intermediate or large telescope from 150 – 200 mm, you will be able to enjoy a greater resolution, which is important if you want to be able to see the small details.  Keep an eye out that the telescope is well calibrated and adjusted for the temperature outside – important factors for a good, contrast-rich image.  Many observers cherish Dobson telescopes, since they are inexpensive, bright, and easy to work with.

Mars bei 250-facher Vergrößerung

Mars through a telescope

To view Mars, use a magnification of at least 100.  Reason is, the small the planet, the more difficult it will be to see detail.  Shorter focal lengths additionally afford you the greatest magnification.  Magnifications of 200 – 300x are sensible to use.  Hint: high-quality Televue Eyepieces on Sale are available here.

6. What to See on Mars

If you have a telescope of 100x, mars will appears only as red ball.  With patience, you should be able to identify the bright, white polar caps.


Mars with notations, Image: B. Gährken

The most noticeable dark area on the red planet is the Syrte, which is a large, dust-free, and high plateau with a width of 1,300 km.  The area lies close to the equator and should be noticeable with an intermediate telescope.  The Hellas Basin is a large, bright region, found south of Syrte and often home to storms.  Of course, we will only be able to see these two regions, if Mars happens to be sharing this side of itself.  Additionally, white clouds of meteorological phenomena can be seen with larger telescopes and color filters.

A foldable “Mars Map”  from Orion is helpful in preparing for observations and photography.

7. Helpful Accessories

The ADC Corrector: for more contrast on the horizon

If we observe an object just above the horizon, the object could already set.  The light of the cosmos is often distorted, while passing through the atmostphere or bowed.  We see the same effect, for example, in a glass of water or a straw.  The water is an optically dense medium – just as a straw would in a different way.  Our atmosphere does the same.

ADC Korrektor

A Schmidt-Cassegrain Telescope with ADC and a Toupek camera

Is that a problem? Indeed, when we talk about an astronomical object.  Blue and red light is distorted in different ways.  Objects then exhibit a colored edge and appear to be contrast-less.  The images are just less sharp, than those higher in the sky.

The ADC from Omegon produces – if you will – a negative color defect, which works against the atmosphere.  The planet Mars plays a role here.  Mars appears, to float just a bit higher.  When one of our colleagues tested the ADC the first time, he noted, “The effect was massive.  It appeared as if the telescope was suddenly replaced with another.”


The atmosphere has an effect, like a simple lens and the colors of light are dispersed in various ways.  An object appears higher, as a result, than it really is, in addition to color fringes.  Image sources: NASA/JPL Solar System Simulator, Courtesy NASA/JPL-Caltech

In the next few years, many of the planets will be found quite close to the horizon.  But, the ADC is your best hope.  You can use it for visual observations, as well as for photography.  Putting it to use is also quite simple: just place it into the recess, where the eyepieces normally is attached.

The advantages of the ADC in a nutshell:

  • ADC corrects atmospheric dispersion
  • Color fringes are reduced or disappear
  • Sharpness and contrast increase, as if the planet were higher in the sky
  • Just put it in the eyepiece recess and adjust the prisms.

Color filters: to unlock Mars’ detailed surface

Color filters are very useful for planetary observations, since they increase contrasts and make many details visible, which you may not see otherwise.  The only requirement is that you should have some experience in observing, because seeing in astronomy is learned.

Color filters are available in sizes 1.25″ or 2″ and are simply screwed into the threads of the eyepiece.

But which details can you see on Mars?

Farbfilter für die Marsbeobachtung

Color filters are screwed directlz into the thread of your eyepiece.

Green filter: with it, you can directly enhance the surface, clouds and freezing fog.

Blue filter: only used for freezing fog and clouds.

Yellow filter: Great for seeing the occasional several week-long dust storm on the surface, by brightening such areas.

Orange and Red filters: Orange filters enhance the bright/dark structures of the surface and are the standard filter for observing Mars. The red filter does the same, but only utilized in large telescopes.

Tip: There are also special Mars filters, which increases greatly the contrasts of the red planet.

Filter wheel: For the quick switch

When you want to use several different filters, we recommend the filter wheel, for a quick switch between filter types.

Camera: Capture Mars

Do you want to photograph Mars? Then get your hands on a Touptek Camera G3M178C, which offers a high sensitivity and a resolution of 6.4 megapixels.  Plus, it is extremely fast.  With 59 images per second, you can put the shortest moments to use, resulting in sharp images of the red planet.

Aufbau für Planetenfotografie

The assembly of a successful Mars photography session: a Touptek camera, a barlow lens with a flip mirror and an eyepiece.

Flip Mirror

A great aid for planetary photography, making centering the planet in the dark hours no contest.  With a flip mirror, you can switch between an eyepiece and camera in mere seconds.

Get out and observe!

Don’t wait until the year 2035! This Summer is a great opportunity to marvel at Mars in all its glory.  In contrast to the opposition in 2003, camera technology has come quite a long way.  Instruments like the ADC additionally enable you to view objects on the horizon.  Get your telescope read and have a look at our nearest neighbor this Summer!

Product tip: Want to show your enthusiasm? Then get your hands on the Mars T-shirt!  The backside features all the info of the opposition: distance, size, and brightness.  Order now!

Mars T-shirt

Mars T-shirt

Astronomik: new clip filters for Canon DSLR cameras

July 31 2017, Stefan Taube

Northern German company Astronomik is a specialist for astronomical filters for astrophotographers or purely visual star gazers. Clip filters are a special innovation of Astronomik. These filters have a special mounting shape, which allows them to be placed directly into a DSLR or system camera – without using any tools!

Astronomik currently offer clip filters for:

The camera mentioned last is designed with extremely high sensitivity. We offer this camera as a specially astro-modified camera. For more information please follow this link: Sony Alpha 7s Astro.

For APS-C Format EOS cameras from Canon, Astronomik have now developed a new series. A special feature of these new XT filters is the very thin carrier with a thickness of only 0.3 mm, to which the filter layer is applied. When using filters with thicker glass carriers, image faults may become visible in the corners of the photos. Stars appear slightly dash shaped. This can be particularly noticed when using short focal lengths. So if you would like to use a Canon EOS with the camera lens on a camera mount to take wide angle shots of the night sky, an XT filter might be the right investment.

XT filters are available in the usual versions, from CLS to H-alpha all the way to SII filters. For novices we especially recommend the CLS filter, which suppresses artificial light pollution.

The red transmission curve reveals: The CLS filter blocks the light from the yellow street lamps.

The red transmission curve reveals: The CLS filter blocks the light from the yellow street lamps.


By the way: Removing a clip filter from the camera housing is just as easy as putting it in.

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