Astronomy filters for lunar, planetary & deep sky viewing

Bring out the best in every night sky object

Filters

EXPLORE SCIENTIFIC Solarix Solar Filter Film A4

Explore Scientific Solarix Solar Filter Film.Watch Solar Eclipses, Sun Spots, Planet Transits, crossing aircrafts and satellites.Suitable for making your individual solar filter for telescopes, binoculars, photo- and video cameras.New developed solar filter film that has the optical quality of the glass with the advantages of impregnated polymer.Collateral protection by using impregnated polymer and additional filter coated surface.Creates a very natural and yellow solar image.Also qualified for high magnifications.Consistent brightness and even density with any aperture.Ideal for visual observing and photographic use.Light weight and does not require re-balancing tube assembly.Flat surface compared to other thin film filters that have wrinkles and creases.Resistant against any damage.Construction manual included for making your individual solar filter and eclipse glasses.100% safeSpecifications:Material thickness: 0.05mm Optical density: 5Optical transmission: 1/1000 of 1% (99.999% incoming light blocked)Dimension: A4 - 210 x 297mmSCOPE OF DELIVERYSolar Filter Film, A4 sizeHard carton stencil for cutting out a telescope filter holder and eclipse glassesContruction- and Instruction manual Additional materials which need to be purchased separately:Double sided gluing tape.Universal adhessive glue.Paper scissor.

€19.90*

EXPLORE SCIENTIFIC Filter 1.25" YellowGreen No.11

Watching the Moon surface through the filter, the contrasts will enormously increase. Same with planet Mars. On the huge planet Jupiter, when using the filter, you can even see the contrasts between the cloud-bands and a lot more details. Starting with a telescope diameter of 8“ and a clear sight, you even get to see various details of Saturn.What ist a color Filter for and do we really need it ? Color Filters darken the light slightly, that reaches the eye or the sensor of the camera. This eliminates for instance stronger transitions. The result is that your picture turns out with more contrast which automatically shows more details.FEATURESMade from high-quality optical glassFilter glass is absolutely parallel All optical surfaces have anti reflex coatingsFilter housing from black anodized aluminumFilter threads on both ends (female/male)Multiple filters usage is possibleSCOPE OF DELIVERYColor filterProtection-case

€8.00* €14.90* (46.31% saved)

EXPLORE SCIENTIFIC Sun Catcher Solar Filter for 9"- 10" SC Telescopes

Explore Scientific's Sun Catcher Variable Large Aperture Solar Filters are available in many sizes to work on most telescopes from 60mm up to 10-inch Schmidt-Cassegrain and of course all Bresser and Explore Scientific Telescopes. The Solar Filter material being used is the new advanced 'Solarlite' Film manufactured by world famous Thousand Oaks Optical through years of research and development. 'Solarlite' a new solar film that has the optical quality of glass with the advantages of impregnated polymer. Perfect also for the solar astrophotographer.NOTE: All Explore Scientific Solar Equipment is rated ISO12312-2 supplied by Thousand Oaks Optical and approved for direct observation of the Sun. These solar filters are available in different sizes, the picture above shows three different sizes as an example. This is the solar filter with 203mm filter diameter.SPEZIFICATIONSSpecial objective filter for safe solar observationsISO12312-2 ratedField-stop diameter 203mmFits to outer telescope tube diameter from 200 to 280mmQuick individual match with your telescope diameterFast Setup - Easy UseSCOPE OF DELIVERY1x Sun Catcher solar filter

€30.00* €59.90* (49.92% saved)

EXPLORE SCIENTIFIC Filter 1.25" Light Yellow No.8

Watching the Moon surface through the filter, the contrasts will enormously increase. Same with planet Mars. On the huge planet Jupiter, when using the filter, you can even see the contrasts between the cloud-bands and a lot more details. Starting with a telescope diameter of 8“ and a clear sight, you even get to see various details of Saturn. Minimum 2" aperture recommended.What ist a color Filter for and do we really need it ? Color Filters darken the light slightly, that reaches the eye or the sensor of the camera. This eliminates for instance stronger transitions. The result is that your picture turns out with more contrast which automatically shows more details.FEATURESMade from high-quality optical glassFilter glass is absolutely parallel All optical surfaces have anti reflex coatingsFilter housing from black anodized aluminumFilter threads on both ends (female/male)Multiple filters usage is possibleSCOPE OF DELIVERYColor filterProtection-case

€8.00* €14.90* (46.31% saved)

EXPLORE SCIENTIFIC Filter 1.25" Light Red No.23A

The blue/blue green light is totally blocked. The contrast between the card and the lighter zones will enormously increase. This is truly helpful when you watch Jupiter or Saturn. Or for mars, watching the poles.What ist a color Filter for and do we really need it ? Color Filters darken the light slightly, that reaches the eye or the sensor of the camera. This eliminates for instance stronger transitions. The result is that your picture turns out with more contrast which automatically shows more details.FEATURESMade from high-quality optical glassFilter glass is absolutely parallel All optical surfaces have anti reflex coatingsFilter housing from black anodized aluminumFilter threads on both ends (female/male)Multiple filters usage is possibleSCOPE OF DELIVERYColor filterProtection-case

€8.00* €14.90* (46.31% saved)

EXPLORE SCIENTIFIC 2" CLS Nebula Filter

Besides air turbulence, the brightening of the night sky is the biggest obstacle to observing faint objects beyond the solar system. Street lamps and other artificial lighting mean that the sky in human settlements is no longer really black. This affects the contrast and thus the perception of deep-sky objects. Depending on the type of celestial object, however, part of disturbing artificial light can be filtered out, making it easier to observe fainter targets.The EXPLORE SCIENTIFIC CITY LIGHT SUPRESSION - or CLS - filter uses the fact that the artificial lighting is not evenly distributed over the entire spectrum. These colours - in the case of the EXPLORE SCIENTIFIC CLS nebula filter, above all the typical colours of mercury and high-pressure lamps, used in street lighting - are suppressed, but the emissions of deep-sky objects are allowed through. With a slightly brightened sky, some relatively bright deep-sky objects are practically invisible with a telescope, for example the large galaxy M101. Using this filter makes observation much easier. A must have for any visual amateur astronomer. The CLS can also be used as a useful photographic filter - helping to improve the quality of your telescopic deep sky photos.The EXPLORE SCIENTIFIC nebula filters are delivered with an individual test report - so you can be sure of receiving high-quality filters.SPECIFICATIONS:eliminates disturbing light - e.g. from street lightingenables observation of faint deep sky objectsWHAT'S INCLUDED:1x nebula filter

€57.00* €83.00* (31.33% saved)

EXPLORE SCIENTIFIC Sun Catcher Solar Filter for 80-102mm Telescopes

Explore Scientific's Sun Catcher Variable Large Aperture Solar Filters are available in many sizes to work on most telescopes from 60mm up to 10-inch Schmidt-Cassegrain and of course all Bresser and Explore Scientific Telescopes. The Solar Filter material being used is the new advanced 'Solarlite' Film manufactured by world famous Thousand Oaks Optical through years of research and development. 'Solarlite' a new solar film that has the optical quality of glass with the advantages of impregnated polymer. Perfect also for the solar astrophotographer.NOTE: All Explore Scientific Solar Equipment is rated ISO12312-2 supplied by Thousand Oaks Optical and approved for direct observation of the Sun. These solar filters are available in different sizes, the picture above shows three different sizes as an example. This is the solar filter with 90mm filter diameter.SPEZIFICATIONSSpecial objective filter for safe solar observationsISO12312-2 ratedField-stop diameter 90mmFits to outer telescope tube diameter from 90 to 160mmQuick individual match with your telescope diameterFast Setup - Easy UseSCOPE OF DELIVERY1x Sun Catcher solar filter

€25.90*

EXPLORE SCIENTIFIC Filter 1.25" Dark Yellow No.15

Watching the Moon surface through the filter, the contrasts will enormously increase. Same with planet Mars. On the huge planet Jupiter, when using the filter, you can even see the contrasts between the cloud-bands and a lot more details. Starting with a telescope diameter of 8“ and a clear sight, you even get to see various details of Saturn. Minimum 5" aperture recommended.What ist a color Filter for and do we really need it ? Color Filters darken the light slightly, that reaches the eye or the sensor of the camera. This eliminates for instance stronger transitions. The result is that your picture turns out with more contrast which automatically shows more details.FEATURESMade from high-quality optical glassFilter glass is absolutely parallel All optical surfaces have anti reflex coatingsFilter housing from black anodized aluminumFilter threads on both ends (female/male)Multiple filters usage is possibleSCOPE OF DELIVERYColor filterProtection-case

€8.00* €14.90* (46.31% saved)

EXPLORE SCIENTIFIC Filter 1.25" Green No.56

The green filter is to increase the contrasts enormously between the red and the blue regions of the cloud structures on the gas planets Jupiter and Saturn. Seeing our Earth Moon through the green filter, the contrasts of each ray crater become clearly more visible.What ist a color Filter for and do we really need it ? Color Filters darken the light slightly, that reaches the eye or the sensor of the camera. This eliminates for instance stronger transitions. The result is that your picture turns out with more contrast which automatically shows more details.FEATURESMade from high-quality optical glassFilter glass is absolutely parallel All optical surfaces have anti reflex coatingsFilter housing from black anodized aluminumFilter threads on both ends (female/male)Multiple filters usage is possibleSCOPE OF DELIVERYColor filterProtection-case

€8.00* €14.90* (46.31% saved)

EXPLORE SCIENTIFIC 2" Variable Polarizing Filter

Universally usable variable polarizing filter with a 2" filter thread.This variable polarizing filter allows for a continuous adjustment of the image brightness. This is very helpful to level strong differences in contrast of different observation objects individually. Particularly for lunar and planetary observations but also for solar observations this filter prevents an outshining of details.Solar observations ONLY together with an adequate solar filter !!! Particularly when a Herschel wedge is used and with large objective lens apertures the use of the variable polarizing filter can reduce the brightness of the observation object to a confortable level. The large adjustment range of 40% to 1% light transmission and the neutral grey filter effect create a comfortable and unadulterated image.The handling is very simple. The desired filtering level is set by turning the two sides of the housing against each other.A 2.0" filter thread on both sides (female/male) allow for the simultaneous use of additional colour filters.FEATURESvariable polarizing filterindividually adjustable image brightnessmade from high-quality optical glassblack anodized aluminium housing2.0" filter thread on both sidesSCOPE OF DELIVERYpolarizing filterprotective box

€57.00* €79.00* (27.85% saved)

EXPLORE SCIENTIFIC Filter 1.25" Orange No.21

This one really supports the detection of the dark areas on the planet Mars. The details of the clouds of Saturn and Jupiter are also so much more visible through the Filter.What ist a color Filter for and do we really need it ? Color Filters darken the light slightly, that reaches the eye or the sensor of the camera. This eliminates for instance stronger transitions. The result is that your picture turns out with more contrast which automatically shows more details.FEATURESMade from high-quality optical glassFilter glass is absolutely parallel All optical surfaces have anti reflex coatingsFilter housing from black anodized aluminumFilter threads on both ends (female/male)Multiple filters usage is possibleSCOPE OF DELIVERYColor filterProtection-case

€8.00* €14.90* (46.31% saved)

EXPLORE SCIENTIFIC Filter 1.25" Dark Red No.29

The blue/blue green light is totally blocked. The contrast between the card and the lighter zones will enormously increase. This is truly helpful when you watch Jupiter or Saturn. Or for mars, watching the poles. Starting with a telescope diameter of 10“ you can really use it effectively.What ist a color Filter for and do we really need it ? Color Filters darken the light slightly, that reaches the eye or the sensor of the camera. This eliminates for instance stronger transitions. The result is that your picture turns out with more contrast which automatically shows more details.FEATURESMade from high-quality optical glassFilter glass is absolutely parallel All optical surfaces have anti reflex coatingsFilter housing from black anodized aluminumFilter threads on both ends (female/male)Multiple filters usage is possibleSCOPE OF DELIVERYColor filterProtection-case

€8.00* €14.90* (46.31% saved)

EXPLORE SCIENTIFIC 2" Grey- Moonfillter ND-09

The neutral density filter transmits light uniformly across the entire visual spectrum. It serves as an excellent filter to reduce glare and irradiation when observing the Moon with any telescope 4"(10.2cm) and larger. The ND96 filter may also be employed in the splitting of close double stars where one of the binary pair significantly exceeds the other in brightness. Color Filter #ND96 Moon Filter (0.9 density; 13% transmission)

€24.00* €48.00* (50% saved)

Color Filter Set Essential 1,25" Red,Green,Blue,Yellow

Color Filter Set Essential is recommended for Moon & Planets from 50mm (2") Aperture Essential Set includes the following filters: BRESSER Filter Red (1,25):The blue/blue green light is totally blocked. The contrast between the card and the lighter zones will enormously increase. This is truly helpful when you watch Jupiter or Saturn. Or for mars, watching the poles. BRESSER Filter Green (1,25):The green filter is to increase the contrasts enormously between the red and the blue regions of the cloud structures on the gas planets Jupiter and Saturn. Seeing our Earth Moon through the green filter, the contrasts of each ray crater become clearly more visible.BRESSER Filter Blue (1,25):The color of light blue really supports watching the high clouds on Mars. The contrast increases. The dark red structures will be shown even darker, so this is the perfect filter for watching the big red Flecks on the gas planet Jupiter. The rings of Saturn will be accentuated, the structures of the Venus Atmosphere will be even finer. BRESSER Filter Yellow (1,25):Watching the Moon surface through the filter, the contrasts will enormously increase. Same with planet Mars. On the huge planet Jupiter, when using the filter, you can even see the contrasts between the cloud-bands and a lot more details. Starting with a telescope diameter of 8“ and a clear sight, you even get to see various details of Saturn. What ist a color Filter for and do we really need it? Color Filters darken the light slightly, that reaches the eye or the sensor of the camera. This eliminates for instance stronger transitions. The result is that your picture turns out with more contrast which automatically shows more details. FEATURESVersatile colour filter set For eyepieces and accessories with 1.25" filter thread Increase contrast on moon and planets Making object details more visibleSCOPE OF DELIVERY4pcs color filter: Red, Green, Blue, Yellow

€5.00* €9.90* (49.49% saved)

EXPLORE SCIENTIFIC Filter 1.25" Light Blue No.82A

The color of light blue really supports watching the high clouds on Mars. The contrast increases. The dark red structures will be shown even darker, so this is the perfect filter for watching the big red Flecks on the gas planet Jupiter. The rings of Saturn will be accentuated, the structures of the Venus Atmosphere will be even finer.What ist a color Filter for and do we really need it ? Color Filters darken the light slightly, that reaches the eye or the sensor of the camera. This eliminates for instance stronger transitions. The result is that your picture turns out with more contrast which automatically shows more details.FEATURESMade from high-quality optical glassFilter glass is absolutely parallel All optical surfaces have anti reflex coatingsFilter housing from black anodized aluminumFilter threads on both ends (female/male)Multiple filters usage is possibleSCOPE OF DELIVERYColor filterProtection-case

€8.00* €14.90* (46.31% saved)

EXPLORE SCIENTIFIC Filter Set 2 Moon & Planets from 100mm (4")

Filter Set 2 is recommended for Moon & Planets from 100mm (4") Aperture Set 2 includes the following filters: Explore Scientific Filter 1.25" Green No.56 - 0310262 The green filter is to increase the contrasts enormously between the red and the blue regions of the cloud structures on the gas planets Jupiter and Saturn. Seeing our Earth Moon through the green filter, the contrasts of each ray crater become clearly more visible. Explore Scientific Filter 1.25" Orange No.21 - 0310273 This one really supports the detection of the dark areas on the planet Mars. The details of the clouds of Saturn and Jupiter are also so much more visible through the Filter. Explore Scientific Filter 1.25" Yellow No.12 - 0310267 Watching the Moon surface through the filter, the contrasts will enormously increase. Same with planet Mars. On the huge planet Jupiter, when using the filter, you can even see the contrasts between the cloud-bands and a lot more details. Starting with a telescope diameter of 8“ and a clear sight, you even get to see various details of Saturn. Explore Scientific Filter 1.25" Blue No.80A - 0310264 The color of light blue really supports watching the high clouds on Mars. The contrast increases. The dark red structures will be shown even darker, so this is the perfect filter for watching the big red Flecks on the gas planet Jupiter. The rings of Saturn will be accentuated, the structures of the Venus Atmosphere will be even finer. What ist a color Filter for and do we really need it? Color Filters darken the light slightly, that reaches the eye or the sensor of the camera. This eliminates for instance stronger transitions. The result is that your picture turns out with more contrast which automatically shows more details. FEATURES Made from high-quality optical glass Filter glass is absolutely parallel All optical surfaces have anti reflex coatings Filter housing from black anodized aluminum Filter threads on both ends (female/male) Multiple filters usage is possible SCOPE OF DELIVERY 4pcs color filter protection-case

€23.00* €45.00* (48.89% saved)

EXPLORE SCIENTIFIC 1.25" UHC Nebula Filter

One of the most important obstacles for the exploration of the night sky is the brightening of the night sky by artificial lights, such as streetlights. The night sky is not really dark in the vicinity of towns or cities, which reduces the visibility of objects beyond the solar systems enormously. Depending on the type of the celestial object it is possible to increase the contrast dramatically by blocking the annoying artificial light. The EXPLORE SCIENTIFIC UHC filter uses a characteristic property of the so called emission nebulae. Those objects glow in special colours, their emission lines. Those emission lines are linked to chemical elements - in this case hydrogen at 486nm and 656nm, plus oxygen at 496nm and 501nm. The Explore Scientific UHC nebula filter blocks all other colours (and thereby nearly all of the artificial light) and only the emission line of the hydrogen and oxygen can pass the filter. The result is astonishing: suddenly nebulae are visible at locations that were completely empty without filters. In suburban skies for example the Owl-nebula M97, the Veil-nebula NGC6992 or even the bright Dumbell-nebula M27 are not clearly visible. By using this filter you can see the nebulae and their structures without problems. A must for every visual observer. The EXPLORE SCIENTIFIC nebula filters come with a individual test certificate - your guarantee to receive a premium filter.FEATURESenables the observation of emission nebulaeblocks almost the entire artificial lightonly the two emission lines of hydrogen and oxygen passes the filterWHAT'S INCLUDED1x 1.25" UHC nebula filter

€58.00*

EXPLORE SCIENTIFIC Sun Catcher Solar Filter for 150-160mm Newtonians

Explore Scientific's Sun Catcher Variable Large Aperture Solar Filters are available in many sizes to work on most telescopes from 60mm up to 10-inch Schmidt-Cassegrain and of course all Bresser and Explore Scientific Telescopes. The Solar Filter material being used is the new advanced 'Solarlite' Film manufactured by world famous Thousand Oaks Optical through years of research and development. 'Solarlite' a new solar film that has the optical quality of glass with the advantages of impregnated polymer. Perfect also for the solar astrophotographer.NOTE: All Explore Scientific Solar Equipment is rated ISO12312-2 supplied by Thousand Oaks Optical and approved for direct observation of the Sun. These solar filters are available in different sizes, the picture above shows three different sizes as an example. This is the solar filter with 127mm filter diameter.SPEZIFICATIONSSpecial objective filter for safe solar observationsISO12312-2 ratedField-stop diameter 127mmFits to outer telescope tube diameter from 150 to 280mmQuick individual match with your telescope diameterFast Setup - Easy UseSCOPE OF DELIVERY1x Sun Catcher solar filter

€41.90*

EXPLORE SCIENTIFIC Filter Set 3 Moon & Planets from 150mm (6")

Filter Set 3 is recommended for Moon & Planets from 150mm (6") Aperture Set 3 includes the following filters: Explore Scientific Filter 1.25" Light Blue No.82A - 0310265 The color of light blue really supports watching the high clouds on Mars. The contrast increases. The dark red structures will be shown even darker, so this is the perfect filter for watching the big red Flecks on the gas planet Jupiter. The rings of Saturn will be accentuated, the structures of the Venus Atmosphere will be even finer. Explore Scientific Filter 1.25" Violet No.47 - 0310272 The purple filter is perfect for watching Venus. Seeing through it, the dark clouds of the Venus atmosphere become even better visible. He also clears up the structures of the rings around Saturn. Using big openings and having a clear sight this filter is also good for watching Merkur. Explore Scientific Filter 1.25" Light Red No.23A - 0310271 The blue/blue green light is totally blocked. The contrast between the card and the lighter zones will enormously increase. This is truly helpful when you watch Jupiter or Saturn. Or for mars, watching the poles. Explore Scientific Filter 1.25" Yellow-Green No.11 - 0310269 Watching the Moon surface through the filter, the contrasts will enormously increase. Same with planet Mars. On the huge planet Jupiter, when using the filter, you can even see the contrasts between the cloud-bands and a lot more details. Starting with a telescope diameter of 8“ and a clear sight, you even get to see various details of Saturn. What ist a color Filter for and do we really need it? Color Filters darken the light slightly, that reaches the eye or the sensor of the camera. This eliminates for instance stronger transitions. The result is that your picture turns out with more contrast which automatically shows more details. FEATURES Made from high-quality optical glass Filter glass is absolutely parallel All optical surfaces have anti reflex coatings Filter housing from black anodized aluminum Filter threads on both ends (female/male) Multiple filters usage is possible SCOPE OF DELIVERY 4pcs color filter 4pcs protection-case

€23.00* €45.00* (48.89% saved)

EXPLORE SCIENTIFIC 1.25" Variable Polarizing Filter

Universally usable variable polarizing filter with a 1.25" filter thread.This variable polarizing filter allows for a continuous adjustment of the image brightness. This is very helpful to level strong differences in contrast of different observation objects individually. Particularly for lunar and planetary observations but also for solar observations this filter prevents an outshining of details.Solar observations ONLY together with an adequate solar filter !!! Particularly when a Herschel wedge is used and with large objective lens apertures the use of the variable polarizing filter can reduce the brightness of the observation object to a confortable level. The large adjustment range of 40% to 1% light transmission and the neutral grey filter effect create a comfortable and unadulterated image.The handling is very simple. The desired filtering level is set by turning the two sides of the housing against each other.A 1.25" filter thread on both sides (female/male) allow for the simultaneous use of additional colour filters.FEATURESvariable polarizing filterindividually adjustable image brightnessmade from high-quality optical glassblack anodized aluminium housing1.25" filter thread on both sidesSCOPE OF DELIVERYpolarizing filterprotective box

€58.00*

EXPLORE SCIENTIFIC Filter 1.25" Blue No.80A

€8.00* €14.90* (46.31% saved)

EXPLORE SCIENTIFIC Filter 2" Yellow No.12

€24.90*

EXPLORE SCIENTIFIC 2" O-III Nebula Filter

One of the most important obstacles for the exploration of the night sky is the brightening of the night sky by artificial lights, such as streetlights. The night sky is not really dark in the vicinity of towns or cities, which reduces the visibility of objects beyond the solar systems enormously. Depending on the type of the celestial object it is possible to increase the contrast dramatically by blocking the annoying artificial light. The EXPLORE SCIENTIFIC O-III filter uses a characteristic property of the so called emission nebulae. Those objects glow in special colours, the so called emission lines. Those emission lines are linked to chemical elements - in this case oxygen. The EXPLORE SCIENTIFIC O-III nebula filter blocks all other colours (and thereby nearly all of the artificial light) and only the two emission lines of the oxygen can pass the filter. The result is astonishing: suddenly nebulae are visible at locations that were completely empty without filters. In suburban skies for example the veil nebula NGC 6992 is almost not visible with a 200mm telescope. By using this filter you can see the nebula and its structures without problems. A must for every visual observer. The EXPLORE SCIENTIFIC nebula filters come with a individual test certificate - your guarantee to receive a premium filter.FEATURESenables the observation of so called emission nebulaeblocks almost the entire artificial lightonly the two emission lines of ionised oxygen passes the filterWHAT'S INCLUDED1x 2" O-III nebula filter

€109.00*

EXPLORE SCIENTIFIC Filter 1.25" Yellow No.12

Watching the Moon surface through the filter, the contrasts will enormously increase. Same with planet Mars. On the huge planet Jupiter, when using the filter, you can even see the contrasts between the cloud-bands and a lot more details. Starting with a telescope diameter of 8“ and a clear sight, you even get to see various details of Saturn. Minimum 3,5" aperture recommended.What ist a color Filter for and do we really need it ? Color Filters darken the light slightly, that reaches the eye or the sensor of the camera. This eliminates for instance stronger transitions. The result is that your picture turns out with more contrast which automatically shows more details.FEATURESMade from high-quality optical glassFilter glass is absolutely parallel All optical surfaces have anti reflex coatingsFilter housing from black anodized aluminumFilter threads on both ends (female/male)Multiple filters usage is possibleSCOPE OF DELIVERYColor filterProtection-case

€8.00* €14.90* (46.31% saved)

Telescope-Filters

Filters are a popular tool in the field of solar and planetary observation. They increase the contrast for certain details that are poorly or not at all to see without a filter. Basically, there are two problems with the observation: (1) over-exposure, the boundary between two regions of the observed object with different brightness "fraying" or simply blurred because the eye is overwhelmed with the contrast in bright light; and (2) adjacent areas have similar coloring, but only small differences in intensity. Both effects cause that the combination of eye-brain can no longer separate details and thus tries to show both objects as a single one.