Apart from air turbulence, the brightening of the night sky is the greatest barrier to observing faint objects beyond the solar system. Due to streetlamps and other artificial lighting, the sky in urban areas is no longer properly black. As a result, the contrast and thus the perception of deep-sky objects also suffer. However, depending on the type of celestial object, it is possible to filter out some of the interfering light making it easier to photograph the objects.

The EXPLORE SCIENTIFIC H-Alpha filter uses the characteristic of the so-called emission nebulae. These objects glow in certain colors, the so-called emission lines. The emission lines are associated with certain chemical elements - in this case the red glowing hydrogen. This filter blocks all other colors (and therefore almost all artificial light) and lets only the emission lines of hydrogen through. Especially the interfering light of mercury and sodium vapor lamps is effectively blocked. The effect is amazing: suddenly, nebulae become visible on the photos in locations which appear completely empty without the filter.

The EXPLORE SCIENTIFIC H-Alpha Nebula Filter has been developed for astrophotography exclusively. Especially in slightly light-polluted skies many emission nebulae only become visible and are shown in full expanse on astrophotos when using this filter. The H-Alpha nebula filters make astrophotography near the city possible and the use leads to amazingly good image results despite the existing light pollution. A must for every urban astrophotographer.

The EXPLORE SCIENTIFIC nebula filters are delivered with an individual test report - so you can be sure to get high quality filters.
 
FEATURES
H-Alpha filters are used for astrophotography exclusively
Allows photography of emission nebulae that glow in the light of red hydrogen
Many of these emission nebulae are only visible in their full expansion in photos taken with this filter
Blocks almost all artificial light, especially from mercury and sodium vapor lamps
Only allows the emission line of red hydrogen to pass through
Transmission bandwidth: 12 nm
Allows more contrast and detail for all urban astrophotographers
Ideal for use near cities, in slightly brightened skies
Individual test certificate included to guarantee you receive a premium filter
 
HIGHLIGHT
High-quality EXPLORE SCIENTIFIC H-Alpha filter
Only lets pass the emission lines of hydrogen
Absorbs all other emission lines and almost all artificial light
Ideal for use near the city, with slightly lightened skies
Band pass width: 12 nm
Better contrast and more details achievable for urban astrophotographers
Blocks almost all light from mercury and sodium vapor lamps
Many of the red glowing emission nebulae are only visible in full expansion on photos taken with this filter
In spite of the existing light pollution amazingly good image results are possible
Individual test certificate included to guarantee you receive a premium filter
 
SCOPE OF DELIVERY
1x 1.25'' H-Alpha Nebula Filter
Box Case
Certificate