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1.25″ H-beta Nebula Deep Sky Filter Dark Nebulae AstronomyClick images to enlargeDescription1.25″ Hydrogen-betaAstronomical Nebula Filter,c/wstorage Case.This top quality 1.25″ H-beta astronomical nebula filter is in excellent, lightly used condition. It comes complete with a foam-lined storage case as shown. Useful on larger apertures for finding elusive dark nebulae.
A Hydrogen-betafilter is an interference “line” filter designed for use on certain types of faint emission nebulae. These filtersallow the prominent emission lineof H-beta and O-III to pass, while excluding many other wavelengths. The peak is in the blue-green part of the spectrum. This filterwill significantly reduce the residual sky glow from light pollution, natural airglow, and other non-desirable light sources.This is achievedthrough a very high transmission at the H-beta OIII wavelengthscoupled witha very narrow passband width, which is typically less than 23nanometers FWHM (Full Width at Half Maxima). This can make some faint nebulae a lot easier to see than they would be without a filter in place.
They tend to work the best under dark or semi-dark sky conditions, as the eye must be well dark-adapted to get the most out of the filter’s performance. However, with some shielding from local light sources, theycan be successfully usedin urban viewing locations.I’m happy to combine postage. Please see my otherastronomy relateditemslisted!Any questions, please feel free to ask!Terms of SaleAll items are described as accurately and honestly as possible. Returns will be accepted and a full refund (including postage) will be given should the item be not as described. Such a decision will have to be agreed with the seller first in those circumstances. If the item is found to be ‘as described’ but was purchased in error, returns are accepted,and the purchase cost of the item will be refunded. In such situations, no postage refunds will be issued.Get images that
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Category: Cameras and Photography:Telescopes and Binoculars:Telescope Parts and Accessories:Filters
Location: Leeds, West Yorkshire