A premium 1.25" OIII (8NM) filter that delivers absolute the highest contrast views of many diffuse and planetary nebula. For many objects, the Baader O-III reveals a level of intricate detail that rivals the best deep sky photographs. The recommended filter for the majority of nebula, especially the Veil, Lagoon, Swan, Ring and Dumbell. With a large scope, you can even view the famous 'Pillars of Creation' in the Eagle. The Baader O-III perfectly isolates the two doubly ionized oxygen lines (496 and 501nm), through a very sharp and narrow bandpass (8.2 nm wide!, the narrowest of any O-III filter). Unlike other lesser O-III filters, the Baader O-III completely blocks longer and shorter wavelengths revealing the true teal colouration rather than a false reddish colour resulting in the highest contrast achievable.
The O-III benefits from the precision fine optically polished flat substrate, and advanced DWDM plasma assisted coatings. As a result, the Baader O-III will not degrade image sharpness or impart double images. To prevent deterioration from cleaning or exposure to moisture, some other filters even resort to sandwiching their delicate coatings between two layers of filter glass, resulting in potential blurred or double images. Contrary to myth, nebula filters are often useful at high magnifications, where image quality counts. Baader O-III filters can take high magnifications, and stars retain their pinpoint sharpness, even if the filter is used far ahead of the image plane (ie, for imaging use, or ahead of a star diagonal or binoviewer).
Simply thread the filter in to your 1.25" eyepieces or accessories with standard filter threads. This filter can be used for imaging with CCD or digital SLR cameras with a standard 1.25" thread which fits most camera nosepieces or a 1.25" T adaptor.