2" O-III telescope filter

O-III telescope filter astounding high light transmission brings better views of deep-sky-objects, BV assessed 24years factory

 Kson supply 1.25" and 2" O-III telescope filter

OIII filter has been very specifically designed for the visual observation of gaseous and planetary nebulae. The extremely narrow pass band of the two OIII lines brings a substantial contrast gain to these lines even under best observation conditions. On faint super nova remnants and faint planetary nebulae the OIII filter will often make the difference as to whether the object can bee seen or not!

Main use

Since enough light must be available to make use of the OIII filter it is best to use this filter with apertures of more than 6" (150mm). Smaller instruments do not gather enough light for meaningful and satisfying astronomical work. However, please note: Many experienced Deep Sky observers, with apertures of more than 10" (250mm), prefer using the OIII filter instead of the more versatile UHC filter. Due to the high optical quality of the OIII filter substrate you will see the same needle-sharp stars as you would from your regular telescope.

Suitability

Visual observation (dark skies): Verry good, huge contrast enhancement at O III-emission nebulasVisual observation (urban skies): Verry good, huge contrast enhancement at O III-emission nebulasFilm photography: It depends, very long exposure timeDSLR photography (original): Verry good, huge contrast enhancement at O III-emission nebulasDSLR photography (astro modified): Verry good, huge contrast enhancement at O III-emission nebulasDSLR photography (MC modified): Good, when used with an additional IR-block-filterWebcam / Video (Planets): UnsuitableWebcam / Video (Deep Sky): Reasonable, if light pollution is a big problem and OIII Objects are beeing observed

Technical Data

Transmission of nearly 100% of both OIII linesComplete blocking of all disturbing wavelength coveragesThe ideal filter for telescopes 10 " (25cm) and largerMain operational use: Planetary nebulas & super nova remnantsNo moisture-sensitivity, no aging, and totally scratch-proofExcellent carrier material - substrate is optically polished. The optical performance (resolution & contrast) of your telescope is not reduced in any way by the filter.Parfocal with other Astronomik filtersGlass thickness: 1mmCompletely resistant against high humidity, scratches and aging effectsDiffraction limited, the filter will not reduce the optical performance of your telescope!Astronomik filters are delivered in a high-quality, long lasting, filter box