MEADE 911X O-III Nebular 2 Filter Rear Cell Thread Start Price USD 128.00 Current Price USD 128.00 Time Left - Bid Count 0 Buy It Now Price - Reserve Price - Start Time Friday, September 05, 2008 End Time Friday, September 12, 2008 Location Staten Island, New York See more about 'MEADE 911X O-III Nebular 2 Filter Rear Cell Thread' Description smartastronomy Store 2'' Meade® Series 4000 Oxygen-III Nebular Filters made in JAPAN For the observation of diffuse emission and planetary nebulae. Meade Oxygen-III (O-III) nebular filters provide an extraordinary level of nebular filtration on diffuse and planetary nebulae. Observations of these nebulae in a city environment with the O-III filter often yield more image contrast than observations of the same objects in a dark-sky setting without the filter. Wavelength vs. Transmission graph of the Meade Oxygen-III Nebular Filter. The O-III filter transmits high percentages of the Oxygen-III wavelengths while attenuating other undesirable wavelengths. The O-III filter extracts more than 80% of the light emanating from the two oxygen-III spectral lines at 496 and 501nm. Objects such as the Omega (Swan) Nebula (M17) in Sagittarius, the Orion Nebula (M42) in Orion, the Helix Nebula (NGC 7293) in Aquarius, and the Eagle Nebula (M16) in Serpens are revealed in dramatically increased detail. Meade 60-layer interference coating technology isolates the desirable O-III lines, while attenuating other spectral lines virtually to zero. As with Meade Narrowband Filters, the O-III Filters are complements to other Meade nebular filters; the effectiveness of each filter type is highly dependent on the physical characteristics of the particular nebula being observed.  Place a Bid!