- Fast Shipping, Same or Next Day: You made the commitment to purchase, now you want that new item fast, we get it! At High Point all in stock orders ship within 24 hours, pending internal credit card approval.Read more ...
- Unlimited Tech Support Forever: One of the many perks of being a High Point customer is that you get access to our tech support team forever! We are astronomers at heart and truly enjoy helping fellow amateurs achieve success in the field! Read more ...
- 30 Day Return Policy: Ordered the wrong product? Don't worry, we'll take the majority of our products back within 30 days of the purchase date.We want to get you into the observing setup that bests fits your needs. Read more ...
- Guaranteed Price Match: Call or email us if you find a better price on a product! Provide a link for our team to confirm the price and within a matter of seconds you'll have a price match providing the re-seller is within the USA and authorized by the manufacturer to sell the product of interest. Read more ...
- We're Your Connection To The Manufacturer: In the event there is a warranty issue with a product purchased from High Point, we will serve as the liaison between you and the Manufacturer. The net result is faster, more attentive service from the Manufacturer and an enhanced customer experience. Read more ...
Optolong OIII CCD 6.5nm Filter - 31mm Unmounted - OIIICCD65-31U
Optolong OIII 6.5nm Filter - 31mm Unmounted
The Optolong Oxygen III 6.5nm Extra Narrowband Filter transmits a 6.5nm bandwidth of light that is centered at 500nm and drastically reduces other transmissions, including wavelengths of light that are responsible for light pollution (both artificial and natural). Like all Optolong filters that are designated as “CCD”, this OIII also blocks infrared wavelengths from 700nm to 1100nm so you don't need a separate IR-Cut filter.
This filter does wonders when imaging emission and planetary nebulae, and does a great job on supernova remnants as well. The Optolong 6.5nm Oxygen III filter can be used alone to pull out the blue-green structure in star-forming regions and emission nebulae or in conjunction with H-Alpha and SII 6.5nm filters for false color emission line images like the Hubble Space Telescope.
Due to the narrow bandwidth and high transmission rate of this filter, you will experience a major boost to contrast. The sky will be black, and when compared to a 12nm OIII, half as many stars will peep through. Extra Narrowband filters work best with cameras that have very low dark current, but will allow you to image from sites with lots of light pollution.
The Optolong 31mm Unmounted OIII 6.5nm Filter is made with Schott glass that has been multi-coated with an ion-assisted deposition technology to ensure scratch resistance and stability on the central wavelength, or CWL. This 6.5nm Oxygen III filter has been designed to be used in filter wheels that accept 31mm unmounted filters.
Quality Filter Materials:
- Schott B260 substrate material from Germany, 2.0mm thick
- Multiple layers of anti-reflection non-cementing coatings applied via electron-beam gun evaporation with Ion-assisted deposition
Optolong Filter Manufacturing Processes and Parameters
- Filter substrate is fine-optically polished to 1/4 wave and <30 parallelism over both surfaces
- Surface quality, according to MIL-O-13830, is 60/40
- 80% transmission at OIII line 500nm
- Infrared wavelength 700-1100nm cut-off
- 0.1% transmission Hg at 435nm and 578nm
- 0.1% transmission Na at 589nm
- High value transmission of pass-band and optical density of off-band is assured through Optolong’s planetary rotation system, a homogenous and precise coating procedure
- Each filter comes with a plastic case with high pressure EVA case lining
Optolong is the Astronomy Filters division of Yulong Optics, an optical filter design and processing company out of Kunming, China that has provided filters for over 700 optical companies since 1999. All Optolong filters pass European Union RoHS requirements and have been certified by TUV Rheinland and Bureau Veritas.