1.Optolong UHC Introduction
The UHC (Ultra High Contrast) broadband filter is designed to improve the visibility of various deepsky objects. By selectively reducing the transmission of wavelengths of light pollutants, specifically those produced by artificial lightings including mercury vapor lamps, both high & low pressure sodium vapor lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow). Together with the highly transparent in main nebula emission lines at OIII(496nm and 500nm), H-beta (486nm), NII(654nm and 658nm), H-alpha(656nm) as well as SII(672nm), the filter is suitable for enhancing the contrast and details for both visual and photograghic purpose at sub-rural area with heavy light pollution.
Main Use and Performance
Suitable for color CCD cameras and unmodified DSLRs.
UHC with narrower passband provides higher contrast than CLS. Thus it is more suitable for urban environment where you suffer from severe light pollution.
UHC has a substantial red passband and offer superb views for objects like the Orion Nebula (M42).
Light pollution filter do not eliminate the effects of light pollution or increase the object’s brightness. In many cases, they increase the contrast between nebula and night sky, not brightening the nebula.
WARNING: The filters of Optolong are not designed for sun observation. DO NOT LOOK AT THE SUN WITH OPTOLONG FILTER. You would be BLIND if you fail to observe the warning.
2. UHC Spectrum for Reference
How to read the chart?
▲The horizontal axis is the Wavelength in Nanometers(nm).
▲The vertical axis is transmission in %.
▲The RED line shows the transmission of the filter. The artifical emission lines are shown in ORANGE. And the emission lines from constellation are shown in GREEN.
3. UHC features
|Specifications||Applicable camera model||Applicable lens||Unit Price in US$|
|EOS-C clip||7D2/80D/800D/77D/70D/760D/750D/700D 650D/600D/550D/500D/400D/100D/1100D 1200D/1300D||
All EF lenses. But not suit for Canon EF-S lenses.
|EOS-FF clip||5D, 5D MarkII, 5D Mark III, and 6D.||All EF lenses||$115|
|NK-FF clip||D600/610, D700/750, D800/800E,D810/810A,DF||All lenses that made from Nikon, when released after 2003.||$115|
For camera clips, we only test the popular lens in market. For any other lens , feel free to contact our customer service staff. We would like to extend our sincere thanks for your support and test data.
4. Manufacturing Technology
⭐High-precision grinding and polishing to make sure the substrate parallelism is greater than 30" and the surface accuracy is better than λ/4 ;
⭐Purified water ultrosonic clearning is aim to effectively remove impurities and dust from the substrate surface.
⭐Electron-beam gun evaporation with Ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability on CWL(central wavelength) no deviation affected by temperature change; IAD not only consolidates membrane compactness, increases film firmness, but also changes vacuum coating material characteristics.
⭐Planetary rotation system offers precision and homegeneity of coating ensuring high value on transmission of pass-band and Optical density of off-band;
⭐Non-cementing optical substrate coating;
⭐Quality Control: each filters is examined by Spectrophotometer for spectrum characteristic, and Laser Interferometer for surface accuracy.
2019 NEW package
※Note：We are now in the transition from the old to the new packaging style, ship is random.
6. Optolong UHC Performance
I The Milky Way Hongkong, Cityscape shot by Vincent Cheng
II NGC2244 Rosette Nebula _by Dengyunwei
Using Optolong UHC filter
III You can see the Milky Way in Kunming City, image shot by Yule who used Optolong UHC.
See the compare.
Ⅳ M42 by Jxsky, Optolong UHC filter
V Compare iamge by astrophotographer Luocheng.
●About color: due to the influence of ambient light, color difference of the display and flash photography, the color of the product may have some color difference. Detailed color is in accordana with the final product.
●About coating: the interference filter will show different colors under different light, which is a normal phenomenon. Please refer to the material object.
●About the style: in order to improve the product, the change of design/appearance/parameters has not been updated in time. Please see the subject produce.
●About the description: the series of this product have the same material, technology and design, different sizes only, please note.