Product Overview
Optolong L-Pro (L-Professional) 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.
Unlike other light pollution filter UHC and CLS, L-Pro is multi-bandpass filter which offers better color balance by maximizing the transmission band. The balanced transmission allows astrophotos to be taken with minimal color cast to broadband emission objects such as galaxies, reflection nebulae and globular star clusters. L-Pro is the best choice for light pollution suppression.
Main Use and Performance
Suitable for visual observation and astrophotography.
L-Pro filter has a very low transmission reduction rate against continuous spectrum space objects, and thus is quite effective in suppressing light pollution sources when shooting galaxies, reflection nebulae and globular star clusters. The same holds true for visual star observations.
L-Pro filter alone can suppress infrared wavelength, and thus can be used at ease for “L” image shootings with CCDs.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.
New Frame of Sony-FF Clip-in Filter Specifications
| Raw material | optical glass |
| Thickness | 1.0mm |
| Blocking range | 300-750nm |
| Blocking depth | light polluton line blocking>90% |
| Surface quality | 60/40 |
| Surface shape | λ/4 |
| Parallelism | 30s |
3. Spectrum for Reference
4. New Frame of Optolong Sony-FF Clip Filter
| Sony-FF specification | L-Pro |
| Applicable Camera | A7M/ A7M2/ A7M3、A7R/ A7R2/ A7R3、A7S/ A7S2/ A7S3、A9 |
| Applicable Lenses | Full range of E-mount main and auxiliary lens |
※ Due to limit lens resource, we only test the popular lens in market. If any available lens, feel free to contact Optolong customer service staff. We appreicate for your valuab testing information.
5. How to install and remove?
►Installation
Put the camera body flat, the top of the filter "OPTOLONG" (the magnetic suction is on the back) into the body first (as shown in Figure 1), fixed by hand at the top, and then adjust the filter position, done for imaging (as shown in Figure 2).
►Removing the Filter
After putting the camera body flat, use the triangle piece aid to tilt the filter gently (as shown in Figure 1), and remove the filter once it is loosened. Be sure to avoid scratch the lens and the camera!
►Video Direction
Kindly click below image to review video about how to install and remove the filter at Optolong YouTube channel.
6. Packing:
Outer Box: silve box
Plastic Box: PP material
Lining: imported high pressure white EVA material
Shipment kit of new frame Sony-FF L-Pro clip: L-Pro filter, Trangle piece and installation instructions
7. New Frame of Sony-FF Clip-in Filter L-Pro Performance
I Milky Way by Vincent Cheng
Camera : Sony A7s mod Lens : f2 @ Tokia FiRIN 20mm ISO 6400 exp time : 20s by Vincent Cheng
II by Vincent Cheng
Camera : Sony A7s mod Lens : f2 @ Tokia FiRIN 20mm ISO 3200 exp time : 20s by Vincent Cheng
III Comparason image was shot by Arnaud Besancon
All the pictures have been realised with 5D3 Astrodon modded and Samyang 24mm F1,4 at F2, 13s exp. time,3600 isos.
All the pictures are raw,without post-process
.
IV M42 compare image by Luca Fornaciari Astrophotography
V The Horsehead Nebula©Luca Fornaciari Astrophotography
VI M31 Andromeda by Gary J Palmer
Imaged earlier in the week with a bright moon. 150 x 60 seconds processed in Pixinsight. SHARPSTAR 86mm Quad ZWO 094 PRO in ROI Optolong L-Pro filter Sharpcap
VII Here the final Image of comet 46/P Wirtanen and the Pleiades, shot by Blake Estes.
This imaging run ended up being a marathon that took about 22 hours of processing, using Optolong L-Pro filter for imaging. Its absolutely perfect!
Specifications
Specifications
- Tpeak: T>90%
- Spectrum: 380-750nm
- Optical Density: Light pollution emission is blocked 90%
- Surface Quality: 60/40
- Transmitted Wavefront RMS: ?/4
- Parallelism (arcsec): 30s
