The relentless spread of urbanization and its associated light pollution have become a growing problem for all amateurs and astro photographers. The current solutions to the problem can be expensive and frequently include the purchase of a monochrome camera, several types of narrowband filters and a filter wheel.
L-eNhance provides an economical and practical solution for amateurs. It is a dual band-pass narrowband filter which has been designed for DSLR (digital SLR), color CMOS and CCD Astrophotography Cameras. The convenience and cost effectiveness of this filter allows amateurs to image a rich selection of astronomical images, even in bright, heavily light-polluted areas. This filter is excellent for imaging object which emit H-alpha and O-III/H-beta light with near-complete rejection of all other light. For more broadband targets such as galaxies and reflection nebulae, the Optolong L-Pro is the best-suited Optolong filter.
Optolong believes the design of the L-eNhance filter is a technical innovation among filters. It effectively isolates the H-Alpha (10nm band width), H-Beta, and Oxygen III (24nm band width) nebula emission lines and achieves a maximum transmission of up to 90%. The performance of this filter delivers images that superbly control the impact from light polluted skies. This filter is excellent for emission targets such as nebulae which emit in H-Alpha and Beta, and O-III. For more broadband targets such as galaxies or reflection nebulae, the L-Pro is excellent. For maximum light pollution rejection with 7nm bands at H-Alpha and O-III, try the L-Extreme filter.
Note: The Optolong L-eNhance filters (apart from the threaded both sides version) have threads on one side to keep them very thin - 1.85mm not including the threads - they can be used with Filter Wheels, Filter Drawer System, focusers with a place to thread focal reducers internally (such as some Moonlite focusers) and camera nose pieces that fit into compression rings, but the 1.85mm filter should not be threaded into the imaging train like an adapter ring with threads on both sides.
The threaded both sides version however can be used like an adapter ring and can be threaded directly into your optical train without any additional equipment required. The threaded both sides version has a thickness of 7.6mm not including the threads. Note that this size filter will NOT fit in most filter wheels or drawers.
L-eNhance Filter Spectrum Curve
According to the characteristics of celestial body emission lines and feature of light pollution span of spectrum, Optolong specially designed and optimized dual-band L-eNhance filter in order to retain the prominent color of nebula RGB while blocking out most of light pollution.
Canon EOS-C Supported Models:
7D2/80D/800D/77D/70D/760D/750D/700D 650D/600D/550D/500D/400D/100D/1100D 1200D/1300D
The filters work with all EF lenses, but is not suitable for Canon EF-S lenses.
More details from Optolong can be found Here
Specifications
| Substrate: | B270 |
| Thickness: | 1.85mm / 10mm |
| Tpeak: | T>90% |
| Blocking range: | 300-1000nm |
| Blocking depth: | light pollution line blocking >99% |
| Surface quality: | 60/40 |
| Transmitted Wavefront RMS: | λ/4 |
| Parallelism (arcsec): |
30s |
Specifications
| Substrate: | B270 |
| Thickness: | 1.85mm |
| Tpeak: | T>90% |
| Blocking range: | 300-1000nm |
| Blocking depth: | light pollution line blocking >99% |
| Surface quality: | 60/40 |
| Transmitted Wavefront RMS: | λ/4 |
| Parallelism (arcsec): |
30s |