Consider also the Optolong L-Pro Filter where LP conditions are more favourable.

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 might include the purchase of a monochrome camera, several types of narrowband filters and a filter wheel.

The Optolong L-eNhance Filter – 2″ provides an economical and practical solution for amateurs. It is a triple-band pass filter which has been designed for DSLR (digital SLR), colour CMOS and CCD 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.

Optolong believes the design of our L-eNhance filter is a technical innovation among filters. It effectively isolates the H-Alpha, H-Beta, and Oxygen III 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.

Read the Sky and Telescope Review of the Optolong L-eNhance filter. Click here!

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 trip-band L-eNhance filter in order to retain the prominent color of nebula RGB while blocking out most of light pollution. Spectrum as shown below:

The Major Emission Lines of Nebulae: H-α 656.3nm, H-β486.1nm, OIII 495.9nm, OIII 500.7nm
The Major Emission Lines of Artificial Light Pollution: Hg 435.8nm, 546.1nm, 577nm, 578.1nm, Na 598nm, 589.6nm, 615.4nm, 616.1nm

Optolong will continue to optimize the product according to actual testing, therefore the above curve is not to be used as the final product data.

Available Sizes

2” mounted and EOS APS-C clip filter are available.

Sample photos

Imaging Target： Vela Supernova Remnant
Camera : CentralDS Astro A7s (cooled at -2C)
Lens : Canon EF 300mm f/4L (non-IS)
Filter : Optolong L-eNhance
ISO : 6400
Tracker : Star Adventurer
Autoguide : none
Exp time : 1min X 81frames
w Dark, Bias frames
process with PI, PS CC
Offered by Optolong co-photographer Vincent Cheng

After a simple red structure transformation, the effect of SHO Hubble colour can also be simulated. Compared with the previous narrow band filters of Ha, SII and OIII, the L-eNhance filter is a good substitution. This one filter is multi-purpose and worth having!

Imaging Target: NGC 3372 Eta Carinae
Camera: QHY168C
Telescope: Pentax 100 SDUF II F/4
Filter：Optolong L-eNhance
Exposure:
Light Frames 15 x 240sec
Dark Frames 15 x 240sec
Bias Frames 50 x 0.001sec
Flat Frames 15 x 0.55sec
Software: SIRIL & Pixinsight 1.8.6
Offered by Optolong co-photographer Tommy Lim

More will come soon !

Package Details

• Silver cardboard box
• Plastic PP box
• Imported high pressure EVA case lining

The post Optolong L-eNhance Filter – 2″ appeared first on Modern Astronomy.

The post Optolong 2” L filter appeared first on Modern Astronomy.

Consider also the Optolong L-Pro Filter where LP conditions are more favourable.

COMPATIBILITY

LENSES:

Compatible with all EF lenses, but not compatible with EF-S lenses.

CAMERAS:

Canon EOS 7D mk II, 80D, 800D, 77D, 70D, 760D, 750D, 700D, 650D, 600D, 550D, 500D, 450D, 400D, 100D, 1100D, 1200D, 1300D and other Canon EOS APS-C bodies

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 might 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 triple-band pass filter which has been designed for DSLR (digital SLR), colour CMOS and CCD 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.

Optolong believes the design of our L-eNhance filter is a technical innovation among filters. It effectively isolates the H-Alpha, H-Beta, and Oxygen III 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.

Read the Sky and Telescope Review of the Optolong L-eNhance filter. Click here!

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 trip-band L-eNhance filter in order to retain the prominent color of nebula RGB while blocking out most of light pollution. Spectrum as shown below:

The Major Emission Lines of Nebulae: H-α 656.3nm, H-β486.1nm, OIII 495.9nm, OIII 500.7nm
The Major Emission Lines of Artificial Light Pollution: Hg 435.8nm, 546.1nm, 577nm, 578.1nm, Na 598nm, 589.6nm, 615.4nm, 616.1nm

Optolong will continue to optimize the product according to actual testing, therefore the above curve is not to be used as the final product data.

Available Sizes

1.25” mounted, 2” mounted and EOS APS-C clip filter are available now.
Other sizes will be listed when available.

Sample photos

Imaging Target： Vela Supernova Remnant
Camera : CentralDS Astro A7s (cooled at -2C)
Lens : Canon EF 300mm f/4L (non-IS)
Filter : Optolong L-eNhance
ISO : 6400
Tracker : Star Adventurer
Autoguide : none
Exp time : 1min X 81frames
w Dark, Bias frames
process with PI, PS CC
Offered by Optolong co-photographer Vincent Cheng

After a simple red structure transformation, the effect of SHO Hubble colour can also be simulated. Compared with the previous narrow band filters of Ha, SII and OIII, the L-eNhance filter is a good substitution. This one filter is multi-purpose and worth having!

Imaging Target: NGC 3372 Eta Carinae
Camera: QHY168C
Telescope: Pentax 100 SDUF II F/4
Filter：Optolong L-eNhance
Exposure:
Light Frames 15 x 240sec
Dark Frames 15 x 240sec
Bias Frames 50 x 0.001sec
Flat Frames 15 x 0.55sec
Software: SIRIL & Pixinsight 1.8.6
Offered by Optolong co-photographer Tommy Lim

More will come soon !

Package Details

• Silver cardboard box
• Plastic PP box
• Imported high pressure EVA case lining

The post Optolong L-eNhance Light Pollution Filter – EOS APS-C appeared first on Modern Astronomy.

It improves 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). As this filter is 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.

By providing maximum luminosity it reduces exposure time that is an important factor in deep sky imaging.

Main Use and Performance

Suitable for visual observation and astrophotography. The optolong 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. The L-Pro filter alone can suppress infrared wavelength, and thus can be used at ease for “L” (luminosity) image shootings with CCD cameras. Please note that light pollution filters do not completely eliminate the effects of light pollution and definitely do not increase the object’s brightness, however they increase the contrast between nebula and night sky by making the background darker.

WARNING:

Optolong filters are not designed for solar observation. DO NOT LOOK AT THE SUN WITH ANY OPTOLONG FILTER as permanent eye damage will be the result.

Technical Data

• Schott substrate material
• Glass thickness 2.0 mm (1.25”/2”/77mm)  and 1.0 mm (Clip series)
• Surface Quality: 60/40 (Refer to MIL-O-13830)
• Fine-optically polished to ensure accurate 1/4 wavefront and < 30 seconds parallelism over both surfaces
• 90% transmission of main nebula emission lines (i.e. Ha 656nm, OIII 496nm & 500nm, SII 672nm and H-beta 486nm).
• Pricision transmission of off-band, specifically the major emission lines of artificial light pollution (i.e. Na 589nm, Hg 435nm and 578nm).

Filter Cell

• Ultra-thin filter cell minimises vignetting by maximising clear aperture (clear aperture is 45mm)
• Aerometal Material
• Precise CNC Machining
• Sand Blasting Process
• Black Anodized Finish
• Extinction Treatment to Prevent Reflection
• Laser Engraving No Fading

Available Sizes

• Standard 1.25” & 2”
• Round 77mm Unmounted
• Clip Filter Series (RESTRICTED TO GERMANY! Please do not order Optolong Clip filters from Germany. We can sell only Astronomik EOS Clip filters to Germany.)

Packaging

• Plastic PP Case
• Imported High Pressure EVA Case Lining
• Silver Cardboard Box
• High Density Sponge Carton Lining

Optical Coating

• Multi-layer anti-reflection coating
• Non-cementing optical substrate coating
• 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.
• Planetary rotation system offers precision and homogeneity of coatings ensuring high value on transmission of pass-band and Optical density of off-band. (Please note, “planetary rotation system” is a type of optical coating process and does not refer to the astronomical system describing the motion of the planets in our solar system.)

The Major Emission Lines of Nebulae: H-α 656.3nm, H-β486.1nm, OIII 495.9nm, OIII 500.7nm
The Major Emission Lines of Artificial Light Pollution: Hg 435.8nm, 546.1nm, 577nm, 578.1nm, Na 598nm, 589.6nm, 615.4nm, 616.1nm

The post Optolong L-Pro 2″ Filter appeared first on Modern Astronomy.