The SkyTech LPRO MAX filter is designed to improve the visibility of stars and deepsky objects, by blocking light pollution, while transmitting light from these objects.
The LPRO MAX filter has a specially tuned passband which gives an even more natural colour rendition than CLS or UHC filters. It also allows more starlight through than UHC and CLS filters for a more natural looking milky way and more natural colours in the landscape.
LPRO MAX is therefore the best choice for nightscape photography because it gives the most natural appearance.
These special coatings are difficult to make, therefore the cost is higher than most filters.
SkyTech LPRO MAX filters are suitable for both modified or unmodified Canon DSLRs because they block UV and IR light, for sharper stars.
Compatible with all APS-C sized Canon EOS cameras. Not for full frame cameras. Do not use with EFS lenses because the rear elements can strike the filter.
How this filter works: Artificial lighting such as mercury vapour lamps, both high & low pressure sodium vapour lights and unwanted natural light caused by neutral oxygen emission in our atmosphere (skyglow) are suppressed by the SkyTech LPRO MAX filter.
The filter transmits light from deepsky objects, with high transmission of ionised oxygen O-III (496nm & 500nm), Hydrogen Beta / N-beta (486nm), N-II(654nm and 658nm), H-alpha(656nm) and S-II(672nm). Additionally it blocks UV (ultraviolet) and IR (infrared) light giving sharper stars.
By selectively blocking light pollution and transmitting these desirable wavelengths, the contrast and detail of deepsky objects is greatly enhanced. Click image to see higher resolution (opens new window).
This is not an issue with most Sigma and 3rd party EF-S lenses and of course telescopes.
Features
- It can be inserted or removed in seconds. All lens functions (focus, preview screen, image stabilization) work as usual.
- If you have a telescope with short space between reducer/flattener and camera and filter wheel, a clip filter is the solution.
- It protects your sensor from dust build-up during long exposures.
Technical Data:
- Precision laser-cut housing.
- Schott glass substrate material with precision polish.
- Glass thickness 1.0 mm.
- Surface Quality: 60/40 (Refer to MIL-O-13830)
- Fine-optically polished to ensure accurate 1/4 wavefront and < 30 sec parallelism over both surfaces
- 95% transmission of main nebula emission lines (i.e. Ha 656nm, OIII 496nm & 500nm, SII 672nm and H-beta 486nm).
- 0.1% transmission of off-band, specifically the major emission lines of artificial light pollution (i.e. Na 589nm, Hg 435nm and 578nm).
Dichroic Filter Coatings:
- Multi-layer anti-reflection coating (AR Coat). Additional UV IR Blocking layer.
- Special high homogeneity coating process with electron-beam gun evaporation and Ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability on CWL (central wavelength) no deviation with temperature change.
