Violet Friday Offers: Here You can expect heavily discounted items from many well-known manufacturers. If you want to buy a telescope or accessories - whether for yourself or as a gift - Violet Friday is the perfect opportunity to find a great deal and benefit from attractive discounts.
The Altair 395nm NUV filter selectively passes light of the two main Calcium wavelengths emitted by the sun: CA-K line at 393.37nm, and the CA-H line at 396.85nm.
Multi-Layer Anti-Reflection coating to reduce star-halos and reflections from camera optical window.
Batch-tested for consistency.
Ultra-flat glass by Schott Germany. 1.85mm Glass 30sec parallel, optical polish to MIL Spec. MIL-O-13830.
High quality dichroic/dielectric coatings. 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.
UV/IR block for imaging - star bloat reduction with refractors.
Precision CNC machined filter cell for strain-free mounting and freedom from tilt.
Altair Quad-Band 2" Filter for OSC CMOS, CCD and Modified or Unmodded DSLR cameras.
This is the new QuadBand V2 Coating technology which includes:
Halo suppression. We have not had any reports of halos caused by this filter in testing.
Increased blocking of UV, IR and unwanted visual range wavelengths. UV OD7 (T0.00001%) Visual OD5 (T0.001%) and IR OD4 (T0.01%) for the ultimate in skyglow blocking.
Higher transmission % of desired wavelengths Ttop 95% (Average 5% higher transmission of desired wavelengths).
Ha and Oiii wavelengths at 35nm FWHM for with less tail-off to reduce unwanted light pollution.
SkyTech Quad-Band EOS Clip Filter for DSLR cameras (including astro-modified) Narrowband Bi-Colour imaging is a growing new trend in astrophotography, especially popular in light polluted areas, or for imaging in rural areas in moonlight.
The Altair Astro Premium Oiii 6.5nm filter is designed for astro imaging of nebulae with Mono CCD or CMOS cameras, blocking light pollution by cutting out the light pollution wavelengths. The filter blocks UV IR and has an anti-reflection AR coating.
The Altair Astro Premium Sii 6.5nm filter is designed for astro imaging of nebulae with Mono CCD or CMOS cameras, blocking light pollution by cutting out the light pollution wavelengths. The filter blocks UV IR and has an anti-reflection AR coating.
The Altair Astro Premium 7nm Ha filter is designed for astro imaging of nebulae with Mono CCD or CMOS cameras, blocking light pollution by cutting out the light pollution wavelengths.