|
Hydrogen-alpha |
Sulfur-II |
Oxygen III |
|
|
FWHM |
2.5nm +0.3/-0.1nm |
2.5nm +0.3/-0.1nm |
2.5nm +0.3/-0.1nm |
|
CWL (Central Wavelength) |
656.3nm |
672.4nm |
500.7nm |
|
Peak Transmission |
95% |
95% |
93% |
|
Blocking |
≥OD5 |
||
|
Filter Thickness |
2mm+/-0.05mm |
||
The main features and application:
- High transmittance （Ha/SII≥95%，OIII≥93%）and the narrow FWHM 2.5nm +0.3/-0.1nm to maximize contrast;
- Flat-top spectrum minimizes the loss in transmission due to the Center Wavelength (CWL)-shift;
- Out of band blocking specification is designed to OD5 (0.001%) to block interference from other wavelengths and minimize halos around bright stars;
- Made of quartz glass, excellent durability and thermal stability, better fracture resistance and scratch resistance, improved coating resilience to cleaning;
- Filters are resistant to scratches；
- Identical filter thickness to existing standards and double-sided fine polishing , with utmost care for parfocality;
- The SHO 2.5nm Ultra filters are recommended for use in optics with a Focus Ratio of ≥ f/3.5 for best optical performance;
- 100% of production are scanned individually, all transmission and blocking (OD) data in the box are actual, measured spectra and transmission；
- All Antlia filters are coated to the edge of the substrate and unmounted narrowband filters are edge blackened to eliminate internal reflections from stray light；
- Warranty: 3-years against delamination.
Spectrum Curves:
Filter Ring:
Antlia standard ring:1.25’’ (M28.5*0.6)，2’’(M48*0.75)
Ultra-thin filter cell to minimize vignetting by maximize possible clear aperture
Black Anodized Finish
Laser Engraving No Fading
Not Recommended:
Solar imaging
Night visual observation
Not Permitted:
DO NOT LOOK AT THE SUN WITH THIS FILTER
Serious eye damage will result if you fail to observe the warning.