Baader Planetarium 3.5/4nm Ultra-Highspeed-Filter Set CMOS-Optimized (H-alpha / O-III / S-II)
Baader Planetarium 3.5/4nm Ultra-Highspeed-Filter Set CMOS-Optimized (H-alpha / O-III / S-II)
Focal Ratio
Filter Size
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Product Description
Note: this filter has multiple size & focal length options. See below for details.
This new generation of Baader CMOS-filters features:
- Increased contrast
- Ever more narrow passbands
- Reflex-Blocker™ coatings, for largest ever freedom from halos, even under most adverse conditions concerning aux-optics
- FWHM on each filter category carefully designed to allow for 1:1:1 exposures, matched for typical CMOS quantum efficiency and s/n ratio
- Identical filter thickness to existing standards, with utmost care for parfocality
- Blackened edges all around, with filter-lead-side-indicator in the form of a black frontside outer rim, to additionally eliminate any reflection due to light falling onto the edge of a filter
- Each filter coated individually, with sealed coating edge (NOT cut out of a larger plate with coatings left exposed, read more)
- Life-Coat™: evermore hard coatings to enable a non-aging coating for life - even in a most adverse environment
Sizing & Focal Ratio SKUs Table
f/2 (for <f/2.3) | f/3 (for f/2.3-f/3.4) | f/4 (for >f/3.4) | |
1 1/4" (Mounted/Round) | 2961680 | 2961640 | 2961670 |
2" (Mounted/Round) | 2961683 | 2961643 | 2961673 |
31mm (Unmounted/Round) | 2961681 | 2961641 | 2961671 |
36mm (Unmounted/Round) | 2961682 | 2961642 | 2961672 |
50.4mm (Unmounted/Round) | 2961684 | 2961644 | 2961674 |
50mmx50mm (Unmounted/Square) | 2961685 | 2961645 | 2961675 |
65mmx65mm (Unmounted/Square) | 2961686 | 2961646 | 2961676 |
What's in the Box
Specifications
Manufacturer | Baader Planetarium |
Net weight (kg) | 0.18~0.26 |
Size & Shape |
Seven Options Available:
|
Suitable for f/ratio |
Three Options Available:
|
Transmission Range | H-alpha / O-III / S-II |
Filter Thickness (without cell) |
|
HBW (Half Bandwidth) | 3.5 nm (H-alpha) / 4 nm (O-III / S-II) |
CWL (Central Wavelength) | 656.3nm / 500.7nm / 671.7nm |
AR-Coating | Reflex-Blocker™ hard coated, planeoptically polished |
Special Features | CMOS-optimized with Life-Coat™ |
Filter size | Multiple Size Options Available |
Filter Usage | CMOS, CCD, H-alpha, O-III, S-II |
Single or Set? | Filter-Set |
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