- Stock: In Stock
- Model: ST22021703
- SKU: ST22021703
Specifications:
Size | 2 Inch |
Thickness | 2.0mm |
Surface Quality | 60/40 (Refer to MIL-O-13830) |
Fine-optically polished | Ensure accurate 1/4 wavefront and <30 seconds parallelism over the both surfaces |
Transmission | 90% |
Thread | M48*0.75 |
Features:
- Suitable for visual observation on most emission nebulae, planetary nebulae and supernova remnants
- Suitable for viewing on bright nebulae like M42 Orion Nebula in heavy light pollution
- Use with a large aperture telescope under clear and dark viewing conditions with good seeing
- Narrowband filter do not eliminate the effects of light pollution or increase the object’s brightness. In many cases, they increase the contrast between nebula and night sky, not brightening the nebula.
The Major Emission Lines of Nebulae:
H-β486.1nm OIII 495.9nm OIII 500.7nm H-α656.3nm
The Major Emission Lines of Artificial Light Pollution:
Hg 435.8nm 546.1nm 577nm 578.1nm
Na 598nm 589.6nm 615.4nm 616.1nm
Package includes:
1 x OPTOLONG filter
WARNING:
The filters of Optolong are not designed for sun observation. DO NOT LOOK AT THE SUN WITH OPTOLONG FILTER. You would be BLIND if you fail to observe the warning.
