77mm H-alpha + Visible Astrophotography Lens Filter – 20% Off Clearance Item
Clearance filters will arrive with cosmetic defects. Examples of a cosmetic defect are light surface scratches, smudged AR coating, or other small defects in the filter glass itself. This issues will have very little to no effect whatsoever on image quality. However, due to their appearance, they can not be sold as brand new, unused items.
We now offer the same H-alpha Sulfur II glass used for our astrophotography conversion service as an external lens filter to be used with Full-Spectrum or Two-Spectrum converted cameras. This H-alpha astrophotography filter has a similar transmission to our IR/UV cut Hot Mirror Filter, but with expanded spectral response that covers the H-alpha and sulfur II emission lines (See transmission curves below). Now, there is nothing you can’t do with a full-spectrum camera. When used with a converted camera, these filters will provide a greater than 4 fold increase in sensitivity in the H-alpha line compared to a stock camera, and a greater than 6 fold increase in sensitivity in the sulfur II line. Our H-alpha Astrophotography filter comes standard with our Pro Slim filter rings.
- IR and UV blocking filter with enhanced h-alpha & sulfur II transmission
- Anti-reflective (AR) coated to increase light-transmission and reduce flare and ghosting
- Slim filter ring for reduced vignetting when using wide angle lenses or when stacking filters
- Front and rear threaded unlike other slim filters
- 6061 aircraft aluminum construction for a light and strong ring
- Teflon coated threading for easier installation and reduced seizing
- Finger grips for easier filter removal