This 65 x 65mm square, unmounted Baader 6.5nm f/2.0 H-Alpha Highspeed CMOS Filter from Alpine Astronomical is recommended for extremely fast optical systems from f/3.4 to 1.8, and is designed for the special filter requirements of fast optics like Celestron RASA astrographs. The filter features a Reflex-Blocker hard coating, which has been planeoptically polished, and has Life-Coat sealed edges. It is equally suitable for use with modern CMOS sensors as for older CCD camera technologies.

Optimized for CMOS, Suitable for CCD    Reflex-Blocker Hard Coated    Life-Coat Sealed Coating Edges

• 6.5nm FWHM, recommended for extremely fast optical systems from f/3.4 to 1.8
• Specially designed for the special filter requirements when used with fast optics like the Celestron RASA astrographs
• Reflex-Blocker hard coated and planoptically polished with sealed coating edges (Life-Coat)
• Blackened edges all around, with filter-lead-side indicator in the form of a black frontside outer rim
• Optimized for modern CMOS cameras, but excellent for CCD camera technologies

Related Questions and Answers

Q: 1. What is the length of this lens?

A: This lens has a focal length of 16mm and a physical length of 4.56 inches.

Q: 2. Can I add 2mm or 4mm filter guides to the filter holder like the LEE Filters holder?

A: The NiSi V7 Alpha 100mm Aluminum Filter Holder does not have optional guides to change the filter thickness.

Q: 3. Is the 82mm mounting ring compatible with general 72-82mm Step-Up Ring?

A: Yes, you can use the V7's mounting ring onto step-up rings without issue.

Q: 4. in continuation with previous question. So do i need to purchase Alpine Astronomical Baader T-2 90 Prism Star Diagonal Housing separately ?

A: It should come with everything you may need: In the Box Alpine Astronomical Baader MaxBright II Binoviewer (1.25") Carrying Case Zeiss Micro-Bayonet Mounting Adapter Limited 2-Year Warranty Alpine Astronomical Glasspath Corrector 2.6x for Maxbright/Mark V Binoviewers Limited 2-Year Warranty Alpine Astronomical Baader 2" T-2 Nosepiece Limited 2-Year Warranty I dose not come with eyepieces.

Q: 5. Would it be a problem to have a 55mm diameter base ballhead mounted on this leveling base? Would it result in some kind of instability for the base-ballhead-tripod set?

A: There would be no problem using a 55mm diameter head. The set screws are well inside the top plate for use with small heads.

Q: 6. Can I insert a 4x4 filter, a 4x6 filter, and a NiSi True Color CPL Filter all into this holder?

A: You can insert 4x4 filters, 4x6 filters, and the NiSi True Color CPL Filter in the NiSi V7 Alpha 100mm Aluminum Filter Holder.

Q: 7. Is the 82mm mounting ring compatible with the NiSi V5 circular polarizing filter?

A: No, the 82mm adapter ring is for a lens not the V5 polarizing filter.

Q: 8. the sony sensor filter stack has two separate filters. One is a clip frame, the other is glued on. Should we remove both?

A: The glued filter is the actual IR filter, I believe, but you need to contact Sony for confirmation--they don't have much information available about that.

Q: 9. can I insert a filter with 4mm thickness to this holder?

A: No, the NiSi V7 Alpha 100mm Aluminum Filter Holder only supports 2MM thick filters.

Q: 10. Will this 65mm Leveling Base be a good match for a 60.2mm Tripod Head (Acratech panoramic head)? Or should I get the one that's 60mm Ty.

A: That's fine a couple of mm over the edge is acceptable.