This 50 x 50mm 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. Is this item the same as badder Universal Alan Gee II - Telecompressor (UAG II) ?

A: No, the Alpine Astronomical Alan Gee Mark II Telecompressor is not the same as the Universal Alan Gee II - Telecompressor (UAG II). If looking on the baader-planetarium.com site, the item here would be # 2454400, whereas the UAG II is # 2454405.

Q: 2. What type of coating(s) is on this lens?

A: I contacted the manufacturer concerning your inquiry. While Voigtlander does not specify the specific coatings used on the Voigtlander APO-LANTHAR 50mm f/2.0 Aspherical Lens, they did confirm that the above lens is indeed a multi-coated lens.

Q: 3. Would this lens work well with a Leica M3?

A: Yes, the Voigtlander APO-LANTHAR 50mm f/2.0 Aspherical Lens works well with a Leica M3.

Q: 4. I have a Induro BHD0 Ballhead. Which size plate works for it? the 50 or the 70?

A: I agree that they both will work and one is just longer than the other. If you are using a big lens where the lens will mount on the ballhead instead of the camera then get the longer one.

Q: 5. is this plate fit Manfrotto 234 RC head for the monopod? is any one try one?

A: No. The Manfrotto 234 RC uses the Manfrotto 200PL plate. See B&H # MA200PL.This Black Rapid plate is the Arca-Swiss type.

Q: 6. Can this be declicked by the user? Thanks.

A: The lens like most photo not video lenses are not de-clicked. And do not have the option to do that. So, it cannot be done by the consumer to make it that way.

Q: 7. Where are the Focal Alpha 50 monitors made?

A: The Focal Alpha 50 Evo monitors are made in China.

Q: 8. I have a MeFoto Globetrotter with 60mm plate. Would the 70mm plate or the 50mm plate work better? I assume the short one would fit but not take advantage of the extra width - where the 70mm might give extra grip on the camera that would extend beyond the plate mount.

A: Thank you for your inquiry. We would recommend 50mm for cameras and 70mm for video cameras or tele lenses. We hope this has been helpful.

Q: 9. Will this work with the Breathe series CR-4 ConnectR carabiner?

A: Yes it will.

Q: 10. Is BR 50 Plate compatible with the Benro 1B1 arca-type ball head?

A: Unfortunately we cannot 100% confirm that it'll work, but agree with everyone above that it shouldn't be an issue given that our plates are arca swiss compatible overall.