The 36mm, unmounted Baader 3.5/4nm f/3 Ultra-High-Speed Filter Set from Alpine Astronomical features three precision-grade filters recommended for extremely fast optical systems from f/3.4 to f/2.3. The set includes H-alpha, O-III, and S-II filters optimized for use with CMOS sensor cameras and suitable for CCD sensors.

3-Filter Set: H-alpha, O-III, and S-II    For f/3.4 to f/2.3 Optical Systems    CMOS-Optimized and Suitable for CCDs    Reflex-Blocker / Life-Coat    Blackened Edges

3.5/4nm half width (to harmonize exposure time of H-alpha with O-III / S-II), recommended for extremely fast optical systems from f/3.4 to f/1.8

Specially designed for filter requirements of highly opened optics, such as the Celestron RASA astrograph

Enables high contrast even with the strongest light pollution to minimize the size of stars and make nebula details accessible which is useful under a Bortle 9/8/7/(6) sky

Reflex-Blocker hard-coated and optically polished, with Life-Coat sealed coating edges

Blackened edges all around, with a filter front indicator in the form of a black outer edge on the front

Optimized for CMOS sensor cameras and suitable for CCD sensors

FWHM on each filter category is 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 attention given to parfocality in the design

Related Questions and Answers

Q: 1. I have some late 80's early 90's Minolta AF A-mount lenses , like the 100mm 2.8 / 50mm 1.4 / and 500mm 8. Would these autofocus on the sony 7rii in Video Mode? Thanks

A: A to E Mount adapters can give you autofocus. https://bhpho.to/2qaXWtu

Q: 2. Are these wheels compatible with Kupo High Roller Stand (14') BH #KUKS300112 MFR #KS300112?

A: The Kupo 8" Pneumatic Wheel with Square Speed Adapter (Set of 3) BH #KUKS941412 is suitable for use with the BH #KUKS300112.

Q: 3. What kind of modificatiom is required for Summicron 50mm? Also, does this work with Leica APO 2x teleconverter?

A: The Metabones Leica R-Mount Lens to L-Mount Speed Booster ULTRA 0.71x will work directly with the Leica Summicron R 50mm F/2 Lens and the Leica R APO 2X Teleconverter. Keep in mind this is designed for APS-C L-mount cameras.

Q: 4. Will these tubes work on a 7D Mark II and the EF100mm f2.8L MACRO IS USM lens?

A: These are totally manual extension tubes. Any lens you use them with must have manual focus and manual aperture control. If the lens does not have an aperture ring that you can adjust with your fingers (not the camera dial) you will not have any control of exposure other than shutter speed. No aperture control means not control of DOF which makes them useless. I am not a Canon shooter but I don't believe that lens has any manual aperture capability.

Q: 5. Does this adapter power the servo zoom thru the camera? Using an FS7 & Fujinon 20-120

A: No, It won't power anything thru the camera. It's just a passive adapter.

Q: 6. are they compatible to the canon SL1?

A: Yes, these extension tubes are compatible with the Canon EOS Rebel SL1 camera.

Q: 7. Does this item work well with PXW-FS7 and Nikon F and G lenses?

A: I bought it to use on a Sony FS100 with my Nikon lenses. I've not put it through a great workout yet but I have used it several times with no problems. It's very well built, it feels very snug and secure even with heavier lenses, though it still attaches (or removes) to the camera and lenses smoothly. As for F&G lenses, I've only used it with the F mounts, but I just stuck a G on there and looked, it operates the aperture on it as well. The aperture ring on the Metabones has no click stops, so it rolls smoothly with just a tiny bit of resistance (good). I've also bought one for using on a GH-4 which is a micro 4/3 mount. I'd recommend them.

Q: 8. Does this adapter can be use on Sony a77 and Sony a99 ii for Sigma 800mm F-mount with AF? If not what adapter do you suggest to be able to use this camera with AF?

A: No, the Metabones Nikon F-Mount Lens to Sony E-Mount Camera Speed Booster ULTRA will not work with the Sony A99 or the A77: https://bhpho.to/2dRc0U1

Q: 9. Can I use this with the sigma 18-35 which is an APS-C lens? Will it cause vignetting?

A: Recently did this combo with a metabones adapter on a sony a7rii camera. There was some vignetting at 18mm, but it goes away as you get closer to 35mm. Also tried it with a regular novoflex adapter. Did not vignette but you do get some cropping. Will be using both arrangements in the future.

Q: 10. Is this Metabones Nikon F-Mount Lens to Sony E-Mount Camera Speed Booster ULTRA compatible to Sony A7R camera?

A: No it is not. It is only compatible with APS-C NEX model cameras.