Baader ClickLock Eyepiece Clamps - from T-2 to 4.1"

What the ClickLock Clamp Is and Who It Is For

The ClickLock puts an end to thumbscrews: the barrels of your precious 2"-format eyepieces and accessories will never again be marred by thumbscrews. The clamp threads onto the focuser, visual back or adapter of your telescope and holds 2" eyepieces, diagonals and other 2" accessories in a collet instead of under the point of a screw.

It suits observers who change eyepieces often, who work with gloves in the cold, or who want one clamping system across several telescopes. Because each version carries the thread of a particular focuser or telescope family, you choose the version that matches your instrument from the list of variants on this page.

How the ClickLock Clamp Works

Simply apply gentle fingertip pressure to a knurled lever to securely retain your eyepieces and other accessories in an elegant mechanism that applies uniform pressure around the circumference of their barrels and permits interchanging them with lightning speed. In numbers: a small rotation by 20° with gentle fingertip pressure to the knurled lever is enough to securely clamp every 2" accessory.

The lever has a ratchet with acoustic and haptic display of the clamp position, so you can hear and feel in darkness, without looking, whether the clamp is opened or closed. The compression ring inside is made of thick-walled hard bronze, which keeps its shape even after many years of use and holds expensive accessories securely, without causing scratches or pressure points on your accessories.

• Lever: knurled, about 20° of rotation to lock or release.
• Ratchet: audible and tactile indication of the open or closed position.
• Collet: uniform pressure around the barrel, no thumbscrews.
• Compression ring: thick-walled hard bronze.

The Clamp Versions and the Threads They Fit

Each variant below is listed with Baader's item number, the thread it attaches to (i = female, a = male, S = Baader dovetail), its intended use, and its optical length. Choose the one that matches the thread on your focuser, visual back or adapter.

Some versions are combinations: the clamps for the Hexafoc M68x0.75 (#2956269), the Feathertouch 2.5" M63 (#2956263) and the M74 (#2956274) each consist of the M68a x 1 ClickLock clamp (#2956268) plus a Baader inverter ring (#2458236, #2458239 and #2458237 respectively).

• #2956215 1¼"/T-2i to 2" expansion, with 1¼" filter thread: 47 mm
• #2956227 2.7"a (UNF/24G), for Astro Physics, TEC and Feathertouch clamps with 2.7" female thread: 31 mm
• #2956269 M68x0.75i, for Bresser, Omegon and Explore Scientific Hexafoc focusers: 37 mm
• #2956263 M63a x 1, for Starlight Instruments Feathertouch 2.5" and TS-Optics (Photo Line) focusers: 39 mm
• #2956275 M75a x 1, for Feathertouch 3.0": 39.5 mm
• #2956241 4.1"i, for TEC 140-200 and Feathertouch 3.5" focusers: 30 mm
• #2956248 M48i x 0.75, for all male M48 x 0.75 photo threads: 36.6 mm
• #2956284 M84a x 1, for Pentax focusers: 40 mm
• #2956220 2" SC (female SCT thread), for Celestron 5" SC, 6" SC/HD, 8" SC/HD, 9¼" SC and many other SC telescopes: 47 mm
• #2956233 3.3" SCL (female), for 9¼" HD, 11" SC/HD and 14" SC/HD and other large SC and Edge HD telescopes: 40 mm
• #2956264 M64a x 0.75, for Takahashi focusers with M64 x 0.75 female threads (for example the TAK Sky 90): 40 mm
• #2956256 M56i x 1, for Celestron and Sky-Watcher focusers with M56 x 1 male thread: 30 mm
• #2956274 M74i x 1, for focusers with M74 x 1 male thread, such as Sky-Watcher Esprit 120 and 150, and TS-Optics and Omegon APO 150/1000 with Linearpower focuser: 44 mm
• #2956254 M54a x 1, for Sky-Watcher and Orion (Newtonian) focusers with M54 x 1 female thread: 30 mm
• #2956253 M54i x 0.75, for Bresser, Omegon and Explore Scientific: 30 mm
• #2956251 M54a x 0.75, for TS-Optics and Sky-Watcher: 35 mm
• #2956257 S57a ring dovetail, for Celestron and Sky-Watcher: 30 mm
• #2956242 M42i x 0.75 (T-2), for all parts of the Astro T-2 System with male T-2 thread: 36.6 mm
• #2956272 M72a x 1, for larger Takahashi focusers with M72 x 1 female thread: 41 mm
• #2956255 M56i x 0.75, for Takahashi focusers with M56 (M55.9) x 0.75 male thread: 30 mm
• #2956260 M60a x 0.75, for Vixen focusers with M60 x 0.75 female threads: 30 mm
• #2956268 M68a x 1 (Zeiss): 31 mm
• #2956258 S58 (Baader Diamond Steeltrack): 30 mm
• #2956237 2" ClickLock extension 37 mm, incl. 2" barrel
• #2956247 2" ClickLock extension 47 mm, incl. 2" barrel

Clear Aperture, Optical Length and Accepted Barrels

Every clamp version holds 2" (50.8 mm) barrels on the eyepiece side. Most versions have a clear aperture of 50.8 mm. The exceptions are the T-2 clamp (#2956242) at 42 mm, the M48 clamp (#2956248) at 48 mm and the 1¼" to 2" expansion (#2956215) at 28 mm.

Optical lengths run from 30 mm to 47 mm depending on the version, as listed above. The T-2 and M48 clamps have an inner depth of 36.5 mm and a 6.5 mm thread length. The T-2 clamp includes removable S52/M48 and M48/T-2 reducer rings, and the M48 clamp includes a removable S52/M48 reducer ring.

The 1¼" to 2" expansion (#2956215) lets 2" eyepieces mount onto 1¼" focusers or 1¼" diagonals, though vignetting may be an issue. Its 1¼" nosepiece can be removed to expose a female T-2 thread, and the T-2 thread can in turn be unthreaded to expose a 2" (SC) female thread. It can also serve as a filter holder, with a 1¼" filter thread.

Adjusting the Lever Position and Care

Once the clamp is threaded onto your telescope, the lever may end up in an awkward position. Baader's ClickLock lever adjustment manual covers this. On models with directly accessible screws, the screws at the bottom of the ClickLock are easy to reach; on some models they are covered by an adapter thread, on others they can be reached even with the clamp attached. Baader's instruction: "Simply use the included 1.3 mm Allen-Wrench-Key to loosen the screws, rotate the ClickLock into the desired position and retighten the screws firmly."

On models with hidden screws, the six screws at the bottom of the ClickLock sit beneath an expansion ring that can easily be unscrewed. Loosen them with the 1.3 mm Allen key, rotate the ClickLock into the preferred position, retighten the screws firmly and reattach the adapter ring. The manual is in the Downloads tab.

• Use the 1.3 mm Allen key named in the manual.
• Loosen the screws, rotate the ClickLock, retighten the screws firmly.
• On hidden-screw models, remove and then reattach the expansion ring.

Combinations with Baader Diagonals and Adapters

Several parts work with these clamps. The 2" to 1¼" ClickLock Reducer (#2956214) mounts in a 2" ClickLock clamp and is shown in the 2" SC-ClickLock visual back (#2956220); it holds 1¼" eyepieces and has a 2" filter thread and a T-2 photo thread inside. The 2" ClickLock dielectric star diagonal (#2956100) has its own 2" ClickLock clamp and a mirror housing with integrated 2" SC threads.

For a Takahashi Mewlon, the M72 clamp (#2956272) needs the additional Mewlon Adapter M71/M72 (#2558231). The S58 version (#2956258) is the clamp for the Baader Diamond Steeltrack, and the 37 mm and 47 mm ClickLock extensions (#2956237, #2956247) each include a 2" barrel.

Holding Heavy Accessories

Rotating the locking collar by only 20 degrees holds an eyepiece so securely that it is possible to vertically suspend a massive (57-pound) C-14 tube assembly. The collet was extensively tested, and its durable and robust construction will provide years of trouble-free service.

Baader does not give a payload rating for cameras or binoviewers, so check the weight of your own setup against the clamp you choose.

Build and Weight

The compression ring is thick-walled hard bronze. Weights depend on the version: from 0.12 kg for the M54a x 1 clamp (#2956254) to 0.32 kg for the 4.1" clamp (#2956241). Outer diameters range from 68 mm on most versions to 112 mm on the 4.1" clamp; the full figures per version are in the Specifications tab.

Getting Started

Setting up the clamp takes a few minutes.

• Check the thread on your focuser, visual back or adapter, and choose the matching version.
• Thread the ClickLock onto it.
• If the lever sits in an awkward position, adjust it as described in Baader's lever adjustment manual.
• Open the clamp, insert the 2" barrel of your eyepiece or accessory, and turn the knurled lever about 20° until the ratchet shows it is closed.
• To release, turn the lever back and remove the accessory.