OnAxisLock 31,8mm eyepiece holder

FAST SHIPPING with express courier

OnAxisLock 31,8mm eyepiece holder


OnAxisLock 31,8mm eyepiece holder fits into 50,8mm connection like the ones of the most common focusers.

OnAxisLock is the accessories locking system that, compared to those using normal screw, offers a greater clamping force, avoiding any possible flexure (so it's perfect for astrophotography), it does not damage the connected accessory and it perfectly keeps the optical axis of the telescope. All this thanks to a new locking device with double ring: just rotate manually the appropriate outer ring (designed to allow an easy grip, even with gloves) and you will get a perfect closure!


We do not ship PrimaLuceLab products to UK or USA, you can order to one of our UK or USA dealers.


Using photo accessories such as heavy digital reflex or cooled CCD (often even with filter wheels), it is crucial that there is no flexing when joining them into the telescope focuser. This also applies to visual use with large diagonals and wide-field oculars (which are often very heavy).

For this reason we have created the OnAxisLock 31.8 mm eyepiece holder that replaces the classical screw closure with a ring-locking device. This allows you to perfectly block your accessory, just rotating the outer ring (red): a special double inner ring grips accessories with a uniform pressure.

OnAxisLock is designed to keep perfectly in axis the accessories inserted in the focuser: you will be 100% sure that the sensor of your camera will be perfectly centered on the optical axis of the telescope.


OnAxisLock 31.8mm eyepiece holder inserted into the focuser of AIRY APO104T telescope


OnAxisLock 31,8mm eyepiece holder fits into 50,8mm connection like those of the most common focusers.

It's perfect for CCD cameras equipped with a 31.8mm dia. nose, but we do recommend it even for visual use with 31.8mm dia. diagonal mirrors and/or eyepieces. The particular locking mechanism also prevents damaging the inserted accessory because the pressure is distributed uniformly in the barrel. The classic screw closure, working on a much smaller area,  generates a mechanical stress that can easily ruin the barrel.


The special design of the outer ring has been developed to allow you to lock the accessory with ease, even when wearing gloves. This way you can be sure to safely lock your CCD camera or your eyepiece even in bad weather conditions. 

EAN code


No reviews

Related products