Dovetail Plates, Tube Rings & Mounting Adapters

Plates, rails and tube rings: The connection between optics and mount

The coupling between the optical tube (OTA) and the mount is one of the most important mechanical points of a telescope. If this joint is not rigid enough, vibrations occur that make visual observation difficult and astrophotography impossible. In this category you will find the hardware needed to secure, balance or extend your telescope. At Telescoop.nl we supply components from Bresser, Explore Scientific and Omegon that meet international standards.

Whether you have a larger barlow lens uses or mounts a tracking camera: the base must be immovable.

Dovetails and rails: Vixen vs. Losmandy

A dovetail (dovetail) is the metal rail that sits at the bottom of the telescope and slides into the mount's clamp. There are two systems used worldwide:

• Vixen-style (45mm): The standard for lighter telescopes, such as compact refractors and smaller Newton telescopes. Our rails of Omegon and Bresser are made of solid aluminum and provided with screw holes for universal mounting.

• Losmandy-style (3 inch / 75mm): For heavy instruments and astrophotography, the wider Losmandy rail of Explore Scientific the norm. The larger bearing surface minimizes the chance of deflection, which is crucial during long exposure times.

Tube Rings (Mounting Rings)

Not every telescope has a fixed rail. Many models have tube rings used. These rings clamp around the optical tube and are then screwed onto a dovetail.

1. Diameter: It is important that the rings fit the outside diameter of your telescope exactly. We carry sizes for the most common tube diameters.

2. Accessory mounting: Many tube rings from Bresser and Explore Scientific have extra threads on the top (often 1/4″ photo thread), so you can place a camera or tracking scope on top of the telescope.

Clamps, Saddles and Adapters

The transition from one standard to another often requires specific components. You can find these under telescope-accessories/mountings/mounting-accessories/plates-rails-and-tube-rings/.

Within the mount accessories clamps and adapters are the parts that make your system modular:

• Mounting Saddles: The clamp on the mount into which the rail slides. We have dual clamps that accept both Vixen and Losmandy rails.

• Mounting Adapters: Do you have a telescope with a Vixen rail but a mount with a Losmandy clamp? With an adapter from Omegon bridge this difference without losing stability.

What do you look for when purchasing?

When choosing the right mounting hardware, three technical points are key:

1. Carrying capacity: A rail that is too light under a heavy telescope can become twisted. Always choose a rail that matches the weight of your tube including all accessories.

2. Length of rail: A longer dovetail gives you more room to slide the telescope forward or backward in the clamp. This is necessary to balance across the latitude axis.

3. Hole pattern: Check that the holes in the rail match the connections on your tube rings or the underside of your telescope.

Advice for your astro setup

Looking for a sturdy Losmandy rail from Explore Scientific for a large reflector, or do you want a compact Vixen adapter from Omegon for your travel telescope? At Telescoop.nl, we have the experience to determine which joint is most stable for your particular instrument. We make sure the mechanics are right so your optics can perform optimally.