Instadjust Info on Radians & Nagler Type-4 Eyepieces
Changing the Instadjust Tension on the Radians
  1. With the eyepiece standing upright on a table, unscrew the engraved name ring from the Instadjust housing.
  2. Hold the chrome barrel and slide the Instadjust housing up and off the eyepiece. Be careful that the spring wire within the housing doesn't fall out and hit the eyelens.
  3. With the housing clear of the eyepiece, remove the spring wire from its groove. A toothpick may help you extract it.
  4. To tighten the Instadjust tension, squeeze the diameter of the wire slightly smaller. To loosen the Instadjust tension, stretch the diameter slightly larger. Small amounts make a big difference in feel.
  5. Place the wire back in the groove in the Instadjust housing. It will float.
  6. Reinstalling the housing isn't difficult, but takes some finesse. Slide the housing over the eyepiece. Tilt the housing slightly to try to catch the two ends of the wire under the top lip of the eyepiece. Then, at 180 degrees around from the open end of the spring wire, press the wire into the groove while gently pushing the housing down. Once you get it in the top position, you should be able to slide the Instadjust down the eyepiece barrel freely.
  7. Thread on the name ring, which acts as the stop.

If you have any questions, please call Tele Vue Optics.

Instadjust Motion Tightened on Nagler Type-4 Eyepieces

All Type 4 Naglers (12mm, 17mm, and 22mm), delivered since June, 2000, have been fitted with a new type "name-ring" with an internal friction strip to tighten and further smooth the Instadjust motion. (Some users found the original motion too loose.)

We are making the new ring available to users (in the U.S.). Call us for details.

The new ring simply threads on in place of the original name-ring. You can tell the difference by noting the smooth black finish inside the older ring, since it lacks the internal friction strip of the new style.

Tele Vue is always working to improve products whenever possible and to make improvements retrofittable where practical.