Binoculars Collimation Problem

Recently, I have experienced a frustrating situation, which almost all binocular owners face, the collimation problem. And once the binoculars are out of collimation, they give stupid double images which cause immediate headache while observing.

I picked my binoculars up from Karachi. Brother Abbas from Karachi Astronomers Society had fixed it after it was damaged.


An image of a house from a miscollimated binoculars


Travelling back to Hyderabad, I noticed that the sky was so dark and clear since it was miles away from city lights. Asked father to stop the car so I could test the bino. As soon as I saw through it, I immediately realized that the binoculars had went out of collimation once again due to Super Bumps on Super Highway.

This turned me off totally for the rest of journey. As soon as I reached back home, I hit the internet in search of collimation guides. Found a few but I was so tired that I thought to give it a try next day.

Next day I went up the roof in daylight and tested the binoculars at a far away person sitting on the roof of a 6 floor building. He was appearing double. Then I started tampering with the Porro-Prism screws of the binoculars, tested it again and again but couldn’t get the satisfaction, so left the work until the night.

At night, I again picked up the screw driver and started turning the screws around. After about 15 minutes of frustrating work, the Double Jupiter finally merged into one image and gave a crisp view. This was the first ever time I saw Jupiter’s Galilean moons.

Collimating a binocular is a super easy but a frustrating technique, as you have to test the binoculars with every drive you give to the screws.

Clear Skies.


    • Rakesh Kumar on November 2, 2010 at 6:57 pm
    • Reply

    First of all which one of the pair to collimate ?
    Set the bino on a tripod preferably in daylight.Set the bino horizontally in a room towards the sky light. Then look thru the Objective end from a distance. You will see the eyepeice holes as a tube. They should be concentric bang in the center of the objective lens. If they are not they are uncollimated. More shifted more uncollimated. so ideally instead of trying to merge the images one should try to bring the eyepiece holes as seen from the objective end to the center of the objective lens.

    1. Dear Rakesh,

      Both of the methods work fine. The method I have explained was tried by me at night and hardly took 15 minutes of my time and now I have a perfectly collimated binoculars.

      Determination of the pair was not a big problem.

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