binocular repair: DIY

Binoculars are basically two telescopes in a single device. But to get a solid, crisp, and full image in a pair of binoculars, it should be properly collimated. Collimation refers to the perfect alignment of the prisms and the lenses. But oftentimes, this alignment gets disintegrated due to rough handling and as a result, your binoculars produce poor quality or overlapping photos. Though top rated binoculars are less prone to these issues eventually they might start malfunctioning. These conditions often cause headaches, eye strain, and fatigue. Binocular repair calls for attention if you have issues seeing any object properly through the lenses. The manufacturers keep the options available for users to repair or adjust the binoculars. Stay with us to know how to repair binoculars at home.

How to Repair Binoculars?

There are tilt setscrews on each of the binocular barrel. These are adjustable, so you can change the prism position until your binocular pair produces normal and aligned images. If the pair has only a minor issue, working on the setscrews usually does the trick. Binoculars can have several problems and you can repair almost all of them all by yourself. These are the main binocular repair parts:

  • Prism
  • Lenses
  • Focus Knob

How to Repair the Prism Alignment in Binoculars?

This is one of the main binocular parts that often need repair. Follow our step-by-step guide to repair the prism alignment in your binocular. Binoculars and monoculars are fundamentally the same so you can apply these techniques to repair monoculars as well.

1. Placing the Binocular

Take your binoculars out in the daylight. Always keep your binocular repair manual with you so you can look at it whenever in confusion. Aim for a prominent edifice about 100 yards away with horizontal and vertical lines. Make sure to lie the binoculars on a solid and flat surface. The binoculars should face the edifice horizontally.

Stabilize the binoculars by mounting them on a binocular tripod. Make sure the positioning enables you to have a central field of view.

2. Horizontal Collimation

Rest your eyes for some time and look out for a unique vertical line on the edifice. Now, close one eye and look at the line for a few seconds. Then, close that eye and look with another eye for a few seconds. You can see a slight shift in your view every time you alternate between eyes. You’ll see the line slightly on the left when you will see it with your left eye. If there are only slight movements, you can consider it as normal. But if there are excessive movements in the line, you have to adjust the device.

3. Vertical Collimation

Rest your eyes again for a couple of minutes. Look out for a prominent horizontal line on the edifice. Take your eyes about 4 inches apart from the binoculars but keep your eyes on that horizontal line. Look out to find if there’s any disproportionate horizontal line on any of the lenses. The line should be unbroken if the binocular is in good condition.

4. Locating the Screws

You can locate the setscrews for the tilt adjustment of the prism on each barrel’s eyepiece. If your binocular is rubber-covered, you can use a 1mm screwdriver for prying open the cover gently and locate the setscrews. Now, adjust the setscrews using that same screwdriver.

5. Setting the Setscrew

Turn the setscrew in a clockwise motion on the left barrel. The image will move to the right and downward. Turn them counterclockwise, so the image turns to the left and upward. On the right barrel, spin the setscrew in a clockwise motion and the image will move to the left and downward. Spin the screw counterclockwise and the image will move to the right and downward.

If your image is still out of alignment, repeat the direction. The image should horizontally merge without vertical displacement. Your binocular vision will be normal once you’re done with this method.

How to Repair the Lenses?

The most important and delicate part of binoculars is the lenses. They also cost the most. The lenses get damaged mostly when binocular harness is not used and binoculars fall out of hand or get hit by a sandstorm. Problems in the lenses also cause focus problems in them. Follow these steps for this part of binocular repair:

  • Get a screwdriver for opening tiny screws around the lens. You can get them at any optic repair shop
  • Other things you’ll need: binocular manual, wiping cloth, kitchen tissue, a scale, and soap solution
  • Locate the lens screws. In most of the cases, they’re at the top right corner of both of the lenses
  • Remove the screws and then both of the lenses
  • Clean the lenses and dry them out. Mark the central position on both of the lens cups
  • Place the lenses at the center point after they’re dry
  • Put the lenses back and adjust positions with tweezers
  • Check if the lenses are in the exact place
  • Tighten the screws
  • Take the measuring scale and calculate the center of both sides. The repair is a success if the centers are equally distant from both of the sides
  • Even if there’s a slight issue on the positioning, you can now easily follow these steps again

How to Repair the Focusing Knob?

When you use the focus knob too much, it creates friction and the knob becomes unusable. High-quality binoculars come with good knob material and rugged construction. So its better to do some research before buying the right binocular. But this knob issue is very common and you can easily repair this at home. Things you’ll need for this binocular repair are:

  • Odorless and colorless grease
  • Cotton buds
  • Magnifying glass (optional)

Here’s how you can start on the repairing process:

  • Open the focus knob using the large screw on the top of the knob
  • When you’ve successfully opened the knob, take a cotton bud and clean the knob from the inside. You may also use a blowing brush
  • Grease the cotton bud and gently apply on the knob
  • Tighten the screws again
  • You may have to tighten the screws more than once since they’ll get slippery from the grease

How to Use a Binocular Properly?

We’ve talked about repairs on a binocular but with proper usage, you can prevent any of these issues from happening. Here are some precautionary measures of using a binocular:

  • Never use any damp space for storing binoculars because this encourages fungus growth
  • Don’t bring out your binoculars when there is strong wind or heavy rainfall
  • Don’t change lens settings too often
  • Don’t put too much pressure on the lenses or you’ll lose the center. Thus, you’ll have to relocate the lenses for a proper focus
  • Never look towards the sun using your binos
  • Use a binocular case all the time
  • Clean your binoculars frequently to prevent any fungal growth on the lenses

Now you don’t have to rush down to the local optic repair shop every time you see doubles on your binocular. The repairs we’ve discussed cover most of the issues with binoculars. But if you’re missing a part or there are cracks and broken parts on your binoculars, you can’t perform the binocular repair DIY methods we’ve discussed. You’d have to go to a repair shop or contact the manufacturing company for the missing or the broken parts. If you use your binocular the way we’ve pointed out, you can easily fix them at home with these binocular repair methods.


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