Let’s say you did all the proper research, went out and bought your first pair of premium hunting binoculars, but once in the field you just could not get them into focus. You’d be pretty upset right? That might sound farfetched to some, but it’s more common that you would think. These tips will show you how to focus your binoculars the right way.
Individual Eyepiece Focus
First, point your binoculars at something in the distance. Choose something that is in the general range of where you will be scanning.
Next, cover the right lens tube, or close you right eye and adjust the focus on the left eyepiece until your target is in perfect focus. Then cover the left tube or close your left eye, and adjust the focus wheel on the right eye piece.
It is a really simple process, but most people don’t realize you need to close one eye and focus the other in order to have the best vision. It’s sort of like going to the eye doctor to get a new glasses prescription.
Center Focus Method
Some binoculars, usually the cheap ones, have only a center focusing dial, with no individual eye adjustments. In this situation, you should focus the eyepieces to your dominant eye. For most people their right eye is dominant, and you’ll want to cover the left lens up when focusing on an object.
If you still are getting a fuzzy image, then you may have some differences in vision between your eyes. At this point you should consider buying a higher end pair of binoculars. You’ll experience less eye fatigue and be able to scan for much longer periods of time.
Focusing Binoculars with a Diopter
Most modern binoculars for hunting have a diopter adjustment. A diopter is a control on one of the eyepieces, usually on the right side of your binoculars. By setting the diopter properly, you can compensate for differences in vision between your eyes.
First, make sure the diopter is set to 0, or set it to point at the symbol if there is one. From here you can turn the diopter left or right on the focus scale, but don’t do that just yet.
Now, cover the lens barrel of the side that has the diopter. Don’t just close your eye or squint; you want to have both eyes relaxed and open to get the best results. Next, point your binoculars at a target down range and use the center focus dial until you get a sharp and crisp picture.
While maintaining the center focus wheel position, cover the left barrel with the lens cap. Now point your binoculars at the same object in the distance. Do NOT adjust the center focus dial, and then start adjusting the diopter wheel on the right eye until it is crystal clear focus.
If your diopter has a locking mechanism, now is the time to lock it down. This prevents accidental movement and unnecessary refocusing.
Note: If you are changing your target range frequently, you’ll want to refocus each time to get the best picture. Once you have these techniques down, it’s a quick adjustment.
Still out of Focus? Check the Collimation
If your binoculars are out of collimation, you will experience eye fatigue just like you will from poor focus. Collimation is a fancy word for the lenses and prisms all being optically aligned on the same axis.
When one or both binocular tubes are out, they won’t match up with each other and you’ll get a slight double vision effect. You can check this by collapsing the bridge of the binoculars until you see one large circle of view.
Look at an object that has a straight edge to it like a power line or a ledge. Slowly pull apart the binoculars and watch the straight edge.
If your picture remains the same, and the edge is continuous, your alignment is good. If the edge separates into two, then one of your tubes is out of collimation.
You can try this method to realign them yourself, or you’ll need to return them to the manufacturer for repair. If all else fails, you’ll just have to get a new pair.
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