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Bear 15x70 Binocular Minor Collimation Procedures

The typical (and usually very simple) collimation procedure for the 15x70 BEAR binoculars is often as an easy operation. One notable exception to this is when the binoculars are in gross misalignment. Gross misalignment is easily determined when the large circle of light beamed through the eyepiece end, as viewed _from_ the objective end, is noted as significantly off center of the binoculars internals. In other words, this large disc of light (which is the same exact thing as the aperture opening of the eyepiece itself) will not be seen as circularly centered against the circles that are the prism hole in the middle of the binos, and the objective lens circumference. These three areas mentioned are viewed in series from the front (objective) end of the binoculars. Choose the optical tube that looks the most misaligned when ready to make the needed collimation adjustment.

If the binoculars were already misaligned, or had become that way from a drop, etc., most often only a slight tweaking of one or both of the tiny set screws, that tilt the rear porro prisms (the ones nearest the eyepieces), is all that should be required. This procedure will true up the parallel nature of the two binocular tubes that make up the binocular vision.

To accomplish this truing of alignment, one should set the binos on a solid surface pointing them horizontally. Center in the field of view a focused image of a prominent, distant (about 1/2 mile or more away) fixed object. Tripod mounting the binoculars is also optionally good for stabilizing for this procedure and may be preferred to the solid surface mounting approach. The reason is you might can more readily position yourself behind the binos to work on them.

Take a very small 1mm size jeweler's flat bladed screwdriver and stick it into the gap at the edge of the rubber covering next to the prism covers (see image showing the location). These prism covers are the ones with the name and specifications on them and are located just under the eyepieces. The location to do the "prying" is right above the word "BEAR" on the left tube assembly, and also above the numbering "15x70" on the right tube assembly.

Work the screwdriver tip back and forth to s****e and pry loose the attachment of the rubber from the body itself. Separate the rubber just far enough back away from the body so you are able to grasp the edge of the rubber covering with thumb and forefinger. That will be enough so that the alignment screw can be easily accessed. Place a small acorn nut or similar object under the rubber covering to keep it well raised enough for accessing the adjustment screw. Place the screwdriver tip into the screw in the set screw hole. Next, place your eyes about 6" away from the eyepieces while looking at the chosen distant fixed object. View through both bino tubes together (at this 6" distance from the bino eyepieces) as you normally would do with regular viewing.

Turn the tiny screw back and forth slowly (less than 1/4 of a turn each way) while watching the images shift apart from one another or merge together. Find and stop turning it at the point where it seems to be best for a well joined (fused) image as viewed through both bino tubes. Note: Instead of being 6" away, you may have better results trying this procedure with the eyes right up to the binoculars as they would normally be used. See which works better for your eyes.

If the image still seems to remain a bit out of alignment no matter how close you can get the image to fuse, turn the tiny screw on the other tube in the same fashion to *walk* the images together better. The images will walk at a 90 degree angle to that of the first tubes adjustment screw motion. Once you get a feel for the motions involved with this, that should be all it takes to get good alignment with both optical tubes. The rubber covering most normally springs right back into place so there is not a need to glue it down. You can always go back and adjust things again if ever needed.

Good luck ... and may the images happily merge together for you!


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