Well-known member
Jun 29, 2001
Reaction score
When these things first came out back in the 70's I got one right away. Since then, they have made dozens of models from the size of a pack of playing cards to the ones that were about a foot long. I have always carried a range finder although I now have a Bushnell 600 compact laser unit.

The split image units worked fairly well for ranges from 20 to about 250 yards as long as there was plenty of light. It was better than a guess at least. I still have one of the small ones but sold the big ones. You can pick them up for a few bucks if the $200+ laser models aren't in your budget.

Below are the operating instructions, for the big ones, in case someone has or wants one of these units and needs set up and operating instructions. These are from memory so they may not be exact. The smaller units operate similarly but the adjustments differ somewhat.

They work on a split image system similar to a SLR. Cameras. You may have to recalibrate the unit to fit your eyes.  A bright day is best for calibrating.

A.Adjust the monocular focus ring.
  1. Adjust the focus ring on the monocular to the desired setting.

B.Adjust the horizontal alignment.
  1.Select a distant object with a distinct horizontal line, like a power line.
  2.Hold the rangefinder level & look through it.
  3.If the object appears to be disjointed in the middle you will have
               to adjust it with the big adjusting screw on the front of the range
               finder. It should adjust easily, don’t force it past its stop.
  4.By turning the screw you will be able correct horizontal alignment
               until the object appears to be one continuous horizontal piece.

C.Setting the distance calibration.
  1.Select an object at a known distance (100 yards should do) with
               a distinct vertical line, like a fence post.
  2.Look through the rangefinder; you should see a double image
               of the object.  Roll the distance wheel until the double image
               becomes one distinct object.
  3.If your known distance matches the reading on the distance
               wheel, no adjustment is needed.  If it doesn’t, loosen the screw
               in the middle of the distance wheel, rotate the dial to the known
               distance and snug it down.

Top Bottom