Using SmartPin On My Scope

This is a photo of my scope (Schmidt&Bender 12.5-50×56 FT) with my new SmartPin adjustable pointer. As we all know, S&B scopes shift a lot in rangefinding as the outside temperature changes. (Click here to read more about parallax shift.) On my scope, every 10 degrees in temperature mean 4.5 yards shift on a longer (45-55 yds) target. This means a bit more than 8 mm shift on the standard 5″ (125 mm) S&B sidewheel.

I printed the sidewheel scale for 10°C so I can use my scope in a temperature range of -2.5…22.5°C. Of course I could have used another base temperature, summer and winter settings e.g. 20°C for 7.5…32.5°C or 0°C for -12.5…12.5°C, etc. But here in England, this scale on the picture will do all year :-)

Since the base temperature of my scale is 10°C, the middle position of the pointer will be used when it’s 10°C on the course. It it’s 15°C, I find this temperature on the small table (1), adjust the pointer to this position (2) and read the appropriate click and/or range value from the wheel (3). During a competition, I can periodically check the temperature of the scope (using aquarium temp strips) and can set the pin to the right position, so I don’t need to calculate compensations and shifts when shooting.

This is the precise and scientific method. If the temperature doesn’t change too much all the day, you can simply measure a 55 yards target on the zero range and then adjust the SmartPin pointer to the 55 yds mark on the sidewheel. Anyhow, your scope will rangefind the real distances, if you use this adjustable pointer properly.

The SmartPin adjustable pointer on the photos above has got only one pin, but I deliver it with two pins (as seen on the product page), so those shooters who are sensitive to light conditions. Usually, it’s not the scope’s fault, if you rangefind different ranges in different light conditions, it has much more to do with your eyes. The human eye accommodates much faster if the picture is highly detailed and light enough. As you rotate the sidewheel, your brain tries to correct the unsharp image so you will see it sharp a bit before it is really sharp. This difference depends on the light conditions, your age, your fitness at the moment etc. So you can use the twin pointers for light and dark targets, or for fresh and tired eyes, as you wish.