Sightron Model Differences
I got curious on what the differences between the SI, SII, SII Big Sky and SIII scopes and decided to email Sightron about them. I thought this would be good information to share.
"The SI is our low end model of scope. It has 4 layers of coating on the exterior lens and 1 layer on the internal lens. The SI is designed for low to medium recoil action. The light transmission is 86%.
The SII model has the Exactrack windage and elevation system, 7 layers of coating on the exterior lens and 4 layers on the internal lens. The light transmission is approximately 93%
The SII Big Sky is the upgraded models of the SII original line of scopes. It still has the Exactrack windage and elevation system, 7 layers of coating on the exterior and interior lens, more eye relief than the SII model, we redesigned the adjustable objective, added more minutes per revolution, has pull up resettable finger adjustable dial turrets on all the hunting models. Light transmission is approximately 95%.
The SIIISS LR model of scopes include a heavier Exactrack windage and elevation system, 30 mm tube diameter, the internal components are all heavy duty, thicker wall tubing, oversized target knobs that can be reset to zero. The SIIISS LR scopes have a side focus adjustable objective dial opposite the windage knob. 7 layers of coating on the exterior and interior lens. Light transmission is approximately 97%.
The SII, SII Big Sky and SIIISSLR Scopes can be used on any firearm."