I'm running the Viewshed tool using Lidar with 1m post spacing. I have a an observer point and target point attributed with an OFFSETA and OFFSETB at 5m. I need to run the Viewshed multiple time for targets at multiple distances from a static observer point. As i increase the RADIUS2 at increments of 50 meters out to 350 meteres I notice slight changes in pixels becoming Visible and Not Visible in the inner regions that I would think would not change. Why would these values change if I'm accepting all other defaults? I don't think that the small number of changes will impact my analysis, but I'm just curious to why this would happen.