This is the magnifying glass system, I do not know. I have experienced on a gun you spend 18-55 45cm to 10 cm focus. Exercise trickier on a canon 55-250, 55 assé still simple but proves beyond a tripod mandatory and yes a focus at 110cm past 15 cm and 20 cm 55mm to 109mm (not tried to 250mm ) it's not bad pitching. Good stuff.
