Lens focal lengths

Focal length is the other half of every range figure on this site. A longer lens narrows the view and stretches every Johnson range in proportion; it also gets heavier and dearer fast, because thermal lenses are germanium. Grouping by lens shows how much of a unit's reach is the glass rather than the core.

• 7 mm lens2 units · est. detection 146 m–146 m
• 9.1 mm lens2 units · est. detection 190 m–190 m
• 10 mm lens6 units · est. detection 208 m–208 m
• 15 mm lens7 units · est. detection 313 m–313 m
• 19 mm lens28 units · est. detection 279 m–396 m
• 24 mm lens2 units · est. detection 500 m–500 m
• 25 mm lens56 units · est. detection 368 m–521 m
• 30 mm lens3 units · est. detection 441 m–625 m
• 35 mm lens124 units · est. detection 515 m–729 m
• 40 mm lens2 units · est. detection 833 m–833 m
• 42 mm lens7 units · est. detection 618 m–875 m
• 50 mm lens85 units · est. detection 735 m–1,250 m
• 60 mm lens13 units · est. detection 882 m–1,250 m
• 75 mm lens10 units · est. detection 1,563 m–1,563 m
• 100 mm lens2 units · est. detection 2,083 m–2,083 m

Only groups with two or more units get a page — one unit is not a comparison.