Wollensak 8×10 Triple Convertible lens

Wollensak 8×10 triple convertible lens in Autex shutter, with focal lengths of 12″ (300mm) with both groups in place, convertible to 20″ (508mm) or 28″ (711mm) by using either group behind the shutter. The glass is good front and rear, with no pits, marks, fungus or any imperfections. The shutter does not work, but has indicated speeds of 1/100 to 1s. This lens is approximately f6.8 at wide open aperture and closes down to f64. The aperture lever moves easily, and the aperture blades are oil-free and work well. Note that the aperture scale is in the old system, and its widest aperture of below 4 is actually f6.8 as we know it; its smallest aperture at 256 is actually f64.

This lens was marketed as a versatile 8×10 lens choice for taking in the field, as it is a lightweight design and one could use it for three different focal lengths. Coverage seems more than ample for 8×10 with movements. It is a rapid rectilinear design, with two cemented groups of two elements each. Use this lens for wet-plate collodion or other slow processes where a fast shutter is unimportant.