Passively Athermalized FF Lens


A military flight application requiring a fixed focus lens with no moving parts.


The desired lens must focus from a relatively-close 3 feet to infinity with no mechanical focus adjustment, while having a wide (+160°) field of view and athermal over a temperature range from 50°F to 122°F.


Durability:The lens had a very durable and ruggedized design.
Innovation::No motors, power, or moving parts are used with the lens; the system is completely passive.
Design:All materials used in the design have a normal coefficient of thermal expansion (CTE), but the design was able to accommodate in temperature shifts (both optically and mechanically). The lens stays in focus over the entire thermal range.
Compact:The finished lens measured only 2.5” Dia. X 2.2” Length.
Lightweight:The finished lens only weighed 12 ounces.
Production:irZoom now offers this lens as a standard, off-the-shelf solution (used with a Tau 640 camera).