▁pat ented ▁this ▁image ▁ere ct ing ▁system ▁in ▁ 1 8 5 4 . ▁This ▁system ▁was ▁later ▁ref ined ▁by ▁other ▁bin oc ular ▁mak ers , ▁not ably ▁the ▁Carl ▁Ze iss ▁company ▁in ▁the ▁ 1 8 9 0 s . ▁Bin oc ular s ▁of ▁this ▁type ▁use ▁a ▁pair ▁of ▁Por ro ▁pr isms ▁in ▁a ▁Z - sh aped ▁configuration ▁to ▁ere ct ▁the ▁image . ▁This ▁results ▁in ▁bin oc ular s ▁that ▁are ▁wide , ▁with ▁objective ▁l enses ▁that ▁are ▁well ▁separated ▁and ▁offset ▁from ▁the ▁e y ep ie ces , ▁giving ▁a ▁better ▁sens ation ▁of ▁depth . ▁Por ro ▁pr ism ▁designs ▁have ▁the ▁added ▁benefit ▁of ▁fol ding ▁the ▁optical ▁path ▁so ▁that ▁the ▁physical ▁length ▁of ▁the ▁bin oc ular s ▁is ▁less ▁than ▁the ▁foc al ▁length ▁of ▁the ▁objective . ▁Although ▁Por ro ▁pr ism ▁bin oc ular s ▁were ▁made ▁in ▁such ▁a ▁way ▁to ▁ere ct ▁image ▁in ▁a ▁small ▁space , ▁thus ▁using ▁pr ism ▁was ▁started ▁in ▁this ▁way . ▁ ▁Ro of - pr isms ▁bin oc ular s ▁ ▁Bin oc ular s ▁using ▁roof ▁pr isms ▁may ▁have ▁appeared ▁as ▁early ▁as ▁the ▁ 1 8 7 0 s ▁in ▁a ▁design ▁by ▁Ach ille ▁Victor ▁Em ile ▁Da ub resse . ▁In ▁ 1 8 9 7 ▁Mor itz ▁H ens old t ▁began ▁market ing ▁roof ▁pr ism ▁bin oc ular s . ▁ ▁Most ▁roof ▁pr