Isipili esijonga ngasemva ayisosipili esisicaba, kodwa sisipili esiyiconvex.Indawo yokujonga isipili esingasemva ixhomekeke kwizinto ezintathu: umgama phakathi kwamehlo omqhubi kunye nesipili esingasemva, ubungakanani besipili esingasemva, kunye neradiyasi egobileyo yesipili esijonga ngasemva.Imiba emibini yokuqala ngokusisiseko ilungisiwe okanye ayilawuleki, kwaye eyona mpembelelo ichaphazelayo isiphumo kukugoba kwesibuko esingasemva.Incinci i-curvature radius yobuso besibuko, inkulu ibala lokujonga elibonakalisiweyo, kodwa kwangaxeshanye, iqondo elikhulu lokuguqulwa kwento ebonakalisiweyo, kwaye ikude ukusuka kumgama wokwenyani, onokubangela lula inkohliso yomqhubi.Ngoko ke, i-radius ye-curvature ye-mirror surface inoluhlu olulinganiselwe oluchazwe yimigangatho yoshishino.Ikwachaza ukuba indawo yofakelo lwesipili sangaphandle esijonga ngasemva mayingagqithi kumda we-250mm wemoto.