2 0 ▁( Standard , ▁Autom at , ▁Let ter ▁Mod els , ▁Rol lei - Mag ic , ▁and ▁T ▁model ), ▁and ▁ 1 2 7 ▁( B aby ▁Rolle if lex ). ▁ ▁The ▁Rolle if lex ▁T LR ▁film ▁cam eras ▁were ▁notable ▁for ▁their ▁exception al ▁build ▁quality , ▁compact ▁size , ▁mod est ▁weight , ▁superior ▁opt ics , ▁dur ability , ▁simplicity , ▁reliable ▁mechan ics ▁and ▁bright ▁view find ers . ▁They ▁were ▁popular ▁and ▁widely ▁im itated . ▁ ▁The ▁high - quality ▁ 7 . 5   cm ▁foc al ▁length ▁l enses , ▁manufact ured ▁by ▁Ze iss ▁and ▁Schne ider , ▁allowed ▁for ▁a ▁smaller , ▁l ighter , ▁more ▁compact ▁camera ▁than ▁their ▁im it ators . ▁The ▁highly ▁regarded ▁Ze iss ▁Plan ar ▁f 2 . 8 ▁and ▁Schne ider ▁X en ot ar ▁l enses , ▁both ▁ 8 0 mm ▁foc al ▁length ▁and ▁fast ▁in ▁comparison , ▁are ▁both ▁state ▁of ▁the ▁art ▁opt ics . ▁Un ique ▁to ▁the ▁Rolle if lex ▁Autom at ▁and ▁letter ▁model ▁cam eras , ▁the ▁mechanical ▁wind ▁mechanism ▁was ▁robust ▁and ▁clever , ▁making ▁film ▁loading ▁semi - autom atic ▁and ▁quick . ▁ ▁This ▁mechanism ▁started ▁the ▁expos ure ▁counter ▁automatically , ▁auto - sp ac ed ▁the ▁ 1 2 ▁or ▁( on ▁the ▁later ▁model ▁F ▁cam eras ) ▁ 2 4 ▁expos ures , ▁and ▁t ension ed ▁the ▁sh utter ; ▁all ▁with ▁less