View Full Version : zeiss protar V construction question

Victor Samou Wong
8-Jan-2006, 17:36
ok I'm not confused.... I've heard that the f18 protar is one doublet and two doublets.... how many doublets is it exactly? If I remove the rear, will the front element still work?


Jason Greenberg Motamedi
8-Jan-2006, 17:51
Looks to be 4/2 construction, that is two doublets. Work as a convertible? Maybe poorly (and VERY dimly) since the convertible "Double" Protars were 8 elements in 2 groups.


1909 Zeiss catalogue reproduction from www.cameraeccentric.com (http://www.cameraeccentric.com)

Ole Tjugen
9-Jan-2006, 00:30
From that diagram, it's not convertible. The different construction of front and rear groups indicate that the front group has most of the power, the rear is mostly correction. So front group alone would be short and poor, rear group alone would be long and even poorer - not to mention exceedingly dim.