Archived posting to the Leica Users Group, 1997/11/17

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: Re: Advice on 21 S/A
From: dannyg1@IDT.NET
Date: Mon, 17 Nov 1997 17:04:17 +0000

Paul,

> This is also the reason that some companies had 55mm, 58mm, etc.
> normal lenses in the 1950s and 1960s; they made them just long enough so
> that they did not have to be retrofocus.

I believe you're mistaken in this notion quoted above. Though I haven't checked the 
entire roster, flange to focal plane distance on most SLR's are shorter than 46mm. The 
reason most often used in advertising for 55 and 58mm lenses was that they matched 
unaided view magnification and allowed use of the camera with both eyes open. 
Standard view magnifications were in the 0.88x range if I remember correctly; they're 
now much smaller (around 0.75x average).

Regards
Danny Gonzalez