Archived posting to the Leica Users Group, 2003/07/30

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

Subject: Re: [Leica] arggghhh... rant at Keeble & Shucat...
From: Karen Nakamura <mail@gpsy.com>
Date: Wed, 30 Jul 2003 08:49:56 -0500
References: <BC92B520-C254-11D7-9647-003065BAFBD0@jphotog.com>

>A common mistaken notion. Focal length does determine focusing 
>accuracy with rangefinders. As the focal length increases, accuracy 
>drops. And at about 75 mm, the rangefinder becomes about as accurate 
>as focusing with an SLR. The wider the focal length, the more 
>accurate a rangefinder is compared to an SLR.


Well, from a strictly anal (this *is* the LUG) perspective, you're wrong.

The focusing error on an M7 @ 1 meter will always be +/- 1 cm (to 
just pull a number out of thin air).

For a 35mm f/2 lens, that's covered by DOF amply.

For a 50mm f/2 lens, that's covered by DOF.

For a 75mm f/1.4 lens, we're starting to get to the point where 
either bounds of the +/- 1cm will be visible.

So the focusing *accuracy* of a rangefinder is constant, it's just 
that that accuracy will be visible with certain lens combinations.

Karen Nakamura
- --
To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html

Replies: Reply from "Richard F. Man" <richard@imagecraft.com> (Re: [Leica] arggghhh... rant at Keeble & Shucat...)
Reply from Ted Grant <tedgrant@shaw.ca> (Re: [Leica] arggghhh... rant at Keeble & Shucat...)
In reply to: Message from Eric Welch <eric@jphotog.com> (Re: [Leica] arggghhh... rant at Keeble & Shucat...)