Archived posting to the Leica Users Group, 2003/03/11
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Lea-- The rangefinder will show a double image even when there's no lens on the camera. It will even "focus" when the lens is capped. I just took my M7 and 50 f/1.4 out and pointed towards the window with the cap on, and I can still focus the camera. The two rectangles align themselves just fine. When I remove the cap, I'm still in focus. The rangefinder is a mechanical device. When you have no lens on the camera, the double image of the rectangle shows up in a default position. When you place a lens on the camera, the lens and camera are linked mechanically, so that when you turn the focusing ring on the lens, the rangefinder shows you what will be in focus at the distance determined on the lens itself. The lens isn't actually "seeing" the subject in the same way that an SLR lens would "see" it, that is, to transmit the image via the mirror and through a prism to the viewfinder. It is a mechanical device that measures distance between the film plane and the subject accurately, and provides the rectangular patches for your convenience, so that you can "see" what's in focus. It's a symbol for what is happening between lens and rangefinder. The light that illuminates the rangefinder patch and bright-line frames comes from the little window that looks as if it has a set of vertically aligned venetian blinds on it ... that provides the light for the viewfinder window. You can also focus the lens without ever looking through it, by using only the lens markings themselves. That's how professional cinematographers do it ... the focus-puller doesn't look through the viewfinder, she sits next to the camera and focuses by judging distance and adjusting the lens based on the distance markings on the lens. The same principle applies to the rangefinder. Kit - -----Original Message----- From: owner-leica-users@mejac.palo-alto.ca.us [mailto:owner-leica-users@mejac.palo-alto.ca.us]On Behalf Of lea Sent: Tuesday, March 11, 2003 12:07 PM To: leica-users@mejac.palo-alto.ca.us Subject: [Leica] focusing question deux Here's what comes of carrying my camera around playing with it.... Why, when my lens cap is on my lens can I still see a double image? Where is it coming from and why does focusing the lens (even tho it's capped) allow me to focus? I'm sure this is some wonder of rangefinders that I'm not familiar with but it seems to me that the capped lens ought to be preventing the double image. I guess I've always thought that the 'main' (read: non-moving) image in the viewfinder was from the viewfinder and the second 'ghosted' image was coming from the lens. This is clearly not the case. What's up? Lea Murphy Whiny Dog Press www.whinydogpress.com New images www.whinydogpress.com/new.html Picture a Week PAW http://www.whinydogpress.com/paw.html - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html