rf baselength question

[shaaktiman]

Hey all,

I'm new to rangefinders, having just bought a bessa-r2 a few months ago and I have a question about something I keep reading about on the site. What's the story with RF baselength? I DO realize that it's difficult to focus my 90mm lens when the subject is close with the r2. Why is that?

thanks,

shak

 

[pvdhaar]

The baselength is the distance between the viewfinder window and the rangefinder window. The longer the baselength, the more precise the rangefinder can be focussed.

Long lenses (90mm and over is long in terms of rangefinder cameras) need to be focussed quite precisely close up when the selected aperture is large. So any bit of extra baselength helps in getting this precision.

But don't get too worried over baselength specifications!

It's only one of a number of factors that contribute to ease of focussing. Viewfinder magnification, viewfinder brightness, susceptibility to flare, they all affect how good and fast you can focus.

 

[Doug]

Hi Shak -- Welcome! You could hit the Search button and look for "baseline" or "baselength" and see what comes up, or refer to this thread: http://www.rangefinderforum.com/forums/showthread.php?s=&threadid=497&highlight=triangulation

 

[rover]

Here is a link to another explaination.

http://www.cameraquest.com/leica.htm

 

[Sumo_du_Jour]

Picture of different base lines. The vewfinders are lined up square for this shot. The cheap little Digi lens goes wide on close up, this distorted the image.

You can also see how the flash bounced off the Leica viewfinder glass, but not the Bessa's. The old glass on the Leica has some haze on the inside surface. Doesn't interfere with the view.

As mentioned previously, magnification is another part of the equation. There's a great image showing different viewfinder magnifications on the main Leica web site. It's worth hunting for.