Why M vf not like SLR

This could well be a really naiive if not downright ignorant question

but please indulge me. How is it that the 35mm or 28mm view through the

M viewfinder not like that of any SLR? There are no distortions even

though it covers the same field of view as when a 28mm lens is attach

to an SLR. Foreground/background perspective contrast is also not

extreme. Am i not looking at the same angle/field of view in both

system? Thanks in advance. Cheers.

If I'm understanding what you're saying, the reason is that the viewfinder on a rangefinder isn't looking through the taking lens. Meaning you're simply just seeing an image of the scene basically. Focus isn't shown (except in the focus aid) and neither is the DOF. If you use an SLR, you can see what the DOF will look like and the other properties of the lens will be obvious in the viewfinder. Is this what you're asking?

If I'm understanding what you're saying, the reason is that the viewfinder on a rangefinder isn't looking through the taking lens. Meaning you're simply just seeing an image of the scene basically. Focus isn't shown (except in the focus aid) and neither is the DOF. If you use an SLR, you can see what the DOF will look like and the other properties of the lens will be obvious in the viewfinder. Is this what you're asking?

oops, sorry

Thanks Carl. Well what i want to ask is that even though the vf is not through the lens it has the same field of view as, say a 28mm lens, how come it doesn't look like a 28mm as seen through an SLR viewfinder? Any clearer? I'm so sorry for the confusion.

I <i>think</i> it's because the slr viewfinder compresses the, say 84° or whatever of a 24mm lens into the normalish however many of a 50-ish field of view, whereas the rangefinder viewfinder simply draws a line around the full 84° field of view and your eye has to move over that entire range. This makes sense to me, but I may not have succeeded in expressing it clearly.

Perspective distortion <i>in the viewfinder</i> depends on the magnification factor of the viewfinder or viewfinder/lens combination (SLR). At 1x, it's natural. At < 1 you get wide-angle distortion. At > 1 you get a compression effect.

 

The magnification factor of the standard M6 is .72x, mild wide-angle distortion, no matter what lens is mounted. If memory serves, most SLR's I've used seem to be at 1x at somewhere around 70 mm, which would mean they're at maybe .4x with a 28mm lens mounted. This varies somewhat with the camera.

 

Another way of looking at it is that the view through the eyepiece is wider with an M camera. An SLR is compressing the wide view into a narrower view more than the M.

Here's my try. What you see over the whole VF field in an M is the same (as long as the VF size remains the same, i.e. a 0.58 or 0.72 or 0.85) because that VF's window you're looking through does not look through the lens, like an SLR does. (The M6 TTL is called TTL because its <i>light meter</i> capability <i>does</i> look through the lens.) So, if you're using an M 28 or a M 135 lens, the whole field you see remains the same. "All you're going to get covered" in your shot is "only" that seen within the appropriate frame lines visible within the VF. Since a 28's angle is much larger than that of a 135, the 28's frames are the biggest, and the 135's the smallest. Got it?

Or, in other words: it's just in your mind. Different ways of looking at the same scene make our visual cortex boggle. For a few thousand years (or a few million, taking the evolution of mammals into account), no eye ever had to deal with additional optics, so we just don't manage to adapt to them easily. Nothing to worry about!

I think Rob & Mark got it--if the Leica M's VF had a zoom or turret feature that changed the magnification w/each focal length, like some of the old Zeiss, Tewe, Nikon, etc. accessory finders (or the Contax G2), then you would get a more SLR-like view. Michael, I believe the M6 "TTL" designation refers to that model's TTL flash capability (both the M5 & the M6 "Classic" had TTL metering).

This is why I almost always use the accesory 28mm finder. It does look more like what you see through the actual 28mm lens on an SLR.

Christopher, maybe you're right, maybe we're both right! I was only thinking of light-metering. (a) I don't have an M5 or M6 classic, but a TTL, and I haven't been interested (yet) in flashes. (b) Here's what they say as re the TTL's technical data:

 

"... selective through-the-lens exposure metering of the ambient light, or centre-weighted integral metering of the flash light with compatible flash units."

There's nothing about it that's "in your mind" (except that all vision processed in your brain, obviously). Perspective distortion is a matter of basic geometry, not psychology.

The Leica VF and an SLR viewing system are totally and completely different in how they work.

 

The Leica VF is a window that you look through. In the simplest case, it would just be a plain window. What's actually there is a simple optical system that shrinks the view a bit so you get a wider than normal field of view. It's actually like a small telescope only in reverse. The viewfinder depends on your eye to create a focussed image to look at, so to your eye the entire viewfinder image looks equally sharp, just like you were looking through a window.

 

When you look through an SLR, you are looking at a projected image through the lens attached to the camera itself. The image goes off a mirror and through a system of prisms and is projected onto a screen. Since the image is created by the lens, only a single plane of the image is in focus at any time, and you perceive limited depth of field.

 

A nice discussion of how Leica style viewfinders work can be found on this web page:

 

http://rick_oleson.tripod.com/looking_forward.htm

I think the main difference between the Leica M VF viewing and SLR viewing is relatively simple. I'm surprised noone has mentioned it so far. When you look through the M VF, even if you close the other eye, you are still essentially viewing a three-dimensional world, because even with just one eye open (an even demagnified to 0.72X or whatever), the brain can properly interpret the scene as having depth. When you look through an SLR VF, you are looking at a scene projected onto a flat screen by the lens, so you are viewing a 3D scene in only two dimensions. The SLR viewing is more akin to what the film "sees" than the Leica M viewing, so you have to use greater imagination in visualizing how the scene you are viewing will appear on film.

 

Of course the SLR can show you depth of field ( stopped down), flare, etc., while the M VF hopefully does not show flare. :-)

Steven: The previous answers have been essentially right, but sort of skirting around the edge of the issue.

 

Take a print of a picture shot with a 28mm.

 

Hold it up in front of you so that the print outlines are about the size of an SLR viewscreen as seen through the finder. For a 6x9 inch print this will be approximately 18" from your eyes. You may need to hold up your/an SLR to the other eye to get the 'boxes' to match.

 

Take the lens off the SLR, because I'm not talking about the scene within the finder, I'm talking about the size of the rectangular framing device itself.

 

That's how the SLR viewfinder shows you the scene.

 

Now move the print closer to your eyes until (how to say this clearly?) the print is as big as the 28 framelines in a Leica - my experiments put this at about 10 inches.

 

That's how the Leica viewfinder shows you the scene - same cropping (roughly!), same perspective - but as a bigger chunk of space in front of your face. And now the scene SEEMS less 'distorted' in the print as well, because the viewing angle for the print when it's close is closer to the 'real' 70-degree angle the 28 lens actually saw.

 

You can do the same thing with a print from a 135 or 90 lens, by the way, just to show the effect is consistent across all focal lengths (but in the opposite sense for lenses above about 75mm).

 

Again, the print will be about 18 inches away to match the outlines of the SLR viewfinder, but it needs to be at least 36-40 inches away to fit into the 135 framelines through the Leica viewfinder (.72x), and about 24 inches to match the 90 framelines.

 

In effect, the SLR viewfinder shows you a constant 'print size' and varies the magnification within that 'print' as you change lenses, while the rangefinder shows you a constant magnification and varies the 'cropping' within that magnification as you change lenses.

 

As extra-credit homework - make 3 prints from the same 28mm negative, full-frame: one 2x3 inches, one 4x6 inches and one 6x9 inches. Look at them all side by side from the same distance. The 2x3 print will give a much stronger impression of "wide-angleness" than the larger prints - just as the SLR finder does - because it has 'compressed' the 28's wide view into a fairly narrow area.

 

This is why the accessory 28 finder that Jay uses works so well for showing the "wide-angle" effect. It strongly reduces the magnification of the scene, so it's like looking at the 2x3 print compared to the 6x9 print.

BTW, Eliot posted his excellent observation while I was posting my tome.

 

This is why Lee Friedlander (or Gary Winogrand or whoever) said "I photograph things to see what they look like photographed."

 

Only a rangefinder shooter would say that. An SLR user would KNOW what the scene was going to look like photographed - from the 2D image on the ground-glass.