bright line finders and parallax error

I just got a bright line finder to use with my 28 lens (for my M4

and M6). I find it helps tremendously in seeing the entire

frameline. My question is regarding parallax error. At what

distance should I really be concerned about parallax error when

using the external finder for framing (especially since the

placement of the finder isn't directly over the lens, but a little to

the right of the lens). A side question is why the hot shoe isn't

positioned such that it's directly over the lens in the first place.

Thanks.

About 10 feet, as I recall; note that the frameline doesn't quite

cover the whole image anyhow. On the Leica I and Standard the

accessory shoe was located directly above the lens, so apparently it

was moved because it would somehow intefere with the rangefinder

innards of the model II.

FYI... I posted a site for a new Leica finder on this forum, (see

this thread, "M using wide angle fans... a new finder"), and the new

finder is indeed centered over the lens via an off-set foot. I know

this doesn't help your particular problem, but they are making an

attempt to reduce the parallax error.

<p>

One thing I did was to mount my camera on a tripod several feet from

a wall, view through my finder and have my partner place 4 small

pieces of tape on the wall at the corners of my frame lines as per my

verbal instructions. I did this at various distances, shooting some

slide film. Viewing the unmounted slides, the farther from the wall

that I got, the more space was showing around the tape, (which in

theory should have been at the extreme corners). Try this

experiment, and you might be surprised. As a minimum, you will have

an idea on when to start mentally compensating. This test also made

me appreciate my 100%viewfinder SLR for important compositions.

A very easy way to check your viewfinder is to take the back off your

camera, put the baseplate back on, and use a locking cable release to

keep the shutter open on B. Then you can alternately look through the

finder and through the camera back to see how the two views compare.

I use easily spotted targets--for instance the vertical sides of

picture frames on my wall for the left and right edges of the finder.

Just look through the back and swing the camera until the edge of the

picture frame is on the edge of the film opening, and then look

through the finder to find out what it's thinking. Same idea for the

top and bottom, and at various distances. This is quicker than film.

Michael´s trick is a fast answer to your dudes, I just don´t know why

you find it depressing Bill, may it be ´cos you have to keep the

shutter "depressed" in B?

It's because all that extraneous image which will be on the negative,

outside that indicated by the framelines (CL, M4P, and M6).

Ummm, you will of course need a focusing screen to be able to

"see" the image at the film gate....

<p>

Cheers,

No, you don't really need a focusing screen. Just use a loupe or

another Leica lens backwards to focus on an image at the edge of the

film plane. I haven't studied optics for over 50 years, and I can't

recall if this is a "real" image or whateverthehell the other kind of

image is called.

So the problem seems to be the full format view on prints?, I have

done that of seeing with a loupe, and thougth of that as a real

image, but the problem seems for me in determinating where is the

plane you are seeing through the loupe, is funy I have work with my

Leicas M for years, and never have a dude of what I was seeing, now

I´m allways chequing.

Virtual image? Or is it called an Aerial image? I seem to recall

that an image formed just out there, in the air, is called an "aerial

image." Maybe these two terms are interchangeable, though.