which 28mm viewfinder for Leica M

[puketronic]

There seems to be quite a few from Zeiss, Leica, and CV.

How do they compare in terms of brightness, flare, distortion, and magnification? My feeling is that zeiss is the best in all regards, followed by leica, and then cv. Many people seem to state which viewfinder they prefer without going into the specifics in why.

More specifically,

1. I hear that the Leica's lock, is this true only for the plastic ones or do the older metal ones lock to? Locking would be handy but I'm not sure if it is a deal breaker or not.
2. Anyone feel the non-Leica ones are less accurate? The Leica ones I believe take into account the offset from the shoe to the lens. I'm hesitant to go non-leica for this reason. However, many prefer the Zeiss and this does not seem to bother them. I worry because I shoot at close distances (1-3 meters) often but prefer to not go with SLR's. I'm not that precise with my composition/framing.
3. Do they all have framelines, which allows me to see the most outside the frame. I really like framelines.

 

[John Koehrer]

None of the older Leica VF's lock, never used a new style.

Since most finders are designed for use at infinity I doubt there's any vertical compensation for composition. If you're not that precise with composition anyway, I doubt you are going to see any difference in any of them.

The older Leica type use a frame(sort of) internally but it's in the rear, at the eyepiece and it does have a correction line to deal with parallax at near distances. The framelines being at the eyepiece however don't allow you to see outside the lines. You're viewing directly through the front element.

I owned a CV finder at one time. Two things I remember, No lock, and it had been dropped and the frame was knocked out of horizontal alignment.
It was an obvious defect but an easy fix.(plastic crap). )