frameline accuracy

[laptoprob]

Why are projected framelines so much wider than the projected frame at about 3m distance?
The difference is so much that the 40mm framelines in the CLE actually correspond with the projected image of a 50mm lens. Same for 28mm lines and 35mm image.
Same for 90mm.

It should be possible to make them a little more corresponding, right?

Rob.

 

[Kim Coxon]

The size of the framelines should vary as the focus moves. The is fairly easily done in simple cameras such as the Konica S2 and these do move in size as well as compensating for parallax. If you had a single set of framelines, you could make them adjustable but I doubt this would be easy or even possible with multiple selectable framelines.

Kim

 

[Ben Z]

Remember that the MP rangefinder is basically the same as the M2, designed in the 1950s. I find that, in comparison to mentally invisioning the amount of DOF for each lens at various apertures and subject distances, estimating the correct framing from experience is a walk in the park.

 

[Gabriel M.A.]

A bit of insight:

http://www.nemeng.com/leica/006ba.shtml

 

[Ronald M]

The problem is the angle of view changes as you focus closer. The frames are set for close up so you don`t get edges chopped off at close shooting. Down side is there is extra at distance. Starting with the M42 or MP, the problem gets worse because they shrunk the lines to accomodate the 28mm.

The most accurate viewing is with a bright line finder.

 

[laptoprob]

If I remember correctly Leica stated their framelines are made to be optimal at 3m distance.
The difference is - I think - about equally different in all brands, like CLE, Hexar and Bessa.
The frames are just very much tighter.
Separate brightline finders gave me the same difference.

Rob.

 

[Ben Z]

If I remember correctly Leica stated their framelines are made to be optimal at 3m distance.
The difference is - I think - about equally different in all brands, like CLE, Hexar and Bessa.
The frames are just very much tighter.
Separate brightline finders gave me the same difference.

Rob.

Leica's official statement is that the frame lines are set to cover the angle of view of each focal length at the minimum focusable distance of those lenses (ie .7m for 28-50, 1m for 75-90 and 1.5m for 135) minus an amount that would be masked by a typical slide mount.

The Leitz bright-line finders are framed tighter than the angle of view at infinity, but the old VIOOH/Imarect for the LTM are framed for infinity.

I too have heard that the M4-P and on have smaller frames due to the inclusion of the 28mm, and while I don't dispute the frames are tighter I don't follow the rationale. The 28mm frame appears only with the 90, so why would that have necessitated shrinking the other frames?

 

[Ronald M]

There is only one mask with all the lines and a mininum distance between them so what were are really talking about is 35/28 being vey close. Then they had to shrink the 50 cause the 35 go small and so on.

 

[Ben Z]

Except that it has been verified by numerous owners of early # M4-Ps that those have the larger 35 and 50 framelines of the M4-2 and earlier (I had one and compared it to my M4 and my MP when I first got it). And there is so much room between the 35 and 50 framelines that even if the 35 were "shrunk" it would not have been necessary to shrink the 50. There must be another explanation. Perhaps Leica felt the earlier frameline didn't leave enough wiggle room at close-focus not to cut off parts of a subject (though it's never happened with me). Leica has never offered up an official explanation TTBOMK.

 

[pvdhaar]

Basically it's a trade-off between the ability to compensate for parallax, or to compensate for field of view, and automatic frameline selection.

The auto-frameline selecting Hexar-RF and Leica M compensate for parallax, all four corners of the frame move from upper left to lower right when focussing closer.

The fixed focal length Hexar AF compensates for field of view and partially for parallax, only the upper and left frame lines move. The bottom and right stays fixed, as does the focus cross-hair.

To get best of both worlds, all frame lines should move but at a different rates. The upper left should move further than the bottom right when focussing further/closer. The rangefinder patch should move with a speed somewhere in between. It would be a nightmare construction if you also want to accomodate automatic frameline selection for different focal lengths.