Leica M9 Frameline sizes vs. Lens Coverage

[Rob-F]

I wanted to see how well the M9 framelines represented the coverage of my lenses. I knew from previous observations that my several 50mm lenses have slightly different coverage owing to small focal length differences.

This experiment is for the 35, 50, 75, and 90mm focal lengths. I set up a tape measure on the mantle and put the M9 on a heavy tripod at a convenient distance. I focused the camera, wrote down the width on the tape measure between the left and right framelines, and clicked the shutter.

For the 35mm Summicron ASPH, the width as seen in the finder was 42 inches. Here is what the sensor saw, about 42.5":

For the 50mm Summicron 11819, I saw 27 inches in the finder, and the camera recorded 28":

The 75mm frameline measured 19 inches in the finder, 18 inches on the sensor with the 75mm Summicron ASPH:

And the 90mm frameline was 15 inches in the finder, with 15 inches registered in the image for the 90mm Summicron ASPH:

These tests were done near minimum focal length. There would be some differences at longer ones, but a test at longer focal lengths might be more of a challenge, because it would be hard to read the tape through the viewfinder at 50 feet!

The next time I feel like a project, I might try a comparison of my several 35mm lenses, my 50mm lenses, and 90mm lenses. I don't have more than one 28mm but I could test several of these three classic focal lengths.

Thanks for looking.

 

[pyeh]

Good stuff, Rob-F. Thanks.
I think the M9 is set up with framelines to be accurate at 0.9m or maybe 1.5m. I can't remember exactly.

 

[kshapero]

We always knew these numbers were something like this. Part of the charm of rangefinders, I say.

 

[Ko.Fe.]

Somewhere on the net I have seen illustration of M9 35 mm frameline significant inaccuracy with true 35mm lens. It was showing more accurate framing at 35 with 40.
I went all Rokkor exercise only to find out I don't like its FOV. Too narrow.

As for M9 50/75 framelines... They are so cluttered, most of the time I don't even pay attention which of two I use. 🙂

 

[Rob-F]

Somewhere on the net I have seen illustration of M9 35 mm frameline significant inaccuracy with true 35mm lens. It was showing more accurate framing at 35 with 40.
I went all Rokkor exercise only to find out I don't like its FOV. Too narrow.

As for M9 50/75 framelines... They are so cluttered, most of the time I don't even pay attention which of two I use. 🙂

I agree with all of that. Yes the 40mm frameline is closer to the truth with most current Leicas. But who wants a 40mm FOV? And the 50/75 pairing? Yes, very cluttered.