Leica M2. why did they limit the eyepiece FOV?

[sanmich]

All M's have a metal part located just under the eyepiece, that limits the field of view somehow.

here it is from DAG site:
http://www.dagcamera.com/aper.htm

I have noticed that the opening on this piece on my M2 is considerably smaller than on my later M's (M4 etc) and this makes seeing the 35mm frame tricky (glass wearer). So I considered changing the mask for a modern type, but I also wondered what is the part function in the first place.

Flare reduction?
Physical protection of the glass?
Making sure the user eye is aligned to ensure RF function?

I wonder if it can be removed....

 

[KyleCharles]

I am wondering the same thing. Can it be removed or modified to make the hole even larger than the one on the M4?

Anyone?

 

[furcafe]

I actually asked your question, w/respect to the M2 anyway, many years ago. I did eventually get a somewhat satisfactory answer (I'll post a link if I can find it): IIRC, it was to indeed to reduce flare (light from the eyepiece side) & "force" the eye into the correct position (centering the RF patch), both of which were more of a problem w/the reduced magnification VF that was introduced in the M2.

It can definitely be removed & replaced w/the modern mask (which really isn't much smaller than an M3); enlarging the opening slightly (see the photo from DAG as to how little room there is to work with) would also be possible if you have the right tools (or technician to do it for you).

All M's have a metal part located just under the eyepiece, that limits the field of view somehow.

here it is from DAG site:
http://www.dagcamera.com/aper.htm

I have noticed that the opening on this piece on my M2 is considerably smaller than on my later M's (M4 etc) and this makes seeing the 35mm frame tricky (glass wearer). So I considered changing the mask for a modern type, but I also wondered what is the part function in the first place.

Flare reduction?
Physical protection of the glass?
Making sure the user eye is aligned to ensure RF function?

I wonder if it can be removed....

 

[sanmich]

later in the year, I found it....

http://www.rangefinderforum.com/forums/showthread.php?p=2155439

 

[mrmeadows]

some help for eyeglass wearers using RFs

some help for eyeglass wearers using RFs

People who shoot RFs while wearing glasses can do at least two things to improve their view through any viewfinder, and that constitute alternative to contact lenses. (People who are significantly far-sighted can't focus on the camera controls while wearing contact lenses, so contacts are not a viable solution, and declining accomodation ability with age makes the situation progressively worse.) The first of the two things is to choose eyeglass frames that place the outer surfaces of the lenses as close as possible to the eyes. Doing so will allow the viewfinder, pressed against the eyeglass lens, to be closer to the eye, thus gaining a wider angle of view through the viewfinder. This is especially important for far-sighted eyes, because the correction lens in the eyeglass frame will be a meniscus lens which protrudes out from the plane of the frame and pushes the viewfinder farther from the eye than the frame itself would. Picking an eyeglass frame with small lens size can reduce the protrusion and facilitate a closer approach to the viewfinder. The frame thickness should also be thin to keep the lens closer to the eye than a thick frame. The total difference will be only a few millimeters, but that makes a big difference in the view. The second thing is to have eyeglass lenses made of glass rather than plastic. The glass lenses are vastly more resistant to the inevitable scratches which plague plastic lenses, if one uses a rangefinder a lot. I've never found a scratch-resistant coating for plastic lenses that could withstand much contact with the viewfinder. To keep the heavier glass lenses from causing the eyeglasses to slip down my nose, I needed to put adapters which wrap around my ears on the ends of the eyeglass temples. Although I don't care too much about eyeglass style, I've now got the currently stylish narrow metal frames, and the adapters are hidden behind my ears and cause me no problem. These measures are not a complete panacea to the problem we eyeglass wearers face, but they have greatly improved my experience with all of my rangefinders, both analog and digital.