M8 finder magnification and frame line visibility

[sam_m]

I've been trying to get my head around the maths behind the M8 finder magnification, cropped framelines, and such like.

Taking the 24mm framlines for example, the m8 crop means these are equivalent to 32mm if they were on an m6, which means they should be easier to see than the 28mm frames on said m6.

In addition, the m8 sets these framelines to be accurate at 0.7m rather than 1m as on the m6, meaning they should be smaller still, than their film counterparts, right?

Finally, the finder magnification of the m8 is 0.68, which should mean even easier visibilty!

And yet, though I don't have an m6 or other film m to make a proper comparison, I'm sure the 24mm framelines in the m8 are only very marginally easier to see than 28's in an m6, much less than the maths would imply.

Have I got the maths right, and if so, what's going on?

 

[Bill Blackwell]

I've been trying to get my head around the maths behind the M8 finder magnification, cropped framelines, and such like.

Taking the 24mm framlines for example, the m8 crop means these are equivalent to 32mm if they were on an m6, which means they should be easier to see than the 28mm frames on said m6.

In addition, the m8 sets these framelines to be accurate at 0.7m rather than 1m as on the m6, meaning they should be smaller still, than their film counterparts, right?

Finally, the finder magnification of the m8 is 0.68, which should mean even easier visibilty!

And yet, though I don't have an m6 or other film m to make a proper comparison, I'm sure the 24mm framelines in the m8 are only very marginally easier to see than 28's in an m6, much less than the maths would imply.

Have I got the maths right, and if so, what's going on?

Make that a .68 mag "equivalent."

I haven't spent much time pondering this, but I have thought about it.

My thoughts are -

1) The 24mm framelines (32mm equivalent) are indeed more forgiving in the corners than a 28mm lens on an M6, as they should be;
2) The 32mm equivalent is close to 28 (closser than you think);
3) The .68 equivalent mag. on the M8 is very close to .72 on an M6; and
4) I would suggest emailing Leica with the question for their "scientific" response. Then report back with what they say.

 

[sepiareverb]

Tighter than I'm used to is my answer. I've got one on 'Test Drive' and getting more than I expect to compared to the M7/MP.

 

[sam_m]

2) The 32mm equivalent is close to 28 (closser than you think);
3) The .68 equivalent mag. on the M8 is very close to .72 on an M6; and
4) I would suggest emailing Leica with the question for their "scientific" response. Then report back with what they say.

My thoughts were that the 32 equivalent, added to the lower magnification (72/68=1.059, so 32x1.059=33.9), plus the more conservative lines due to the 0.7 setting rather than 1m, would make them pretty close to 35mm, but of course they are not as easy to see as the 35's in the m6!