Leica M8 35mm equiv. - 24/25mm or 28mm?

[Bob Ross]

Another way to look at this is to relate it to the sensor size and capture field. A 35mm on FF gives you a field whose long side is almost equal to the subject distance (35FL>36sensor long side). With the M8 the long side of the sensor is 27mm, so the 28mm lens will do the same thing (28FL>27sensor long side).
This can be good for framing before you put the camera to your eye.
The 35mm lens on the M8 is about twice the short side of the sensor, so the short side of the capture field will be half the subject distance. Example: to capture an adult full head to toe, you might want a 7ft capture frame. A landscape shot with a 35mm lens could be taken from 14ft. With a 28mm lens in portrait orintation it could be done from 7ft. Knowing the distance allows you to preset the distance, so all you have to do is tweak it, at eye level.
One point in favor for the 28mm is that the 90mm framelines approximate the metering zone. Anothe is that at infinity the actual capture field is outside of the framelines, but stll in the finder field.
Bob

 

[efix]

Another way to look at this is to relate it to the sensor size and capture field. A 35mm on FF gives you a field whose long side is almost equal to the subject distance (35FL>36sensor long side). With the M8 the long side of the sensor is 27mm, so the 28mm lens will do the same thing (28FL>27sensor long side).
This can be good for framing before you put the camera to your eye.
The 35mm lens on the M8 is about twice the short side of the sensor, so the short side of the capture field will be half the subject distance. Example: to capture an adult full head to toe, you might want a 7ft capture frame. A landscape shot with a 35mm lens could be taken from 14ft. With a 28mm lens in portrait orintation it could be done from 7ft. Knowing the distance allows you to preset the distance, so all you have to do is tweak it, at eye level.
One point in favor for the 28mm is that the 90mm framelines approximate the metering zone. Anothe is that at infinity the actual capture field is outside of the framelines, but stll in the finder field.
Bob

Bob, thanks a lot for your elaboration! Wow, there really still is a lot to learn about the physics involved in photography 🙂

 

[Alberti]

My argument goes for the 28 (*Biogon in my case) and I almost never use a 25mm lens. The 28 has just that little extra sense of DOF (or should I say, shallow image plane) than a little bit wider lens like a 25mm. And this was even with F 5.6.
Look how apt the sense of the frame is.

albert

 

[Bob Ross]

Bob, thanks a lot for your elaboration! Wow, there really still is a lot to learn about the physics involved in photography 🙂

It is just plane geometry, rather than physics, but it is a good trail through the woods of crop factors and format variations. It works just as well with my Fuji 67 and its 90mm lens. It skips all the equivalent focal length mental games and addresses what you have in your hand and where the heck you have to stand to get what you have in mind.
Bob