Amazing lens, incredible sharpness

PaulM2 wrote:

David Kieltyka wrote:

Just to note...the lens doesn't give a rat's dupa what the characteristics are of the sensor or film frame it's mounted in front of. If the ratio of focal length to max. aperture diaphragm size is 1.8:1 then the lens is a 1.8. Period (allowing for manufacturing tolerances and lens maker rounding/exaggerating).

It's certainly a good thing to know that larger photosites tend to be more efficient both at photon collection and in turning those photons into legit image-generating electrons. It's also a good thing to know that using a larger sensor/film frame yields less DOF for a particular field-of-view & f-ratio compared to a smaller sensor/film frame. (Whether or not this second feature is an advantage or disadvantage is up to the individual photographer.) But when taking photos with an m43 camera/lens combo it's also irrelevant. The format is what it is...you go with it and work within its boundaries, same as any other format including 35mm.

-Dave-

With no intent to hi-jack the original post, my 2 cents worth.

I play with old legacy glass from my old film cameras and the above discussion, I have read with great interest.

I have the adapter that allows me to mount, say my 45mm/f2.0 Minolta film lens, to my PEN. With the 2x crop factor in mind, my angle of view or should I say DOF, is equivalent to a 90mm on a 35mm film camera. But the f stop is still f/2.0, as I did not change any of the physical aspects of the lens itself? Its still the same old lens I used many years ago. (the focal length of the lens and the physical size of the aperture determines the "f" number)

Indeed, the lens did not change.  That is, it's still a 45 / 2 -- it didn't change into a 90 / 2 or a 90 / 4.  However, photos at 45mm f/2 on mFT will look remarkably similar to photos at 90mm f/4 on FF -- much more similar than they will to photos at 90mm f/2 on FF.

I fought with this concept in my mind for some time. But when I consider that I must shoot this old stuff in manual mode, set the focus, aperture, shutter speed, ISO, I am lucky to get the first exposure even close.

The exposure will be the same on all formats at all focal lengths for a given f-ratio and shutter speed (ignoring differences in t-stops, of course).  However, the total amount of light falling on the sensor will be very different (as will the DOF).  Of course, if you are not comparing formats, this doesn't matter.

And as a added note, this old lens on the PEN does not work as well as it does on my DSLR. Could be a problem with the adapter? But it was fun to try.

Does not work as well how?

Again, thanks to all who have posted. Very interesting.

Glad to hear it!