Amazing lens, incredible sharpness

Anders W wrote:

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.

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)

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.

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.

More likely, it has to do with the fact that, although it is precisely the same lens, the PEN uses only one quarter of the image circle the lens is designed for and that you need to enlarge that quarter four times more to reach the same display size as an image shot with 35 mm film or an FF sensor.

In fact, here's a good way to say it.  Let's say the FF sensor had the same pixel density and efficiency as the PEN sensor.  Then you could simply shoot the 45 / 2 on the FF camera, crop to the same framing you'd have gotten had you used the lens on the PEN camera, and the photos would be all but identical.

Alternatively, if the FF sensor had the same pixel count and efficiency as the PEN sensor, and you used the 45 / 2 with a perfect 2x TC on the FF camera, the resulting photos would be all but identical as the photos you'd get using the bare lens on the PEN camera.