awilder
Alan Wilder
Anyone know if the GF1 with Panasonic M adapter will allow correct focus with a CV 15/4.5 or ZM 21/4.5 to infinity? With a 2x crop factor, are they effectively f/9 lenses wide open or still f/4.5? Will these slow lenses allow focusing through the finder or will it be too dim?
JoeV
Thin Air, Bright Sun
They still focus the same distance between the lens flange to the sensor, so an F/4.5 lens is still an F/4.5 lens, just with a smaller sensor that intercepts only the center portion of the image, giving you an angle of view equivalent to a lens of twice the focal length on a FF 35mm format camera.
This is assuming that your M/u43 adapter is machined to proper dimensions and tolerances. There have been some reports of issues with certain brands of adapters; you'll have to search this and other sites for info re: adapter brands.
Don't be surprised if you find the resulting images less than what you would otherwise expect; many of these wide angle RF lenses produce soft edges and corners on u/43, due to the sensor requiring a more telecentric lens design, such that the light strikes the pixels more directly. The Lumix 20-F1.7 lens outperforms many of these legacy lenses, albeit with software correction included.
~Joe
This is assuming that your M/u43 adapter is machined to proper dimensions and tolerances. There have been some reports of issues with certain brands of adapters; you'll have to search this and other sites for info re: adapter brands.
Don't be surprised if you find the resulting images less than what you would otherwise expect; many of these wide angle RF lenses produce soft edges and corners on u/43, due to the sensor requiring a more telecentric lens design, such that the light strikes the pixels more directly. The Lumix 20-F1.7 lens outperforms many of these legacy lenses, albeit with software correction included.
~Joe
squirrel$$$bandit
Veteran
They focus fine to infinity--a little past on most adapters, as they have a bit of wiggle room built in. They are still f/4.5, and you can focus pretty comfortably through the VF in good light. I wouldn't depend on manual focusing in, say, a bar at night, though.
EDIT--cross posted!
EDIT--cross posted!