The Yashica extender lenses for the Electro 35
Jan 15, 2014 22:45:01 GMT
on Jan 15, 2014 22:45:01 GMT
Last Edit: Jan 15, 2014 22:48:40 GMT by mburns
These lenses have a 55mm thread for attachment to a Yashica rangefinder. and provide a different focal length when attached.
It's been written that these extender lenses have poor optical quality and that they should not be used wide open. Neither assertion is true. They are sharp, do not change the exposure, and do not add more vignetting.
The truth is that the focus distance must be adjusted when these lenses are attached. The new distance for the tele extender is .77 of what was measured, and the adjustment factor is 1.19 for the wide extender. These factors are inversely proportional to the new focal length of the system. Unfortunately the look up tables on the extender lenses are just rubbish.
It's been written that these extender lenses have poor optical quality and that they should not be used wide open. Neither assertion is true. They are sharp, do not change the exposure, and do not add more vignetting.
The truth is that the focus distance must be adjusted when these lenses are attached. The new distance for the tele extender is .77 of what was measured, and the adjustment factor is 1.19 for the wide extender. These factors are inversely proportional to the new focal length of the system. Unfortunately the look up tables on the extender lenses are just rubbish.
