"I have a 210 G Claron in a Copal 1 shutter. I also have a 240 G Claron which I would like to mount in the same shutter. If I do this can I use the same aperture scale? i.e. do the apertures correspond in size between the two lenses? Or, do I have to get a scale specifically for the 240? Many thanks as always........ --Stephen Vaughan, 2004-01-14 01:09 AM
You can do what you wish. There is a correction factor of 1/3 of a stop. The 240 len is 1/3 of a stop more closed down than indicated. ie, When using the 240 in this instance, if the iris says F11, the actual stop is F12.5. Having even more fun, the equal focal length 1/3 stop increments are.... 210mm, 240, 270, 305. Sound familiar? --Frank Filippone, 2004-01-14 04:35:36 "
Can I assume that my Kowa 240 will be 1/3 more open than the Computar 270 scale reads? Thanks - David Kashuba.