Archived posting to the Leica Users Group, 2001/07/31
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Marvin Levi wrote: > > This is actually rather simple. > Let's compare Mamiya 7's 80 mm F/4 vs > Leica 50 mm f/2 summicron. At optimum > apertures for both, the cron can resolve > 110 lpmm, and 80f/4L can resolve 75 > lpmm. Yes, Leica is better in raw > resolving power. Now, take the size > of the negative into cosideration. > 24x36mm vs. 56x69.5mm, pick > the lowest linear difference (the area > difference is VERY misleading)and > multiply: 110 x (36/69.5)= 57 lpmm for > the cron when enlarged to the same > size as the Mamiya 80mm f/4L. > The winner? Mamiya. > Don't forget also that in terms of exposure > accuracy, Leica's ancient, mechanical > shutter can be off 1/3 EV, while Mamiya's > electronic shutter is about 1/10 EV. If > both were metered correctly, Mamiya will > expose more consistantly which is also > critical for attaining that maximum > resolving power. > By the way, the 110 lpmm is an overestimate, > I've seen literature saying the cron can > do 90 lpmm. I think Erwin Puts said it can > do beyond 100. > Nice numbers. You got matching 20x24" prints in which we all and you can take a Loup and see that the Mamiya makes sharper images? Mark Rabiner Portland, Oregon USA http://www.rabiner.cncoffice.com/