naturephoto1 Offline Upload & Sell: Off
|
rscheffler wrote:
Typically the larger the format, the lower the lp/mm resolving power of the lens because the format itself required less enlargement. This somewhat changed with digital, hence the reason you see the digital optimized lenses for MF back systems such as Alpa and the like. Not saying the Mamiya 80/4 isn't a high resolving lens, just would be surprised if it exceeded many of the better lenses currently available for smaller formats. I think this is also where numbers in isolation don't directly relate to reality. Sharpness is greatly influenced by the entire system used to create the image.
This is the Rodenstock data sheet (pdf) for their analog lenses - for film - note that the MTF graphs top out at 20lp/mm, whereas for 35mm format lenses, Zeiss, Leica, etc., 20lp/mm is in the middle and 40 is typically what is analyzed to death for determining sharpness.
For comparison, here is the data sheet (pdf) for Rodenstock's digital lenses, where they measure 10, 20, 40 and 80! lp/mm. Basically you see performance similar to the best 35mm lenses because the MF digital backs are pretty much super-sized 35mm sensors with similar pixel density and pixel size to current 35mm FF sensors. This was previously not necessary with LF lenses because the film was simply much, much larger than 35mm. But now the digital backs cover a much smaller area than LF film did, therefore require much greater enlargement and much better lenses....Show more →
But the newer Rodenstock and Schneider digital lenses are optimized for close to wide open. Some of the best of the older LF and MF Apo (and Macro) lenses particularly in the 120mm, 150mm, and longer focal lengths should still perform relatively well on the MF digital backs and these lenses were optimized to be stopped down for f22 to f32 for greater DOF. The newer Rodenstock and Schneider WA digital lenses however do not need to be stopped down nearly as much as the longer lenses to maintain DOF
|