I'm curious about the interest in adapting older lenses for use with new MF sensors, such as the GFX. There's a lot of dialog here (and elsewhere) about that; including the various options and test results, and it seems like even in the past some frustration that Hasselblad and Phase are closed systems that don't allow such combinations. When test results are provided, it's most often about the obvious issues of vignetting, CA, or other characteristics, with no commentary on image quality degradation due to limited resolution of older glass.
My understanding (which might be wrong, so please educate me) is that resolution (lp/mm) of larger format lenses was not as crucial as for small lenses, given the surface area of film available, to still yield a great print when enlarged. Since smaller formats expose over a smaller area, they as a result require higher resolution to deliver a quality print. Is that right? With that understanding, I thought LF lenses usually had lower resolution than MF lenses, which similarly required less resolution than 35mm lenses.
If in fact modern lenses made for digital sensors with smaller and smaller pixel sizes have demanded improved optics for full-frame cameras--and most legacy MF or LF lenses were great, but on much larger areas of film, why work so hard to adapt them rather than use modern MF lenses designed and optimized for current generation MF sensors? It seems to potentially be putting inadequate resolution optics in front of ultra-high resolution sensors.
I recognize that cost might play a factor if one already had film-era lenses with large enough image circles. On the other hand, if I were to consider shelling out the cash for even the lower-priced MF sensors (645Z, X1D, GFX), why would I risk compromising on image quality with less-than-optimized lenses? I can see in the case of Otus, Sigma Art, and Canikon T/S that are modern (and therefore have high lp/mm resolution) why they might be attractive if the image circles would cover the sensor properly, but otherwise don't understand the flurry of activity to adapt old glass.
Thanks in advance for helping me understand resolution and it's effect on digital MF image quality.
Ken