You're welcome!
I would like to detail a bit the reasons and causes (of the need or not) of lens resolution.
Speaking about film: basically yes, LF vs. MF lenses do have bigger image circles (thus a bigger lens angle) BUT need less resolution due to the film size used (which "compensates" for this "lack" of resolution), same for MF vs. SF lenses. But this is (IMO) not chosen by the lens manufacturers: it is simply much more difficult, if not impossible to get the same resolution on the whole coverage of such a LF lens (and if possible, at which price?).
Further, LF lenses DO NEED to have much larger image circles as the film size used (4x5", 5x7" or 8x10") to enable doing the movements like shifts, tilts and swings. This is quite different than a given MF lens (or SF lens) which is used on a MF fixed body (or SF fixed body) and without movement possibilities. So there is a kind of compromise made here: less resolution at the edge BUT possibilties of shifts/tilts/swings with a 4x5" film.
It is basically a fact that any good SF lens and any good MF lens will "out-power" a LF (film) lens: they simply don't have the necessary coverage (lens angle) for LF.
If one considers now "LF" digital (understand "LF" here as "view camera"): since the sensors currently used are "much" smaller than almost any given MF film format (6x12; 6x9; 6x6, with the exception of 645), it needs basically less image circle on these "LF" digital lenses, first to cover and then even to allow significant and sufficient movements of the sensor within the image circle. That's basically why the "LF" digital lenses have such a smaller image circle. One does simply not need it to be bigger since it simply needs to cover much less surface. But also important is, that it needs much less shift/tilt/swing possibilities on a smaller capture medium: a Scheimpflug angle of e.g. 5°-10° on a 4x5" format would need about 1°-2° for the same sharpness plane on a digital sensor (for the same image crop).
If one considers now MF digital (without shift, tilt or swing possibilities), then it becomes obviously more logical (for a lens manuacturer) to concentrate the efforts on "narrowing" the lens angle to the specific used sensor size. This is what it is all about with the 28mm Hasselblad. To which extend it has effectively increased the resolving power of this lens by designing it this way, is something I cannot answer (if there is an increased resolution, which has to be proven), for not having been able to compare it with another "traditional" 28mm designed for MF film and then used on such a digital sensor. And to which extend this has an effective and visual effect on the resulting prints, with the current sensors, this is also something which I am unable to say. I personnaly doubt it has. But then again, it is only my personal opinion and "guess": don't put me at the point of your gun.
For me it seems at the moment more important and relevant to have a 35mm lens available for the Hy6, which has certainly (obviously!) a longer focal length then a 28mm BUT, which covers the 6x6 format. That is certainly an advantage for possibly coming larger sensors AND for the use with film. Should a larger sensor come out in the near (or not so near) future, then obviously this very same 35mm will show its full importance and advantage over the 28mm which will be impossible to use on this larger format.
I can however understand the relevance and importance for some users of having a 28mm available now.
Thanks and best regards,
Thierry
Thanks for your feedback. Optical design requires consideration of a long series of trade-offs in design to acheive the desired end result. Time will tell if incorporating software correction into the actual lens design yields tangible benefits in actual application.
Regarding my (over simplified) notion as to why Sinar (and Rodenstock and Schneider) digital view lenses have much smaller image circles than their film counterparts–is the purpose basically to permit higher resolution than is practical with large film image circles?
Some cynic might wonder if digital view lens makers are charging a higher price for less coverage to conceal a devious plot to fool consumers into paying more for less!
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