Stuart Richardson
Active member
Nick -- digital lenses are more or less a marketing ploy. Lenses are lenses...they can be optimized for one thing rather than an other, but a good lens is a good lens. The concept of digital lenses evolved from large format studio shooters in the earlier days. They were using lenses like the 210mm APO-symmar that you are describing, but they were using it for 24x36mm sensors. The 210mm apo symmar will cover 8x10 inches, and it is optimized for 4x5 -- clearly, it is way too large to be dealing with a 24x36mm sensor, or even a 48x36mm sensor. The lens makers like Schneider and Rodenstock noticed the disparity in the market, so they started to design lenses like the 28mm digitar, 47mm digitar, 150mm and so on -- they were designed specifically with digital in mind -- they had a smaller image circle, but arranged for the light rays to hit the sensor more evenly (normally, large format wide angles had rear elements very close to the film plane -- they are easy to design with high performance on film, but digital sensors do not work as well with them).
But when we come to SLR's, the Rollei lenses for example are already designed to cover 6x6, and the "digital lenses" still need to cover about the same amount. Since it is an SLR, the lenses' rear elements are already fairly far from the film/sensor, so the retrofocal issue that plagued large format lenses is not an issue. Basically, the idea of a "digital" rolleiflex lens is just a marketing idea. This is not to say they are not better, it is certainly possible that they make better lenses and call them "digital", but there is nothing inherent in the design of the old film lenses that makes them unsuitable for digital.
As I said before, the Rollei macro lenses are superb -- so good in fact that they don't need updating as "digital lenses", where the old Mamiya 645 lenses for example needed revamping. The Hasselblad H lenses are of course designed after digital, so their basic design already takes it into account.
I guess my long winded point is that there is no reason to design "digital specific" lenses for a 6x6 SLR -- the image circle for digital is the same size as it was for film, and since it is an SLR, the lenses are already retrofocal enough to avoid the need of a lens redesign. While it is always possible to make better lenses, there is nothing about the current lens line that makes it unsuitable for digital use.
But when we come to SLR's, the Rollei lenses for example are already designed to cover 6x6, and the "digital lenses" still need to cover about the same amount. Since it is an SLR, the lenses' rear elements are already fairly far from the film/sensor, so the retrofocal issue that plagued large format lenses is not an issue. Basically, the idea of a "digital" rolleiflex lens is just a marketing idea. This is not to say they are not better, it is certainly possible that they make better lenses and call them "digital", but there is nothing inherent in the design of the old film lenses that makes them unsuitable for digital.
As I said before, the Rollei macro lenses are superb -- so good in fact that they don't need updating as "digital lenses", where the old Mamiya 645 lenses for example needed revamping. The Hasselblad H lenses are of course designed after digital, so their basic design already takes it into account.
I guess my long winded point is that there is no reason to design "digital specific" lenses for a 6x6 SLR -- the image circle for digital is the same size as it was for film, and since it is an SLR, the lenses are already retrofocal enough to avoid the need of a lens redesign. While it is always possible to make better lenses, there is nothing about the current lens line that makes it unsuitable for digital use.
