----- Original Message ----- From: "Greg Lovern" Subject: *ist D sensor and 35mm lens resolution
I think Rob figured the sensor resolution to be around 45 lpmm. This is pretty close to what a good lens will resolve, and also fairly close to what film will resolve under normal picture taking situations. Lens resolution is tied more to lens design and quality of materials and build than to format. William Robb > The *ist D's sensor has about 43% of the area of a 35mm film frame (369 > square mm compared to 864 square mm). Lenses don't have infinite > resolution; instead they have resolution limits for each aperature. Does > it follow that a 35mm film lens' resolution, when used on the *ist D, will > be 43% of its resolution on a 35mm film camera? (And conversely, that its > resolution on a 35mm film camera would be 234% of its resolution on the > *ist D?) > > If a given DA lens were to be as similar as reasonably possible to a given > 35mm lens, with the sole exception that it's image projected the same > resolution onto the smaller area of the *ist D's sensor, would the sensor > be able to capture 234% as much resolution as it would with the 35mm film > lens? > > If a very sharp lens, such as Pentax's sharpest 50mm lenses (past or > present), loses 57% of its resolution when used on the *ist D, is it still > a very sharp lens? > > I plan to get an *ist D soon no matter what answers I get to these > questions. I'm just wondering what the potential is for DA lenses, all > else being equal, to be sharper on the *ist D than 35mm film lenses. > > > Thanks, > > Greg > >
