What’s it all about? These tools make a simple assumption, namely that in digital photography: Interpolation of pixels is a Bad Thing If we map a single source pixel directly to a single output pixel, it follows that a particular scanner & printer combination will yield a single optimum print-size from a given source image-size - anything larger and the system is inventing information, anything smaller and information is being discarded. These tools help you to work out that optimum size. Much of the effort and calculation-work in the spreadsheet is concerned with trying to establish the printer’s actual performance - both inkjet and laser technologies can only approximate continuous tones by either dithering groups of pixels or varying the diameter of each printed dot. Hardly any printer manufacturers quote the effective resolution of the combined hardware & driver-software system, so we’ve had to make some assumptions - see the notes on the “Digital...” page for more information. It’s important to note that this is no more than a starting-point - a purely theoretical optimum. Many other factors influence final image-quality, and when rectifying certain types of problem (such as Grain Aliasing) pixel interpolation can actually be beneficial. We encourage you to use your judgement in identifying what works best with your setup and images. |
