Appendix C: Minimum Object Resolution
Barbara Ballard · 2007
Minimum Object ResolutionWhat is the smallest object that can be seen in a given image?The answer drives decision-making on composition of shots, and is not something that most photographers have considered.Professional equipment is aimed at generating content for higher resolution display devices such as standard television.Camera professionals have an intuitive sense of how large an object has to be on the screen to work well for the viewing audience; this sense will not necessarily provide a satisfactory small-screen consumption experience.This appendix provides easy approximations for estimating whether or not a given camera shot has a chance of being usable on a mobile device.Note that this is not a problem when authoring content using the same device as the target audience, since what the photographer's screen displays reflects what the viewer will see.The equations below presume digital image capturing, thus eliminating such traditional technical film photography factors as film grain size, chromatic aberration.Pixels, both in capture and display, are the limiting factor.For the minimum resolution for a target device we need to know the following:• the angle of view of the lens creating the image, AoV • the distance from the lens to the subject, D • the pixel dimensions of the target display, the narrower of PixelsWide and PixelsHigh • angle of view from camera specification. Designing the Mobile User Experience