Hi Mark, One of anything cannot be a pair. You have lines and spaces to work with. A line "pair" cannot be construed to be one line & one space. It's got to be two lines & two spaces. One of each does not constitute a pair; two of each does.
So it seems to me. keith Mark Roberts wrote: > > "Bob Blakely" <[EMAIL PROTECTED]> wrote: > > >The wording, line pairs per mm, implies two black lines and two white lines > >in as much as "pairs" is plural and also because there are many more than > >two lines in the target. This would mean that line pairs per mm would be > >half of lines per mm. > > Hmm. At least one source I've seen regarded one black line and one white > line as a "pair". > > -- > Mark Roberts > Photography and writing > www.robertstech.com
