Some fonts come with different optical sizes. A few Adobe fonts have different optical sizes that are recommended for 6–8 point text, 9–14 point, 14–24, and 24+ points. I am designing an A1 poster, which is will not be read from such close a distance as regular text. Most, if not all, text will be set larger than 24 points, and certainly not smaller than 14. Should I use the optical sizes as intended, or should I take the viewing distance into account?
Example: 12pt type viewed from 0.4m subtends an angle of 0.61 degrees, so it looks as tall as 30pt type viewed from 1m distance, which also subtends an angle of 0.61 degrees. If I use 30pt type on the poster, should I use the optical size intended for 24+ points, or the size intended for 9–14 points?