A tip on using the golden spiral or golden rectangle guides

[DPP++]

When you use the golden spiral as a guide of composition, and if you have the choice to define a crop ratio (for instance if your image is to be displayed on the web and not to be printed on a particular format paper), it is better to define a crop ratio of 16,18:10 or 10:16,18 to achieve the best possible approximation of a golden spiral. This ratio is the golden ratio.
Don't define the ratio as 1,618 : 1 or 1:1,618 because DPP will replace it by 1,62:1 or 1:1,62.