Definition of guide number in English:

guide number

Syllabification: guide num·ber


  • A measure of the power of a flashgun expressed in meters or feet.
    More example sentences
    • Such technical items as ‘guide numbers’ don't seem to matter any more.
    • Unless you're shooting under those conditions, consider the guide numbers to be estimates.
    • Small flashes have guide numbers ranging from 45-80, while large shoe-mount units will be up to around 130.

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Word of the day skosh
Pronunciation: skōSH
a small amount; a little