貧金屬
Another flash composition common among amateurs consists of magnesium powder and potassium nitrate. Other metal nitrates have been used, including barium and strontium nitrates. Compositions using nitrate and magnesium metal have been used as photographic flash powders almost since the invention of photography. Potassium nitrate/magnesium flash powder should be mixed and used immediately and not stored due to its tendency of self-ignition.