When you change ISO you must change shutter speed or aperture to keep the same exposure. Enter your current settings and the new ISO to get the equivalent shutter speed (same aperture) and the equivalent aperture (same shutter).
Great for night photography test shots: shoot a fast high-ISO frame to check composition, then convert to a clean low-ISO exposure.
How it works
t₂ = t₁ × ISO₁ ÷ ISO₂; N₂ = N₁ × √(ISO₂ ÷ ISO₁).
FAQ
What is the high-ISO test shot technique?
Shoot at ISO 12800–25600 for a second or two to check framing at night, then multiply the time by the ISO ratio for the final low-ISO exposure.
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