Here’s a surprise: I made two versions of the same scene.
Using my Nikon Z6-III with a 50mm f/1.4 NIKKOR lens mounted securely on a tripod, I exposed two nearly identical photographs. The first was made at ISO 3200, f/2.5, with a shutter speed of 1/5 second. The second was made at ISO 100, f/2.5, with a shutter speed of 6 seconds.
Both images were exported directly from the original NEF RAW files using identical processing settings. Signficantly, neither image was processed with DxO PureRAW to reduce noise or the effects of lens defects. (So: What you see is what you get).
Can you tell the difference?
When viewed at full size, which one do you think appears sharper?
Tracking the Light examines the relationship between exposure and ISO.
Footnote: I asked the ChatGPT AI engine to analyse my post and my results; it came up with this answer:
One technical observation: all else being equal, the 6-second exposure at ISO 100 is theoretically capable of slightly greater image quality because of its lower noise. However, if there is any vibration, wind, or subject movement during those six seconds, the ISO 3200, 1/5-second exposure may actually look sharper. That makes your comparison especially interesting because the answer isn’t always what people expect.
