Symptoms
- Same colored dot appears in the same location on multiple photos
- Spot more visible in long exposures or high ISO shots
- Dot doesn't move even when recomposing the shot
- Spot not visible in bright daylight shots but shows in dark areas
Likely causes
- CommonHot pixel on the sensor showing up during long exposures or high ISOA single sensor pixel reads brighter than it should under certain conditions.
- CommonDead pixel that always appears black or a fixed colorA sensor pixel that no longer responds to light correctly.
- PossibleSensor needs a pixel mapping or refresh function runMany cameras have a built-in feature to identify and correct these spots.
- PossibleDust on the sensor mistaken for a hot or dead pixelDust spots often look similar but usually appear as darker, larger blobs.
- Less commonSensor damage from extreme heat or a manufacturing defectWould require sensor replacement rather than a software fix.
What to do
- Take a few test shots at different ISO settings and exposure times to see if the spot only appears in certain conditions.
- Check your camera's menu for a pixel mapping, pixel refresh, or noise reduction long exposure feature and run it.
- Take a photo of a plain white or gray surface out of focus to distinguish a sensor spot from dust, which usually looks different in shape.
- If it looks like dust rather than a pixel, try a sensor cleaning function in the camera's menu.
- Update the camera's firmware, since some pixel mapping improvements are included in updates.
- Note whether the spot is always the exact same color and location across many different photos and scenes.
- If a fixed hot or dead pixel remains after pixel mapping, most manufacturers can correct it during a service visit; it doesn't always require full sensor replacement.
When to call a pro
If a persistent hot or dead pixel remains after running the camera's pixel mapping feature, a manufacturer service center can often correct it without replacing the whole sensor.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.