Symptoms
- Speckled, grainy texture visible in darker areas of photos
- Colors look blotchy or less accurate in dim lighting
- Noise much worse indoors or at night than in daylight
- Noise increases as ISO setting is raised
Likely causes
- CommonHigh ISO setting needed to compensate for low lightHigher ISO amplifies the sensor's signal along with visible noise.
- CommonSmall sensor size struggling with light-gathering abilitySmaller sensors, common in phones and compact cameras, show more noise at a given ISO.
- PossibleUnderexposed image being brightened afterwardBrightening a dark photo in editing amplifies noise significantly.
- PossibleLong exposure heat buildup in the sensorVery long exposures can introduce a different type of noise called hot pixels.
- Less commonSensor or processing fault causing excessive noise even in good lightWould show clearly abnormal noise even at low ISO in bright conditions.
What to do
- Use the lowest ISO setting that still allows a usable shutter speed for the lighting.
- Use a tripod and slower shutter speed instead of raising ISO when the subject is still.
- Expose the image correctly at the time of shooting rather than brightening a dark photo afterward.
- Use noise reduction settings in-camera or in editing software, balancing noise reduction against detail loss.
- Add more light to the scene if possible, such as a lamp or flash, rather than relying on high ISO alone.
- Compare noise levels at the same ISO in good daylight to confirm it's expected behavior rather than a defect.
- If photos show excessive noise even at low ISO in bright, well-lit conditions, have the camera sensor checked professionally.
Tools and parts
- Tripod (optional)
When to call a pro
If noise is clearly excessive even at low ISO in bright conditions, a camera repair shop can check the sensor and image processor.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.