How can I prevent or remove hot pixels in long night exposures on a Canon T3i/600D?
Asked 9/23/2016
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I’m seeing tiny bright white dots in the dark areas of my night photos from a Canon T3i/600D. They look different from the brighter reflections in the scene and seem more like hot pixels than normal noise. Is this something I can prevent, or does the sensor need cleaning? If they are hot pixels, what’s the best way to remove them in-camera or in post-processing?
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
9y ago
2 Answers
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Two methods for dealing with hot pixels:
Consider the intended output and if the pixels do not affect it or show up, then ignore them. For example, a printer may not have sufficient resolution or JPEG compression to a lower resolution may eliminate them.
Post-processing with software that provides a hot pixel removal tool either natively or as a plug-in.
It is also possible to limit the likelihood of the hot pixels 'going hot' by reducing the amount of time the sensor is exposed to light. In addition to the somewhat obvious method of using shorter exposure times, avoiding or reducing the use of live viewing modes when composing the shot may also help. Of course, these are trade offs.
Originally by user50888. Source · Licensed CC BY-SA 4.0
user50888
9y ago
0
Generated from our catalog & community — verify before relying on it.
Those bright dots are more likely hot pixels than dirt on the sensor. Sensor dust usually appears as darker spots, not tiny white points.
What you can do:
- Reduce the chance of hot pixels appearing by using shorter exposures when possible and limiting live view use, since heat can make them more noticeable.
- Try Canon’s pixel remapping: remove the lens, attach the body cap, enter sensor cleaning mode, wait about 30 seconds, then power the camera off and back on. Repeat if needed.
- Fix them in post if they still show up. Many editors have hot-pixel removal tools; otherwise use a small clone or healing brush and sample the surrounding dark tone rather than painting pure black.
- Ignore them if they won’t show in the final output. Resizing, JPEG compression, or print resolution may make them invisible.
So: this usually isn’t a sensor-cleaning issue, and you don’t need to paint them all black by hand unless simple remapping or retouching doesn’t solve it.
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UniqueBot
AI9y ago
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