Why did my Canon DSLR suddenly develop many hot/stuck pixels in long exposures, and can they be fixed?
Asked 9/30/2022
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2 answers
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My Canon 1100D is about 12 years old and has been mostly in storage with the battery removed. Recently, while shooting 30-second night exposures at ISO 3200, I noticed a large number of bright hot/stuck pixels across the frame, even in a dark frame with the lens cap on. Older dark frames from over a year ago didn't show this issue. The camera has only had a few daytime uses since then, and I hadn't noticed any problem before.
Is there a known reason a DSLR sensor might suddenly show many hot/stuck pixels after sitting unused? Is there anything I can do to reduce or fix them? Running the normal sensor-cleaning function hasn't helped.
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
3y ago
2 Answers
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I'm not aware of any common cause for stuck pixels appearing.
Many report that Canon bodies attempt to map out hot pixels during manual sensor cleaning. The method is to place the camera into manual sensor cleaning mode for ~ 10 seconds. It may help, and it may take a few attempts... there are a lot of videos/etc about it online.
The other potential fix is to record raw images; because some (most?) raw editors look for hot pixels during demosaicing the raw data and automatically map them out. Adobe Camera Raw does this (LR/PS/Bridge); but only for single stuck pixels in isolation (because pairs could be scene detail).
Originally by user70370. Source · Licensed CC BY-SA 4.0
user70370
3y ago
0
Generated from our catalog & community — verify before relying on it.
What you’re seeing is most likely hot pixels, which become much more visible in long exposures and high ISO. They can seem to appear “suddenly,” especially if you only notice them when shooting dark frames or night scenes.
There isn’t a well-known single cause from storage alone, but it’s not unusual for older sensors to show more hot pixels over time.
A few things may help:
- Try Canon’s pixel-remapping behavior: on many Canon bodies, entering manual sensor cleaning mode for about 10 seconds can trigger the camera to map out hot pixels. You may need to try it a few times.
- Shoot RAW if possible. Many RAW converters automatically suppress isolated hot pixels during processing.
- Note that normal sensor cleaning won’t fix this, because the issue is electronic, not dust on the sensor.
If the pixels remain visible in normal photos after RAW processing, the sensor may simply be showing its age. But if the issue is mainly in 30-second ISO 3200 shots, that’s generally a demanding scenario where hot pixels are expected to be most obvious.
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AI3y ago
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