2
\$\begingroup\$

I've got a Canon 1100D camera which is maybe getting on a bit at about 12 years old, but it's performed great up to now. I took it out recently though to do some long exposure night shots, and noticed a sea of stuck pixels that seems to have appeared from nowhere. Here's a zoomed in portion of a 30 sec ISO 3200 shot I took with the lens cover on that shows the problem. This is the same all across the sensor:

Stuck pixels

Looking back at some similar dark frames I did over a year ago, there are zero stuck pixels. Since then, the camera's mostly been in storage with the battery out, save for maybe 3 or 4 daytime sessions where I didn't notice the problem.

So is there a reason why a camera might suddenly pick up a load of stuck pixels like this even when it's barely being used? And is there anything I can do about it (I've tried running the built in sensor clean a few times and it does nothing). Or maybe it's time to finally get an upgrade.

\$\endgroup\$
14
  • \$\begingroup\$ Did you check that you get the same stuck pixels in different dark frames? \$\endgroup\$
    – xenoid
    Sep 30, 2022 at 10:46
  • \$\begingroup\$ @xenoid Yes, just did another shot and compared to yesterday's - exactly the same pattern. \$\endgroup\$
    – el_zilcho
    Sep 30, 2022 at 11:47
  • \$\begingroup\$ Are you saving raw files or JPEGs? How are you viewing them? Do you have Long Exposure Noise Reduction (LENR) enabled or disabled? What happens if you take a very short exposure with the lens cap on when the camera is first turned on after having been off for several hours (and cooled to ambient temperature)? \$\endgroup\$
    – Michael C
    Oct 3, 2022 at 16:19
  • \$\begingroup\$ Does the time/date remain correct when you store the camera for months with the batteries removed? \$\endgroup\$
    – Michael C
    Oct 3, 2022 at 16:39

1 Answer 1

2
\$\begingroup\$

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).

\$\endgroup\$
2
  • 1
    \$\begingroup\$ To remap hot pixels with the camera (Canon 1100D), the manual sensor cleaning mode must be left open for at least 30 seconds. One should also use a body cap in a dark room. If light strikes the sensor during manual cleaning mode most hot pixels will not be mapped out, because the entire sensor will have full well values. \$\endgroup\$
    – Michael C
    Oct 3, 2022 at 16:54
  • 2
    \$\begingroup\$ I've tried the manual cleaning thing many times now - all with the body cap on, sometimes for 30 seconds, sometimes for 2 minutes and longer. It makes no difference at all on my camera sadly. Yes I normally shoot in Raw, and the issue doesn't affect images with daytime settings - only long exposures. Maybe I will just have to always take a dark frame afterwards and manually subtract it. \$\endgroup\$
    – el_zilcho
    Oct 4, 2022 at 8:33

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.