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What could be causing this in my X-T3.  160ISO, 20 sec exposure, 16-80mm at 22 mm.  Attached is a crop.  Looks like red and green hot pixels.  My film sim is the std default as well.  All photos are raw and edited in lightroom.

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Edited by chrisdennyphoto
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7 hours ago, Olaf W. said:

Did you try pixel remapping? The hot pixels may be gone after that procedure. The X-T3 should remap by itself from time to time but you can force the process from the menu.

Thanks Olaf.  I did the pixel mapping last week.  With that said, these photos are taken in late evening and most long exposures.  Not all my photos have them.  Sometimes its a bright green pixel somewhere in the image and some brighter spots that look like noise but they stand out more prominant and not really in the lower left but lower left is most dominant at times.  Again, this doesn't happen but maybe 1 every 10 shots but its on those shots that I don't want this.

Edited by chrisdennyphoto
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I do not have any good thoughts about how to stop the hot pixels from showing up, but there are noise reduction techniques from astrophotography that may help your images until you are able to get the hardware issue resolved.

Right after taking a long exposure shot (or sequence) put the lens cap back on and take another image at the very same settings you used for the long exposure shot. in your image editing software, put this dark frame as a layer directly above your good image layer. Set the blend mode for the dark frame to “Subtract”. That should take care of a lot of the minor issues and help towardcthe major ones.

Another possibility is to set the blend mode to “Difference” and play with the layer’s opacity setting.

These do depend on whether or not your image processing software allow you to do that sort of thing.

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18 minutes ago, jerryy said:

I do not have any good thoughts about how to stop the hot pixels from showing up, but there are noise reduction techniques from astrophotography that may help your images until you are able to get the hardware issue resolved.

Right after taking a long exposure shot (or sequence) put the lens cap back on and take another image at the very same settings you used for the long exposure shot. in your image editing software, put this dark frame as a layer directly above your good image layer. Set the blend mode for the dark frame to “Subtract”. That should take care of a lot of the minor issues and help towardcthe major ones.

Another possibility is to set the blend mode to “Difference” and play with the layer’s opacity setting.

These do depend on whether or not your image processing software allow you to do that sort of thing.

Actually the setting LONG EXPOSURE NR should do the dark frame subtraction. In my XT30 it works without any problem. That's why you have to wait more than double the exposure time, until the long exposure is finished with this setting on.

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4 hours ago, chrisdennyphoto said:

Ahh man.  I was hoping you would not say that.  I hope thats not what is needed.  Servicing can take weeks.  Just had this thing for a month.

Did you use LONG EXPOSURE NR?? Actually this should remove the hot pixels from the raw and jpeg. 

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18 hours ago, Wolvesgang said:

Did you use LONG EXPOSURE NR?? Actually this should remove the hot pixels from the raw and jpeg. 

this I did not do.  I usually try to temper my noise reduction because l want to control it in post but I will give this a try and see if it keeps its sharpness.

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19 hours ago, Wolvesgang said:

Actually the setting LONG EXPOSURE NR should do the dark frame subtraction. In my XT30 it works without any problem. That's why you have to wait more than double the exposure time, until the long exposure is finished with this setting on.

It can be, if you are shooting a single exposure. If you are shooting a sequence, then things get more complicated. Here is a better explanation:

https://www.cloudynights.com/topic/635338-long-exposure-noise-reduction-vs-dark-frame-subtraction/

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