I just took a few long exposure photos (exposure between 5 and 8 minutes) with long exposure noise reduction turned on, and notice that some hot pixels remained.
This is the second A7RIII I have and it didnt happen with the other one (images would come out with no hot pixels at all). Is this a bad copy or did I get lucky with the first one?
Also, I'm not sure if that matters, but the lens cap was not on when the camera was taking the second exposure for noise reduction.
Using dark frame subtraction would be a problem for me because I keep the filter adapter on all the time, and wouldn't want to take it off everytime.