Problem with Sony A7R III Long exposure noise reduction

[zzzbob]

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.

[WB5AGF]

On 7/9/2019 at 2:41 PM, zzzbob said:

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.

Hi - Supposedly there is a 'work-around' that triggers a Sony cameras' hot-pixel mapping routine.

You go into the camera's menu and set the date to some future period (a month-or-two). Then cycle the camera's power on-off. When the camera is turned off there is supposed to be a noticably increased delay from when you turn the power off and the 'thunk' is heard inside the camera. Then turn the camera back on and go into the date/time menu and set it back to the present. At this point the camera is supposed to have remapped its sensor's hot-pixels.

I'm curious ... what kind of 'filter adapter' do you have on your camera ?

- Paul