Pink dots in blown highlights

Software RawTherapee
1

Hello everyone, i’m using a recent build of RawTherapee (RawTherapee_dev_5.8-2285-gd7c073e41_20200703) and sometimes, i get pink dots on blown highlights… My camera is an Sony A6300.

At first, i was thinking that it was related to the highlight reconstruction feature (since i was having pink dots when using color propagation)… But with some research, it doesn’t look like so.

So i’ve dig further and i’ve read that this could be related to focus point and i’ve tried to make them disappear (with more or less success). So, It looks to be related to the demosaicing algorithms used (Amaze, RCB, LMMSE, IGV, VNG4) ? (maybe ?)

An example with color progation :

Color propagation pink dots
Color propagation pink dots1920×1040 409 KB

An example with neutral and Amaze + VNG4 :

Blown Highlight Pink dots
Blown Highlight Pink dots1920×1040 335 KB

Is that a known problem ? Is there a way to solve it entirely ? (i’ve not found the answer to those question so far)

Thanks in advance !

2

Is this exclusive to the dev version of RT? Is it possible that these are hot pixels from your camera?

3

I’ve also tried on RawTherapee 5.8 (from the official website), and i got the same result… I’m not sure those are hot pixel, since the tool to remove them do little to nothing on them.

I was gearing toward the fact that those are artefact resulting from the clipped highlight. I’m actually playing with the camconst.json file trying to understand the impact of the white range (since it looks like it do something on them)…

4

Pink dots sometimes are caused by a wrong (too high) raw white point.