Here is an interesting test that I encourage all imx294 owners to try at home.
I setup the QHY294 on a lens then pointed the lens at the blinds in my home office. This provided a nice contrasty reference image.
The curious thing that I observed is that if I left the lens uncovered, then capped it and took a 4 second shot right away, the 4second dark showed a ghost image of the blinds. The subsequent darks were always OK with no residual image.
Being familiar with RBI on my CCD sensors I tried the same trick at different temperatures from ambient +/- 22c to -20c. The temperature didn't seem to affect it. It always happened, even at 22c.
Here are the reference shot and the ghost image. What is interesting is that all I had to do to create a ghost image was to uncover the lens without taking a frame.
What tipped me off on this was the fact that when doing plate solving, the first image after a slew showed faint trails of bright stars. I though it was the mount settling time so I redid the experiment waiting a couple of seconds for the Mach1 to settle but that didn't change the trails.
Anyone want to try this?
I don't think that in practice this really impacts the images (maybe flat frames?) but it's interesting nonetheless.