In an interesting **paper** by Antilogus, * et al* subtle effects of electron interactions inside the CCD material itself are discussed, which could be a tool for understanding and perhaps quantifying CCD nonlinearity.

We have tested our own Andor BU987 CCD camera for these effects and see them.

*Plots of row- or column-neighbour means vs correlations. Top row: first panel: full set of values of means vs column-correlations
– we note the strong non-linearities that set in at about 50.000, and
some outliers.
Top row: second panel: for just the range of mean values below the onset
of non-linearity a robust regression is performed (red line).
Bottom row: same as top row but now for row-correlations.
We note the general correspondence to results in the ‘brighter-fatter’
paper: rows are more strongly correlated with their neighbours than are
columns – the ratio of slopes is about 2.0.*

Can this be used quantitatively to correct for non-linearity in our CCD? The camera linearity was already tested for linearity while in Lund. See Figure 8 in the **report.**

Hi! Thanks for your comment! We will discuss it and get back to you. How did you find our blog entry?

Cheers,

Peter