Hi Iliah and Ben,
thank you both for your comments. I'll need a little time to digest them,
learning more about RawDigger and flat fielding, and finding out how to mount a
filter on the Solux lamp. It looks like I also have to consider changing from
Iridient to RPP as the raw processor.
Concerning the evenness of the illumination: I think for the actual shot it was
a little better than for the quick reconstruction of the setup I made for the
iPhone shot. For this reconstruction, I did not care to measure evenness with
the spot meter. I have however noted that the 2 Solux lamps have different
color. - For the next year or so, I live in an interim domicile and can not
improve much on the setup, except for the flat fielding and the filter.
Thanks again! - Hening.