Hi Andreas, that's a very important point. I had thought about it but in the wrong way, assuming that 1.5 was the telescope diameter. So I put 2.2 in its place. Of course I expected an area, not a length, but I thought there could be some justification, and just reserved to look into this question later.

So, thanks for pointing it out. This implies that our efficiency is down by a factor of 2.65/2.2=1.2, so instead of a peak of 8% we have a peak of 6.6%  

I really hope it is just a question of waiting for good seeing. Otherwise, it could be a misalignment of the incoming beam with the fibers (since the fibers are still the old ones). However, Alain did the laser alignment with M2, I could not follow this, but I assume he did it right. Some losses are expected due to the new ball microlenses, e.g. the glue that is used to fix them to the fiber entrance, and to fill the space between the surfaces. Alain said that he used the "super-duper" optical quality glue, and I don't know how much this would affect the light transmission.

Anyway, let's wait for a good night, and if the efficiency is still low, then we'll think about possible problems.

Surfing the web, I found these two references. Did you see them?

http://www.astrsp-mrs.fr/projets/corot/meeting/cw2/mantegazza.html
http://www.usm.uni-muenchen.de/people/korn/korn2001.ps.gz

As another point: in "your" Messenger paper
(http://www.kis.uni-freiburg.de/~setiawan/messenger.html)
you say

"When rebinning the wavelength within the FEROS pipeline DRS, if the command "REBIN/FEROS" is used, this will apply the barycentric correction also to the simultaneous Th-Ar spectrum. This should be corrected with the next MIDAS release. "


Is this still true?

Ciao ciao, Ivo.