Dear all,

measuring VTT target images I found the following
image scales and their uncertainties:

TESOS WL
---------
dx = dy = 0.0897321 +- 0.00142122 arcsec/px

TIP He IR
---------
dx = 0.447180 +- 0.0130805 arcsec/px
dy = 0.386273 +- 0.0170388 arcsec/px

Ca IR (PCO camera)
-------------------
dx = 0.445085 +- 0.0227072 arcsec/px
dy = 0.342069 +- 0.0154266 arcsec/px

This shows that TIP and PCO camera have
very similar image scales. What is more
important, this measurement confirms
the TIP image scale of dx = 0.45 arcsec/px,
dy = 0.35 arcsec/px used in xdr files which
Palo provided me in Potsdam.

An upshot is that the height of TIP scan
is about 34 arcsec indeed and not 47 arcsec
suggested by hair distance in slit jaw images.

Regards,

Julo