LAICA (Large Area Imager for Calar Alto) is a wide-field imager in the whole visible range, placed at the 3.5-m telescope prime focus.

With a field corrector, it covers a non contiguous field of view equivalent of 0.25 sq. degree with its four 4K CCDs representing each 15.5´x15.5´ on the sky, but spaced by gaps of 13.6 arcmin, since the CCDs are non buttable.

In four contiguous pointings, LAICA thus covers a full square degree field with slight overlap between CCDs to check the astrometry and photometry between pointings. These special and spatial characteristics make LAICA particularly efficient for survey observations, like the ALHAMBRA ones.

Available at: Primary focus (f/3.9) of the CAHA Zeiss 3.5-m telescope

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foto LAICA@3.5 prime focus

 In a nutshell

Instrument/Telescope LAICA/3.5 prime focus
Field corrector K3 three-lens (f/3.9)

Four BAE CCDs of

4096x4096 pixels

Field of view 44.4'x44.4' (gaps 13.6')
Pixel scale 0"225 / pixel (unbinned)
Read out time & noise
80 s (unbinned) & 6e-
Intrinsic image quality <0"3
Geometrical distorsions <2% (pincushion)
Wavelength range UV atm. cutoff to 1 μm
Filter magazine
20 bands, see filter list


 Observing with LAICA

Preparing observations During observations
After observing
Requesting observing time User's manual Basic data reduction

Former webpage incl. the manual 

Basic troubleshooting Alhambra pipeline TBC
CCD characteristics Log sheets Alhambra final data release
Exp. time calculator Two guider CCDs (FT mode)
QEs of CCDs #1, #2, #3 and #4
Shutter uniformity: 0.1% in 0.3s   
ZPs (Johnson bands)

Filters (incl. 20 medium-bands)

Service mode observing template

Do not forget to center you target on a given CCD, e.g. #1 with the best cosmetic quality) with @@ center 1


More information


Reference article: MPIA newsletter

Image gallery

Spectacular images taken with LAICA, at times in combination with other

CAHA facilities (see Vicent Peris and Fundación Descubre websites),

including various NASA Astronomical Picture of the day:

galaxies NGC 7331 & M74,planetary nebulae M57 & M97

Calar Alto Press Releases



Ten billon years of cosmic evolution at hand

Alhamba-GOLD data made public

ALHAMBRA: the history of the universe, at sight


LAICA construction started in 1999 by the following team head by the late Prof. J. W. Fried:

  • Construction + mechanics: R.Rohloff, H.Baumeister, W.Benesch
  • Electronics: B.Grimm, R.Klein, C.Unser
  • CCDs: K.H.Marien
  • TV-guiding: U.Graser
  • Software: K.Zimmermann, F.Briegel

LAICA saw first light with test CCDs on 20 May 2001. Then it has been tested - with all CCDs working properly - on the telescope from October 2003, 24 to 27. Clouds prevented tests with star light. The CCD array looked very good, tests of linearity, dark current, shutter homogeneity etc. all gave excellent results. LAICA has been used in december 2003, and worked very well, including the auto guider. The Coma has been removed by alignment of the main telescope mirror. Until summer, we will prepare timings for fast read out, as well as a special timing for low blooming. We will also improve the cooling system.