1.23m-telescope on Calar Alto

 


 

 

 with

without

Corrector
Aperture 

mm

1230
Focal length

mm

9807.6

9857.1
Central obscuration

mm ø

582
Eff. coll. area

0.922
f/ratio  

1/8
Back focal distance

mm

852.1

849.9
Focal range

mm

± 200
FOV
arcmin

90.2

90.0
 

 mm

257.2

258.1

 Aberration free

arcmin
 

 15
 

mm
 

43.0
Scale

"/mm

20.9
Hourangle range

 h min

 -15:06 to +14:50




Corrector Details

  Lens 1 Lens 2
Diameter 290 mm 280 mm
Aperture 276 mm 258 mm
Shape convex concave, spherical biconcave, spherical
Center thickness 25.1 mm 24.4 mm
Surface antireflective coating on both sides, reflection minimum at 550 nm antireflective coating on both sides, reflection minimum at 550 nm
Material Quartz glass Quartz glass




Image of 1.23m-telescope (354 kByte)