Apochromatic refractors (APO´s) for astrophotography 

The refractor follows the classic telescope design -  a long, thinner tube pointing into the sky and an eyepiece at the bottom. The incident light is collected by the objective, consisting of one or more lenses. Apochromats are refractors (APO´s) whose lens design is designed to combine at least three colors (red, green, blue) into one focal point. This corrects the chromatic aberration (a shift in colors, fig. A) typical of refracting telescopes.

fig. A: Example of chromatic aberration

fig. B. Stars without shift in colors

Coronado SolarMax III 70 mm H-Alpha Solar Telescope with BF15 Blocking Filter

Technical details:

  • Diameter of the objective: 70mm

  • Diameter of the etalon filter: 60mm (Band width: <0.7 Ångström)

  • Clear aperture blocking filter: 15mm
  • Focal length 400mm
  • Aperture ratio (f / 5,7)

Baader Fluorit Flatfield Converter 3x bis 8x Barlow Linse

The FFC allows the focal length to be significantly extended without affecting the sharpness of the image.

A Barlow lens is an optical component that is inserted between the eyepiece and the focuser. Inside there is a negative lens that extends the focal length   of the telescope.

OMEGON Apochromatic refractor Pro APO AP 104/650 ED Triplet OTA

Technical details:

  • Aperture 104mm
  • Focal length 650mm
  • Aperture ratio (f / 6,25)
  • Triplet lens with FPL-53 and FPL-51 elements
  • Tube diameter 114mm
  • Tube length (retracted) 564mm
  • Tube length, with dew shield fully extended, 635mm
  • Weight 5560g

ZWO  Electronic Filter Wheel 5×2″

Monochrome Camera:

ZWO ASI 2600 MM Pro Mono

Technical details:

  • Sensor: Sony IMX571 (back-illuminated CMOS mono sensor)
  • Sensor size: 23.5 mm x 15.7 mm, diagonal 28.3 mm
  • Pixel size: 3.76 µm
  • Resolution: 26 megapixels
  • Pixel array: 6248x4176 pixels
  • Exposure Range: 32 μs to 2000 s
  • Frame rate: 3.51 fps
  • Cooling: Powerful Peltier cooling - 35 °C below ambient
  • Readout noise: 1.0 to 3.3 e-
  • Sensitivity: Peak 91 % QE
  • Zero amp glow design: Yes
  • Window type: anti-reflective coated
  • Anti-dew measures: Anti-dew heater, 5 W, can be turned off
  • Data interface: USB3.0 (USB2.0 compatible)
  • Power consumption: 12 V, 3 A (power supply not included)
  • Telescope connection: M42x0.75 female thread