SkyWatcher Refractor Esprit 120 ED APO optical tube

SkyWatcher offers a wide range of apochromatic refractor optics, with triplet optics and ED treatment . This treatment ensures the correction of the image aberrations , since it avoids an undesired dispersion of light, achieving a much greater sharpness of the image in its entire field. The image field that is achieved, due to the field flattener , is completely flat.
The optical tube 120 Esprit ED, has an opening 120mm focal length of 84 0mm and focal ratio of 7. This short focal ratio makes it particularly suitable for use in astrophotography. It incorporates a 9x50mm finder, 28mm LET eyepiece and focuser Crayford dual speed model, Track, which ensures smooth shift focus and 0 therefore more accurate.

The lenses in contact with the exterior have an anti-reflective coating, which ensures maximum light transmission, by a factor close to 99.5%. This treatment is called high transmission metal treatment. The objective lens cell is set up to reject residual light that is not focused. The tube itself is designed with internal baffles to ensure maximum contrast , eliminating unwanted light.
Includes Crayford Dual Speed 1:11 focuser with 360º rotation and 1.25 "and 2" adapters, Di-Electric 2 "diagonal, 28mm LET eyepiece, M-48 doublet field flattener and aluminum case.
Characteristics:

• Apochromatic refractor optical design
  
• Diameter / Opening 120 mm
  
• Focal length 840 mm
  
• 240x maximum magnification
  
• F / F / 7 Ratio
  
• Right Angle 8 x 50 Range Finder Erect Image
  
• Diagonal 2 "90 degrees. Diagonal dielectric with 1.25" adapter
  
• Focuser Diameter 3 "Power linear focus mechanism
  
• Eye piece 2 "LET28MM
  
• Barlow N / A Lens
  
• Tube 11kg Weight
  
• The dimensions of the tube 155x750 mmcm3
  
• Shipping weight 15 kg
  
• Steller's weakest magnitude 12.5
  
• Shipping dimensions 122x45x47cm3