TI 55   f/6.5 Astrograph – OPTICAL PERFORMANCES

Telescopi Italiani has decided to show a full review about the awesome optical performances of our TI 65  f/6.2 Astrograph

No other manufacturer shows detailed diagrams like these.

SPOT DIAGRAM

The Spot Diagram and the other performance diagrams, was calculated:

• On Axis (1)
• 11.6 mm from axis – corner of the KAF8300 (2)
• 17.29 mm from axis – corner of the KAF16200 (3)
• 26.10 mm from axis – corner of the KAF16803 (4)
• 30.65 mm from axis – corner of the KAF39000/KAF50100 (5)

TI 65  f/6.2 Astrograph (650 mm aperture- 4030 mm focal length): IT IS REPRESENTED THE SPOT DIAGRAM CONSIDERING THE WAVELENGHT FROM 400 TO 700 nm.

 TI 65 f/6.2 – Spot Diagram

THE GRAPH BELOW SHOWS A  SPOT DIAGRAM vs FIELD UP TO 34 MM OFF-AXIS (68 MM REAL DIFFRACTION LIMITED CORRECTED FIELD)

SPOT DIAGRAM vs WAVELENGTH

A very important diagram that nobody shows. Only after analyzing these curves we can see that the optic is really excellent for every wavelengths. The black line is the Airy Disc radius, the numbers are the five fields.

RELATIVE ILLUMINATION

The Relative Illumination curve is the ratio between  the light hitting the focal plane and the total light  incoming. To obtain a good illumination for this f/6.2 astrograph, was been necessary to optimize secondary mirror diameter, corrector lenses diameter and relative distances. For the TI 65 series, we have the best field illumination still having reduced obstruction.

TI65 f/6.2Vignetting Diagram[/caption]