CCDinspector was used to determine the collimation of the RC's optics using data from a 30 second self guided exopsure.

The system is set to less than three arc seconds, which is on a par with typical seeing of around 2.5 arc seconds.

Fine tuning of the field flattner required the flattner to CCD plane distance top be optimised

The above 17.4% curvature was reduced nearly by a factor of 2x (below) once the optimum spacing was determined.

Equipment: RCOS 14.25, SBIG STL11000

Check your monitor, can you see all 26 gray scales below?