| 
			 
			The results, in the 
			above table, are for a single field-of-view and do not suggest that 
			one software package is better than another. Additional FOVs showed 
			that the results vary greatly. 
			 
			The Star Count column indicates the number of identified useful 
			stars by eXcalibrator for color 
			balancing. The data show that the major factor in star count is the 
			accuracy of the Position Angle.  
			
			With the above data, 
			eXcalibrator calculated identical color balance ratios in all five 
			cases. 
			 
			The table also shows that using the Astrometry.net default settings 
			can produce inferior results. The declination is off by one 
			arc-second with a significant error in the PA. Additional tests show 
			that it is better to select the 
			Source Extractor option on the Astrometry.net upload page. The 
			results can be significantly improved but never reduced.  |