#40. "Use of FoCal's QoF values in an absolute sense..." In response to In response to 17
San Jose, US
Larry and I have agreed on the following joint statement:
So far our test results indicate FoCal’s absolute Quality of Focus (QoF) metric is affected by so many variables, many of which we don’t fully understand, that FoCal cannot be used for any comparisons other than LOCAL (i.e., for a fixed test environment and the same operator). Automatic Focus Fine Tuning (AFFT) determination, Sharpness vs aperture and multipoint AF sensor testing appear to yield valid, repeatable results. Also lens csharpness omparisons and body comparisons appear reliable and valid in a LOCAL testing environment. HOWEVER, comparing absolute QoF values obtained by, for example, Pete in CA and Larry in FL, CANNOT be regarded as valid – even ‘tho many attempts have been made to duplicate test conditions and settings.