Hi Frans,
What precision is necessary for chart orientation estimation?
Focal lengths given by manufacturers often differ from actual focal length
values.
For example a typical 50mm lens is really around 52mm (4% difference). In
case of some zooms the differencies are even greater.
One can also have doubts about the sensor width values. (eg. if sony says
that a7 35,8 mm sensor is 6000 pixel wide, than the DCraw 6048 pixel image
is 36,08 mm wide.
Does a 4 or 5% difference in focal ratio noticeably influence the chart
orientation estimation?
Regards
Jerry
Right now the accuracy of the chart orientation estimation is not great outside of the range I tested; in fact it appears to be rather insensitive to rotation at other focal lengths.
So unfortunately I cannot even give you a straight answer until I fix the problem, and then test with different lenses. This is a pretty big project, and I don't have as much time to work on MTF Mapper as I used to, so I won't make any promises.
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Hi Frans,
What precision is necessary for chart orientation estimation?
Focal lengths given by manufacturers often differ from actual focal length
values.
For example a typical 50mm lens is really around 52mm (4% difference). In
case of some zooms the differencies are even greater.
One can also have doubts about the sensor width values. (eg. if sony says
that a7 35,8 mm sensor is 6000 pixel wide, than the DCraw 6048 pixel image
is 36,08 mm wide.
Does a 4 or 5% difference in focal ratio noticeably influence the chart
orientation estimation?
Regards
Jerry
Right now the accuracy of the chart orientation estimation is not great outside of the range I tested; in fact it appears to be rather insensitive to rotation at other focal lengths.
So unfortunately I cannot even give you a straight answer until I fix the problem, and then test with different lenses. This is a pretty big project, and I don't have as much time to work on MTF Mapper as I used to, so I won't make any promises.
Thank you very much for explanation!