sayjames 寫:
Looks like it's time to upgrade the camera body.
The 3 charts have totally different characteristics.
The first one with the 50/1.4 lens, with gradual increase of F stop number, the focus shifts in a linear fashion. It means, with this lense, I should try to set aperture to 3-4.5. It is bad for the money I spent for a F1.4 lens.
The second one, lens 18-55mm, has front focusing problem.
The third lens, the 55-250mm, is right on. If one tests the camera with this lens, the result will be perfect.
Since I have little knowledge about lens and camera mechanics, I cannot say if this is a camera issue or lens issue. However, I know with the 55-250mm lens, the camera can focus. The same camera with the 18-55mm, the focusing can be consistently off. With the 50/1.4, it is more complicated.
Before chatting with Canon techs, I would like to know from fellow photographers how bad the charts look. If anyone have tested his/her machine or is willing to run a test, I'd love to know the results. If is very good to know how our machine performs after all.