Anerror in the checking here is taking a picture of a stick laying at an angle. Your senosors form a +, and depeding on your camera the sensor is larger than the little square that you see that highlights. If the left part of sensor focused correctley it would indicate front focus, if the right part focused it would indicate back focus. For instance my 1D IV the sensor is twice the size as the square.


You need to take a picture of somthing in a flat plane, with the ruler set beside it at an angle to get an accurate reading. You could use somthing like lensalign or this [View:http://www.the-digital-picture.com/Reviews/Datacolor-SpyderLensCal-Review.aspx]


You can make a homeade version yourself with a box and ruller.


That said, it does look like it front focused a bit. The real test is in actual use, and you alread have a sense it is front focusing. So if you camera allows, you could adjust it.


EDIT: Just noticed you indicate it does not have an adjustment. Which only leaves sending it off.