Quote Originally Posted by BTrigaux


Now time to send it back for calibration.


Any idea about cost of such a service ?





You could send it in now but its not necessarily time. You have a 5D Mark II which can do microadjustment for the lens. You could adjust it yourself and see if you can get acceptable focus.


Take a look at this:


http://www.The-Digital-Picture.com/Reviews/Datacolor-SpyderLensCal-Review.aspx


There have been numerous threads about how to do this on this forum as well. Just do a search of AF Microadjustment also AFMA or MFA.


Three shots really do not establish anything because of other variables involved. For instance light, in lower light your lens may have more difficulty. In this one instance it may have trouble reading the contrast of the subject. A vertical target set at 90% is best. The AF system on the 5D could be considered a precision tool, its not as precise as you think. Of all the tests I have done on my 5D you will get a fair amount that focus exactly where you want, then there is a fair percentage that focus behind and in front. You look for the best average of shots that hit the area you want.


Lighting is a big part. When you set up to do the microadjustment you need it to be well lit. Low light can give worse results.


You should also be shooting in single shot, single point selected mode.


Set the lens as you did to F4


Your set up look very stable. The suggestions I would make is to get a vertical target instead of a flat one. You could buy one of the tools they make, like the spyder or the lens align. Or make something similar yourself. Use a tape or something similar to read the results, but use the flat vertical target to aim. The target should be vertical and level to the camera.


You can go here to find what lensalign recommends for distance:


http://www.whibalhost.com/lensalign/ldt/index.html


Good luck





Rick