It turns out that many KEE friends are experiencing what we discussed yesterday... So today, let's discuss how to solve it by fine tuning, but remember that you need to understand first if you want to tinker with this feature. If it's wrong, the autofocus could be messed up.
Well, this arrangement was made by Erwin Mulyadi, maybe it can help you. With the 17-70mm lens which experiences back focus in the telephoto position, you can try the AF microadjustment feature on the Canon camera. Let's see how:
1. Go to the menu, look for custom function (C.Fn) select the 2nd line, C.Fn II: Autofocus
Source : http://www.infofotografi.com/
2. From the many options, search for AF microadjustment, 3 options will appear
3. For conditions where the problem is only on a specific lens (not all lenses), select option number 2 (Adjust by lens), then press the Q button.
4. Because the problem is with the telephoto focal point (50-70mm), select T (telephoto), press the Ok button. the following display appears
5. In this display you can adjust front focus / back focus compensation. You can shift to minus for back focus, and to plus for front focus. After that you can try again. If it's still not quite right, you can add the numbers back in. For example, you set it at -2, but it turns out it's still back focus, you can increase it to -5 until you get the right setting.