Quote Originally Posted by jrw View Post
Interesting that a humble pencil might work out well. Would want to pay attention to the focus points though....
It seems that my other link is also no good any more.
I think the last time I used a very fine sharpie. On a full frame draw the lines ~1.35mm from center. Us a straight edge when drawing the lines. There is no issue with focus points. If you did not get it right just clean off with glass cleaner and try again. It does not have to be perfect.

IMG_0216 by clemmb60, on Flickr