Hey,

I have been using the 16x manual since a half a year back. Well I always thought that the focus was spot on, since I made it through a
resolution chart over and over again on a production monitor. But after the last adjustment, things haven't really looked that sharp,
and the dof (that blurry out of focus) have been looking rather bad.

So I readjusted it again today with huge success. I used a description and a Siemens Star from: Ron Dexter (http://www.rondexter.com/professional/equipment/adjusting_back_focus.htm) site.
It's amazing how much focus adjustment I didn't see on my other resshart. So my only advice to rookies like me is to use a Siemens Star.

It's really intresting how much this back focus can have influence on, the overal picture is clearer, the dof is nicer.

Take care

I still want to figure out how to backfocus my auto lens on my XL1s... I don't want to have to send it in everytime I need it done :( I'm worried about when support is EOL'd.

The techs at canon can do it which means technically we should be able to do so also.

A Siemens star is most assuredly the way to go. I've even used a PDF of a Siemens displayed on my monitor--not ideal, but it works quite well in a pinch.

Cole: There's definitely no way for a "layman" to adjust the flange back on any of Canon's XL autofocus lenses. Since the ability to do so is not made explicitly available to us, I wouldn't risk giving it a try even if I knew how the Canon techs do it. If nothing else, it would void your warranty.