Re: checking backfocus on video cameras in field

Bob,

You must take the chart with you and use it several times each day. Backfocus often change as the temperature does (metal expands and contracts) and obviously you should check it when you change lenses.

The PD-170 and other such cameras don't have interchangable lenses so there is neither backfocus adjustment or the need for it.

Ultimately the best method for checking and adjustment is the special projector attachments made my Zeiss and others and as you note the largest, sharpest monitor available.

JS