There are a few simple
reasons that the auto-focus feature on your projector may not
work, or appear to work incorrectly.
First, be sure that
your model projector actually has auto-focus. Many Kodak models
look almost exactly alike, but many of them don't have auto-focus.
Even if your remote control has a focus button that lets you electronically
focus the projector, you may still have a model that doesn't have
the auto-focus feature. The best way to be sure is to check your
owners manual, although most models say auto-focus somewhere on
the projector. Older Kodak projectors which have auto-focus have
a model number starting with 'AF', and the newer ones have an
'A' in the model number(i.e. Ektagraphic IIIAMT). Other brands
designate it in different ways.
Once you are sure your
projector has auto-focus, look for an auto-focus switch on the
machine and be sure it is in the 'ON' position. Many older machines
didn't have this switch and it frequently confuses people that
use a variety of projectors. On older style Kodak projectors,
the switch will be located on the back panel near the power switch.
On newer Kodak projectors the switch is located just left of the
focus knob on the control panel. On Telex/Singer projectors the
switch is usually on the top where the carousel tray is placed
near one of the corners, although on viewer models it is usually
on the side.
The most common problem
with auto-focus on a slide projector is not understanding how
it is supposed to work. Since auto-focus cameras don't require
any user intervention, it is a common mistake to assume slide
projector auto-focus will also work by itself. However, this isn't
entirely true. For proper auto-focus operation the user must be
sure to focus the first slide manually. After that, all the other
slides will be focused automatically.
Another common problem
is having some of your slides inserted differently than the others.
There is a difference between the two sides of a slide, and if
you look real close you will notice that one side is shinier than
the other. If you don't have them all inserted the same way, due
to the way auto-focus works, some of them may be slightly out
The final simple cause
of auto-focus problems is the use of very old or poorly mounted
slides. If your slides are extremely warped due to age or a poor
slide mount, the auto-focus on your projector may not be able
to focus the slide for you. A badly curved, or warped slide will
never be in focus across the entire image and auto-focus can't
fix that. Your slides may require remounting, or may not be salvageable.
The last tip we can
give you on auto-focus is to understand a little bit about how
it works. Auto-focus on a slide projector is done optically, using
light reflected off of the slide emulsion surface. It must be
able to detect extremely small changes in position of each slide.
The mechanism that performs the focusing operation is very delicate
and critically aligned. It can be thrown out adjustment if your
projector is dropped or abused in any way. If your projector won't
focus, but you suspect it may have received an impact, don't conceal
this fact from the service center. Telling them this may save
on the labor it takes to find the problem.