COPYING SLIDES...

I have often found a need to copy colour slides. I've used two
methods. One is very simple and will work for odd copies, or if
the slide to copy is larger than 35 mm. - the other uses a
purpose
built slide copying unit.

SIMPLE.....

Find something translucent. The material used for the white part
of backlit shop signs is ideal, but pieces cut from certain types
of margarine container, for example, also work !

Tape this to a CLEAN window, backlit by the outside ambient
light. A cloudy bright day gives the best colour.

Attach the slide to this material with tape or Blu-Tak.

THE CAMERA... Set up the camera, it must be on a tripod again,
with the camera back parallel to the slide. Now, the trick is to
fill the camera frame with a sharp view of the slide.

This will, almost certainly, mean some close up attachment - the
best of which will be a macro lens, closely followed by extension
tubes.

As an aside, you can use this method to put slides onto video, as
video camera lenses usually focus close enough unaided. That is
also, basically, how I digitise my prints - but with front
lighting.

SET UP.. Once a full frame image has been obtained, focus and
stop the lens well down to provide sufficient depth of field. If
you are doing full size copies of a 35 mm. slide, you are at 1:1
copying ratio. This could be a 50 mm lens on 50 mm. of extension
tubes. The depth of field is only about 5 mm. at F22 !!!!!

Try to keep any other light from entering the lens - you could
have a black card surrounding the slide to aid this.

FILM..  This is exactly as for print copying. Slides could be
copied as slides, or as mono or colour prints.  It is possible to
buy special slide copying films, manufactured by Kodak. These are
specially made to be used with flash OR floodlights and require
the use of colour printing filters. They reduce contrast as the
major problem in slide to slide copying is that contrast can
build up.

EXPOSURE..  Try metering and exposing. If auto is to be used, set
f16 and release the shutter by cable release or with the delayed
action setting. The exposure time is likely to be quite wrong.


AUTOMATION ?  At one time I built a quit HEATH ROBINSON rig that
held the diffuser and slide whilst allowing me to place a flash
behind it, flashing as to give back lighting. Some test exposures
were made at fixed aperture with the flash at various distances.
All measurements were carefully noted and, once a correct
exposure
is known, the gadget can be set up the same way each time.



THE EXPENSIVE WAY......  Can be much better if you expect to do a
lot of copying. There are gadgets available that fit onto the SLR
body in place of the lens. These have in built close up lenses,
focusing sliders, slide holders and diffusers. They may be able
to
hold filters and have zoom capability.

These units work very well, and are really a more satisfactory
version of the home built unit described. At least, you are part
way to a consistent set up with these, and a quick copy can be
done by simply fitting the desired slide, checking the focus, and
releasing the shutter with the unit pointing at the sky. As the
position of slide and film cannot change, long exposures are less
of a problem

However, given time, I still use a tripod and pre-set flash
distance, even with these units. The secret of success is, as
ever, to be consistent, and keep a note of all settings.