November 2002 - Splicing Cine Films
Any user of cine film
is at some stage faced with the problem of joining two piece of cine
We have successfully overcome a film breakage
while showing a film by sticking the two pieces of film together with
ordinary self-adhesive tape. This is strictly an emergency measure
however, for film which has passed through the projection gate, performed
to allow the film show to proceed. The splice, not having been aligned
properly, will almost certainly not pass through a gate. The tape
will not be perforated and the adhesive is not heat resistant, so
may ooze out. Any film join made with ordinary adhesive tape should
be replaced by a proper splice as soon as possible.
There are two basic
methods of splicing cine film:-
(a) a solvent which "melts"
the film base is used to "weld" the two pieces of film together.
(b) a specially designed self-adhesive
tape patch is used to join the two pieces of film
Each of these methods has its advantages
and disavantages. There is no perfect solution. Sometimes one method
or the other has to be used - for example, if preparing film for copying
to video, ask the company who will be doing the copying whether they
have a preference for tape or cement splices.
Whether you choose tape or cement, practice
on some old film until you are comfortable with the procedure.
The aim of a splice is to be as unobtrusive
as possible when the film is shown. The splice must be flexible and
strong enough to not break whilst the film is undergoing the pushing,
pulling and sometimes quite rough mechanical handling that it undergoes
There are two reasons for joining films
together. Individual films may be joined together to make a longer
film - this can save money when having film copied to video, for example.
The film may require editing - cutting spoiled scenes out, rearranging
scenes to give a more pleasing effect etc. Again, by removing unwanted
material before having a film copied to video, a cost saving may be
The choice of splicing method may be dictated
by the type of film used. Single-8 film and some Super-8 films have
a polyester base which is not affected by film cement. Therefore these
films must be spliced using tape.
Many people are very happy with tape splices;
others have never accepted them. The theory is that because the tape
forms a very thin layer over the film, the image is moved very slightly
out of the focal plane when projected, resulting in a brief loss of
definition on the screen. There is also a cost to adhesive splices,
which are much more expensive than cement splices.
Cement splicers, when new, ranged in price
from a few pounds to £60 plus. The cheaper splicers make a good,
serviceable join but can be rather crudely engineered and may give
a more visible splice. Better quality splicers give a more accurately
cut film and cleaner scraping of the emulsion layer, resulting (with
practice) in a splice which is almost unseen. The best splicers have
a very small overlap which gives an excellent splice although it can
be weaker because of the very small overlap.
See also Ensign
Popular Cement Splicer instructioons
A tape splicer can be a simple device,
sold at a low price, or a more complex automatic machine. Most tape
splicers give similar results, depending on the care of the operator
to avoid dust, hairs etc, and ensuring that the tape is free from
A problem with tape splices, on some projectors,
is the "hinge effect" at the butt joint where the spliced
film is more flexible. To overcome this, some tape slicers make a
diagonal cut. However, this is more visible on the screen. Most tape
splicers join the film at the frame line which should make the splice
much less obvious, if it is done with care.
See also Quik
Splice Tape Splicer instructions and Quik
Splice Dual Gauge Interlock Butt Splicer instructions
When splicing sound films using tape,
it is necessary to avoid covering the sound track. Special splicers
or splices may have to be used.
Some time ago we
had a request for the "recipe" for film cement. I very much
doubt that the necessary ingrediants are readily available but for
interest only, here it is, taken from. the 1975 Desk Edition of
the Focal Encyclopedia of Photography, under the heading "Film
Cements": My thanks to Roy Salmons (email:
firstname.lastname@example.org) for this.
"There are various propietary film cements available. In all
of them the action is the same; the cement softens the film base as
soon as it is applied, and a few seconds later it is absorbed by the
base. The two halves of the splice must be pressed together while
the base is still in the soft condition. Properly made a splice should
be stronger than the film.
The basis of most cements for nitrate film (now obsolete) is amyl
acetate and for acetate film, acetic acid.
A suitable formula for both nitrate and acetate film is:
Acetone 8 parts
Ether 10 parts
Acetic Acid, glacial 1 part
To this is added about 1 part of 16mm film (with the emulsion removed)
per 3 - 4 ounces (100 c.cm.) of solvent. More may be added to make
a thicker cement."
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