Diazo & Silver Film
i) Diazo Film
This is a very low cost copying medium with up to 50 years archival life. For normal commercial purposes this is the ideal economical, very hard wearing, copying medium. Diazo film is processed using ammonia gas or liquid to produce either a blue or black image from the original film.
ii) Vesicular Film
A duplicate made with vesicular film automatically reverses the
image, ie. a negative original produces a positive vesicular copy.
(Vesicular film is not recommended for copying positive originals)
Vesicular film produces a white image on a powder blue background
from the original film. Processing of this film is completed by
heat alone-no ammonia is needed. It is a low cost copying medium
with 10-20 years archival life.
iii) Silver Film
Silver duplicating film is available in 2 formats;-
a) Positive Print Film - to produce a duplicate that is opposite
to the original (ie. negative original changed to a positive copy).
b) Direct Duplicate Print Film - where the duplicate is the same
as the original (ie. a negative original produces a negative copy).
Compared with diazo and vesicular duplicating film, this is a more expensive
duplicating process but has exceptional image quality and an archival
life of 100 years+ when filmed and stored properly. It is an ideal
archival storage medium.
The Microfilm Shop offers a complete diazo, vesicular and silver duplicating
service.
Colour Striping - diazo and vesicular only.
One of the most popular formats of diazo and vesicular duplicating
film is 105mm rolls or 105mm x 148mm sheets, commonly referred
to as microfiche. The Microfilm Shop has the facility to convert
diazo or vesicular into rolls or sheets with colour stripe, if
required. The colour stripe is used to make indexing simpler by
allocating subject groups a particular colour. These stripes are
available in a variety of widths and colours depending on how
much eye readable information is printed on the heading stripe
at the top of the microfiche.
Stripe Widths Available
2mm, 4mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm,
17mm, 21mm, 25mm
.
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A=Red
B=Maple Leaf Red C=Blue D=Dark Blue E=Cambridge Blue F=Yellow G=Green H=Dark Green I=Orange |
J=Purple
K=Dark Brown L=Black M=Chartreuse N=Light Blue O=Light Green P=Pink Q=Brown (Tan) R=Grey |
S=Buff
T=White U=Peach V=Gold W=Lavender X=Violet Y=Cerise |
 |
||
Note:
The colours shown above are meant as a guide only and are not
considered to be a detailed representation of the exact colours
available.
105mm Rolls
These can be supplied colour striped in either 'A' or 'B' wind format
depending on the set-up of your duplicating machine. Please see
diagram below.
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105 X 148mm Sheets (Microfiche) Standard Formats
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Cut
Corners
One corner of each diazo sheet is normally cut off. If the cut corner
is positioned to the top right then the emulsion is on the reverse
side of the material.
Chemicals
Diazo
duplicating film uses ammonia to develop the film once it has
been exposed. The Microfilm Shop can supply a full range of ammonia
liquids and gases. Also available is absorber (DABSORBER) which
is used to absorb excess ammonia during the development process
thus avoiding unnecessary ammonia fumes.
Also
available from The Microfilm Shop is a special transfer paper
(DDODTP) which has ammonia crystals impregnated into it. By the
use of a special heated roller machine the transfer paper is placed
on top of an exposed, but undeveloped, microfiche and inserted
into the machine. By a combination of pressure and heat, the ammonia
is released from the paper and develops the microfiche. The use
of this paper significantly reduces the amount of ammonia in the
working environment. Contact us,
for details of this special equipment as it does not appear in
our equipment section.
Silver duplicate film requires developer and fixer.
Fiche Labels
Fiche labels are available in 127 x 11mm size (JLF) on sheets of computer
stationery. These are ideal to place over old or incorrect existing
headings.
Camera Films
What is a Camera Film?
Camera film or silver halide film, is the original film that is loaded
into your camera when you are microfilming your documents and
is therefore the basis of every microfilm system.
Types of Camera Film
i) 16mm film
Held
on a spool, 16mm films are usually on a 2, 4 or 5mil thick base
and many lengths are available to suit particular applications.
The most commonly used are 30.5m (100ft) and 61m (200ft).
ii) Specialised Cartridge films
In these applications the unexposed 16mm film is pre-loaded into
a cartridge. Although this makes loading film into the camera
easier it usually ties you to a single supplier. In Europe Bell
and Howell's cartridge PAK film is usually Fuji and the 3M G01
film has varied between Kodak and Agfa (and back again) over the
last few years. The Microfilm Shop is able to supply both types
of cartridge loaded with any of the three makes of film.
iii) 35mm film
These are usually used in 30.5m (100ft) rolls for flatbed cameras or
cut into frames and mounted onto aperture card/camera cards.
iv) 105mm film
105mm film is normally cut into sheets, 105mm x 148mm, for use in a
variety of microfiche cameras.
v) COM film (Computer Output Microfilm)
A specialist product, which has different emulsions to the conventional
films included in this section.
Types of Emulsion
Most films are available with a choice of two types of emulsion.
i) High Speed Emulsion
As a general rule these films are used in Rotary Cameras. This type
of camera has an exposure time whose duration is dictated by the
constant speed at which the camera physically transports the document
past the film. Therefore, to ensure quick filming a high speed
emulsion is needed.
ii) Medium Speed Emulsion
As
a general rule these films are used in Flatbed Cameras. This type
of camera usually controls the exposure time to suit the document
and light source whilst the document lies on the camera bed without
moving. Medium speed emulsions have a smaller grain size thereby
tending to give better quality images at the expense of the speed
of filming.
Film Brands
The Microfilm Shop is able to supply every make of film available
i.e. Agfa, Fuji, Kodak or our very own Microfilm Shop film.
Chemistry
Once
your documents have been microfilmed (photographed) onto the roll
of camera film, the film will need processing using developer
and fixing chemicals in a darkroom environment. This can be achieved
using your own processing equipment or The Microfilm Shop offers
a processing service.
The
Microfilm Shop supplies a full range of developing and fixing
chemicals including Agfa, Fuji, Kodak and The Microfilm Shop branded
chemicals.
Both
the developer and fixer can be supplied in concentrate or ready-to-use
format. Also available are The Microfilm Shop mini kits which
provide all the chemicals required for smaller desktop processors.
Processing Supplies
We
can provide all of the consumable items required for a processing
department including film handling gloves, processor leaders,
control strips, test wedges, self-threaders, self-adhesive processing
tape and postal return bags.
Resolution Test Charts
Resolution
Test Charts can, and should be filmed onto your roll of microfilm
alongside your documents. Once the film is processed the Resolution
Test Charts can be viewed on the microfilm to evaluate the quality
of resolution of the roll of microfilm. Resolution Test Charts
are essential for high quality microfilm production. A full range
of these test charts and density patches are available from The
Microfilm Shop depending on your camera type.
Endorser Plates and Ink Rollers
The
Microfilm Shop can provide various endorser plates and ink rollers
for the following camera makes:- Banktec, Buic, Bell and Howell,
Brandt, Canon, IBM, Kodak, NCR, Billcon, Maverick, Minolta and
Unisys.
Densitometers
Essential for quality control checking of the density of your finished microfilms.
The Microfilm Shop can provide a complete range. Click
here to see details of the HE610 projection-densitometer.