Microfilming at SVK
Microfilm
Workflow
Microfilm Standards
(i) Choice and
Quality of Film –
For high-contrast archives like text, line drawings and engravings Pan-chromatic AHU microfilm on polyester base works good and recently it has been improved and optimized to a large extend.
For high range of gray or
continuous tones like books containing photographic reproductions or color
material that is to be filmed in black and white, half-tone microfilm such as
Kodak 2468 or Kodak 3468 will be best producing film of positive polarity.
For ensuring best possible quality of the master as well as the
duplicate, a Quality Index of 8 is suggested.
35mm roll film for the master for digitization is the best, which
guarantees sufficient quality even up to larger sizes like 60-80 centimeters.
Along with the quality index, density of the film, resolution and
background shadow should at least meet the ISO standard. Distortions should be
avoided.
(ii) Film Technique
–
Uniform reduction ratio for the complete project as a whole
Uniform positioning of the material, possible optimal position is to
place the material in the middle of the front edge.
Contrast between background and filmed material should be carefully
controlled.
Alignment of the material should be properly checked for the whole
project.
(iii) Organization
and Documentation of the Film –
Take into account take-counters, subdivision of films by indication sheets, placement of blips, and documentation on the filming procedure.
Structuring a film by legible
indications on the filmed material, running take numbers, blips, and
appropriate indications on a take frame.
(iv) Choice of the System
–
The system should guarantee
resolution of at least 120 lp/mm over the entire screen.
For filming books and archival material, the camera should produce optimal results with reduction ratios of between 8 and 24.
For conservation reasons, the planetary camera should also have a device for protecting bindings and book covers, such as a two-part book-cradle with a sufficiently open glass plate with adjustable pressure. It should be possible to film heavier and oversize volumes without damaging them.
For duplicating masters, the film
should be silver-halogenide duplicate film of the same polarity. Duplicating
should be undertaken with high-quality duplicating equipment (working under
vacuum on parallel-running films) to minimize the loss of resolution.
(v) Recommendations
for color microfilm –
For digitization of color film should be a high-resolution, permanent-color bleach-fixing-process microfilm on a polyester film base which should yield a high-resolution, reproduction quality microfilm that matches the quality of black-and-white microfilm.
Use the full-step format of un-perforated 35 mm microfilm
Choice of Color film scanners should meet the minimum requirement of digitizing full-step 35 mm color microfilm and should have good resolution support say up to 2000 dots per inch (dpi) or more