Microfilm Archive for Music Rolls
By Robbie Rhodes
I performed this experiment a few years ago, when a library curator inquired about archiving music rolls. I wonder if there are other related photographic experiments.
Abstract:
A reproducing piano roll, 11.25 inches wide, travelling at 167 feet per minute, was photographed by a 16-millimeter microfilm machine at 1:24 reduction. The resulting microfilm image easily resolved the chaining patterns but did not resolve the scalloping of the continuous slots. Several short blurred regions were attributed to slight slipping of the music roll. A more precise drive mechanism is needed, and it may be necessary to use 35-mm film.
Problem:
Many important collections of music rolls must be archived by some method before the music paper disintegrates from age. Transcribing the music roll to computer file with a pneumatic reader fails to preserve much data of importance, for example: the perforator advance distance (evidenced in scalloping), the design and contents of the label, lyrics stencilled or printed on the edge of the roll, pencilled notations, and evidence of editing, such as adhesive tape and knife marks.
Objective:
Identify and evaluate efficient methods of preserving music roll data to archiving standards, with suitable precision to enable replication of the original music roll.
Approach:
Perform experiments with commercial microfilm machines: photograph a music roll and evalute the suitability of the resulting microfilm image for subsequent optical scanning to computer disk file.
Results (July 1991):
1. An experimental microfilm was made by Microfilming Service, Inc., of
Corona, CA. They are both a microfilm service bureau and retailer
of Kodak products.
2. The music roll was Ampico 206511, "Sometime". Roll condition was
fairly good, with firm edges, length about 25 feet less trailer. The
label on the leader was in good condition, and the lyrics were the
familiar Ampico green color.
3. The piano roll was hand-fed into an old Rekordak Rotoline Microfilmer,
Model RD-3. This machine has a fixed 24:1 reduction ratio (standard)
and transports the original at 167 linear feet of paper per minute.
4. The film used was Kodak Imagelink FS Microfilm 1455, Estar Base,
16mm x 100 ft., Film Spec. No. 615. This emulsion is similar to the
obsolete 1454 fast-speed emulation, with better contrast. The plastic
spool is to an ANSI standard.
5. After the film was developed a few prints were made using an old office
microfilm pviewer/printer onto direct-exposure silver-halide paper.
Comparison prints also were made at the same image size (85%) with an
office copier (direct optical xerographic, not a scanner & laser printer).
6. The image of the roll width on the microfilm was measured at
0.469 +/- .003 inches, which compares favorably with the computed
size of 11.25/24 = 0.468 inches. The reduction along the "long" axis
wasn't measured.
7. The microfilm failed to resolve the little points of scalloping. Also,
the roll took a jump a few times of about 0.180 inch -- one blurred
region is visible just below the pencilled "Paderewski" notation, and
there are others of varying degree throughout the roll.
8. The reduction ratio of 1:24 is the standard for all Kodak 16-mm
microfilm cameras; it's use is recommended.
9. The green lyrics appear fuzzier than the hole images, possibly due
to chromatic aberration.
10. The sales staff at the service company recommended these other Kodak
products for further experiments (unfortunately, none were readily
available at the time):
Kodak Mini Microfilmer -- portable16mm, 12-inch field width, 1:25 nominal
ratio, resolution 100 line-pairs per millimeter minimum, object speed
10 to 15 feet per minute. Price $5000.
Kodak Recordak Rotoline Microfilmer Model RD-3 -- 1:24 or 1:32 reduction
options, 167 feet per minute. (This is the machine used for the above
experiment.)
Kodak Imagelink FS Microfilm 1455, Estar Base, 16mm x 100 ft., Film
Spec. No. 615 -- price about $9 per 100-foot roll, including processing.
11. Another division of Kodak handles optical scanning machines which
create CCITT Group 3 or 4 formatted images at speeds of 18 inches
per second across a 12-inch field.
Recommendations:
The Model RD-3 machine used in this experiment was admittedly old, and it's probable that a machine in better mechanical condition would produce a sharper film. It would be worthwhile locating a machine in better condition and repeating the experiment. It shows good promise.
-- Robbie Rhodes 13 August 1995
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(Message sent Sun 13 Aug 1995, 23:10:57 GMT, from time zone GMT-0700.) |
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