Checking lists to organise the internal workflow, and to outsource the work
Checking lists help to control whether all the important aspects of a scanning project have been thought of. The following lists are not exhaustive. They concern the collection to be scanned, the physical state of the objects, the scanning instrument, the scanning order, parameters for the evaluation of collection segments etc.
- Checking lists to prepare and organise the workflow
- Check what in the collection has also to be scanned:
1.1. Is contextual information available on the object, which should be scanned as well: e.g. a text that accompanies the slides series? Should it be scanned together with the slide(s)? Should it be scanned at a later moment?
1.2. Are supplementary objects in 3D to be photographed: e.g. the box containing the slides or the lantern it was once sold with?
- Check the physical state of the object:
2.1 What positive aspects may the scanning have for the artefact: e.g. to rescue of the image on the slide from vanishing (due to acute and heavy disintegration)?
2.2 What negative aspects may the scanning have for the artefact: e.g. damaging the integrity of the object by putting it in the scanner?
2.3 Is the object dirty and should it be cleaned before being scanned? If it needs to be cleaned, will this eventually damage the slide?
2.4 Does it have to be repaired before the scanning? Should it even be restored?
2.5 What is best for the material that has to be scanned: to be handled now? In the near future? Much later? Not at all?
- Check what has to be scanned how:
3.1 Is the object translucent (thus ideal for reproduction with transmissive light) or opaque (thus better captured with the help of reflective light)? Is the object’s surface heterogeneous (possibly use two digitising methods: one scan perpendicular from above, one photo from a different angle with a different lamp (spot) to show structures in the frame and image), or homogeneous (one digitising method)?
3.2 Is the slide flat or voluminous (three-dimensional)? Can all information desired be retrieved with the scanner or does the object need additional digitisation with a photo camera? If three-dimensional: should this quality be kept in the reproduction?
3.3. Is the slide small enough to be put on the scanner? Will its proportions leave enough space around its edges for an “overscan”?
3.4 Is it movable and will this quality be adequately reproducible by the scanner?
3.5. Is the slide only black and white (no greys)? Does it contain e.g. (simple) drawings and diagrams that ask for a correct reproduction of lines, dots and surfaces?
3.6. Does the slide show variations in grey (grey scale or half-tone images) or is it purely black and white? Does it contain nothing than black text on an otherwise empty (thus 100% transparent) glass?
3.7. Is the slide a positive which may be difficult to reproduce correctly due to aspects such as half-tones, “faded” looking pastel colours, weak / hard contrast? Does it have large transparent and opaque areas which may risk clippings in white and black? (When only two “tones” are registered – white (full light) and black (absence of light) – scanners can have difficulties to reproduce pure black and pure white.) Are these characteristics historical traces which should be preserved / erased in the reproduction?
3.6 Is the slide a black and white negative that will be difficult to scan due to its weak / hard contrast, narrow / wide grey scale, or just monochrome appearance with large black and white areas which may not be correctly reproducible?
3.7 How many “slide sets” (e.g. images of a specific collection, slides produced by the same company) can be created that ask for the same scanning parameters, allow one scanner setting and make the naming of the files easier? This is an essential point for a successful workflow.
- Check the order of the scanning (workflow):
4.1 Does the scanning have to be done in two or more batches?
4.2. Which part of the collection should be scanned first, which second etc.? Is there any reason to deal with one part first?
4.3 How large is the working space? How many slides can be kept “on location” to scan them all in one “portion” (to keep the setting for slides that are more or less identical in their materiality)? Can they stay there for a while or does the scanning have to be done in a specific time slot as other archive departments need the scanner?
4.4. Does the workstation and digital asset management have enough free memory to receive the scans? For how long will their digital storage space be sufficient?
4.5. Will the workstation be needed for more than just quality checking (once the scanning is done)? Is in-house post production intended? Right away after digitising the slides or later?
4.6. Which staff members will be involved in the whole process besides the operator: e.g. to fetch and bring back the slides (storage department), to clean them (restoration department), to re-name the files (documentation department), ingest them in the media asset management (IT department) etc.
4.7 What would be the fastest / safest / simplest / cheapest way to organise the scanning process: e.g. steps needed for a smooth workflow, analysis of potential critical moments, planning of convenient moments during the next 12 months to do the scanning etc.
- Check the parameters to be used for (different parts of) the collection:
5.1 What will / should be done with the scans? How should the scanner be programmed to achieve this?
5.2 Do different parts of the slide collection need different scanning parameters? Which could these be?
5.3 In how far will this influence the workflow?
5.4 Will the parameters chosen for capturing support the technical needs of the post production work? Will the scan quality be sufficient for all the applications planned?
5.5 What would be useful for the future users of the scans (archivists, researchers, publishers etc.): e.g. to scan the slide with a rule (to show the dimensions of the slide) and a colour chart (to give colour parameters for orientation), to scan the whole slide (with some space around the edges to recognise the state of the protection paper and the precise form of the frame) and not only the image, to scan the slide from two sides to preserve inscriptions, embossed signs etc.
5.6. What can’t be reproduced with a scanner (e.g. manufacturer’s details on the small edges of the frame) and which slides need another solution (photographing)?
- Checking list to prepare the scanning area
- Is there enough space for the operator to move easily around the scanner without the risk of damaging objects? Are all potential tripping hazards eliminated to avoid accidents?
- Is there enough space to set shelves / tables to keep the slides to be scanned separate from those that have been scanned already (to avoid double scanning)? Where can the slides be put to acclimatise properly before being photographed?
- If working with control monitors: does the light situation in the working space suit the necessary standards (low / dimmed light of one kind of lamps, no direct light falling on the monitor)?
- Are there enough light sources (to be switched on/off) to make the working space bright enough: e.g. to read inscriptions on (wooden) frames, to control the order of the delivered slides etc.?
- If mass scanning is needed: is the arrangements of the shelves / tables practical to avoid unnecessary coming and going between them?
- If different operators work on the same “batch”: how can be made sure that all concerned parties are informed about what has been done already or has still to be done (communication procedure)?
- If the scanning has to be interrupted temporarily: how to make sure that the interruption doesn’t cause problems for the staff members or for the material, e.g. can the operator leave her/his stuff in a box / drawer? Is there a facility and a procedure to protect the not yet scanned slides to avoid bringing them back into (cold) storage?
- If additional photographing is needed: where to keep a still-camera and a repro-stand with good light sources easily available but not staying in the way?
- Checking list to prepare the scanning session
- Check the cleanliness: scanning pane, light unit, closing lid and slide should be absolutely clean from dust, particles and finger prints; if not, clean them from dust with “liquid” (compressed) air and from finger prints with a clean kitchen towel (to leave no fuzz) to avoid annoying retouching work.
- Check that the scanner is programmed according to the standards set by the archive. Homogeneity in settings will also allow migration to be done later automatically.
- Make sure that the scanner is cleaned after each scan as e.g. dust, dirt, loose colour particles, dirty finger prints, hair, fluff etc. will be reproduced in the digital copy as part of the slide.
- Check whether the glass pane has scratches. If so, change it to avoid that black marks from the scratches have to be eliminated in post production.
- Make sure that working rules given by the archive are respected before, during and after scanning (e.g. that gloves are worn when handling slides).
- Make sure by implementing the latest “Profile Connection Space” (PCS) that the colour information is translated correctly between scanner, workstation and other devices.
- Make sure to calibrate the scanner (before each scanning session) and the monitors used in the workflow (daily), otherwise the registered brightness, hues and contrast may not be reproduced correctly and may lead to erroneous manual programming. If for instance a digital screen (television) or a beamer is used for quality checks, they have to be calibrated as well. It is important to guarantee that the screen is clean and the monitor the brightest light source in the room.
- Don’t forget to adjust the white balance to counterbalance a possible tint of the scanner lamp.
- Make sure that workstation, external hard discs and other digital storage means have empty memory capacity to receive the scans during the (whole) working session.
Hints by the scanner operator:
These recommendations are taken from different books written by specialists in digital reproduction. They complete advices published in the section “Recommendations and general remarks by the working group of “A Million Pictures”, the persons responsible for “Lucerna” and the Trier “eLaterna Archive”, as well as practitioners who scan and photograph slides.
- What to check when the scanning is done by a professional company
“Heritage institutions can undertake digitization and data conservation themselves, provided they have or can obtain the necessary infrastructure, knowledge, funding and staff. The volumes of media that are to be digitized must be sufficiently large in order to exploit economies of scale that justify such a move and the associated expenditure. Otherwise, it is more cost-effective and reliable to delegate the task to specialist service providers.” (Jarczyk et.al. 2017, p. 24) In their analysis, the Swiss authors of the Memoriav recommendations on scanning film (http://memoriav.ch/recommendations-dafv-en/) examine carefully the question “In-house or outsourcing?” When working with a professional service provider, it is important to frame the “relevant requirements” in a contract or a written agreement. It should clearly define what the supplier has to do, and should not do. The Swiss cultural heritage institution also recommends strongly to include quality control in the specifications.
It is necessary to make sure that the following deliverables are agreed on by the service provider:
- uncompressed (“raw”) data (e.g. RAW- and eventually TIFF-files) as “preservation file” and a “proxy” e.g. JPEG-files to serve as “access file”; other files can always be produced from the raw scan;
- a colour depth of 48-bit (3 x 16-bit per colour channel) suitable for TIFF; JPEG has only 24-bit (3 x 8-bit) which is not enough for post production;
- information on the scanner that will be used and its potential in resolution, colour depth and density range;
- confirmation that the scanning will be done by the company in-house and under no circumstances will be outsourced;
- confirmation to get test results with slides selected for their high / low contrast, high / low luminosity, missing / good sharpness, strong / pale colours, nuances in details, different forms (sharp edges, circles) etc. (NB: the results should be assessed by more than one staff member).
- confirmation that no (automatic) image correction software will be used without preliminary agreement by the archive to suppress scratches and dirt, enhance luminosity and sharpness or counterbalance colour. (Correction software can limit the potential of the “raw scan”. Besides, all these “flaws” can be treated in post production.)
- if no fixed price per batch is settled: delivery of a price list for all proposed services to make costs transparent (JPEG-files are standard, but TIFF-files may cost more, the carriers may be expensive).
- information about the carrier (external hard disk, CD-Rom, USB-stick, memory card, “cloud” transfer services etc.) that will be used to deliver the scans; the naming of the files by the company is another point to be agreed on.
- information about the time the scanning will take, and about factors (holidays etc.) that can disturb the planning;
- name and contact data of the person(s) responsible for the scanning;
- covenant to provide regular news on the course of the scanning (in case of mass scanning);
- written agreement with the price and scanning parameters, the planned schedule, the quantity of slides that the company can deal with during a given period of time and the intervals in which to bring new slides, receive scans and get back scanned material;
- confirmation that the company has an insurance (in case slides are damaged and have to be restored).
The authors of the Memoriav recommendations propose similar requirements: “If you are working together with a service provider, they must be prepared to provide you with details of their equipment and explain and discuss the signal paths and procedures they use, and this should form part of a work contract. It should also be possible to view their facilities – the details on their website will not usually be sufficient.” (Jarczyk et.al. 2017, p. 30)
- The series “Guides to Quality in Visual Resource Imaging”
The Guides were written by experts on behalf of the Digital Library Federation and other institutions. Although they date from the year 2000 for the reproduction of photographic images, they give valuable advice which can be also used for slides. The idea behind the series is to disseminate information in order to avoid the ‘reinvention of the wheel’: “Museums, archives, and libraries worldwide are converting visual resources into digital data, and in each case managers of those conversion programs face the same series of decisions about how to create the best possible image quality.” (https://www.oclc.org/research/publications/library/visguides/#background)
Linda Serenson Colet (2000) wrote the first guide titled “Planning an Imagining Project”. It contains helpful hints on how to start the digitisation project and what has to take care of when points come up such as “whether the image is being created for a use-specific project or a use-neutral archive”, “whether the project can be done within one’s institution, outsourced to a vendor, or accomplished through a hybrid approach” or “how the digital initiative can support the activities of specific departments and projects within the institution”. It is interesting to check their control lists which go far beyond the short one we have set up for the digitisation of slides.
Colet also gives some general recommendations to guarantee a higher efficiency:
- Set up a physical workspace that is conducive to the safety of the originals and the workers. Digital capture operators should have comfortable work setups when doing repetitive tasks.
- Balance quality controls with production targets for an efficient workflow.
- Chase the bottlenecks in the production flow: as one is removed, another may arise.
- Keep administrative tasks (storing metadata) to a minimum. Unless a dedicated staff member in the studio is assigned to do this in the assembly line, this task should be done outside the studio.
- Consider ways to continue the workflow outside of the studio (storing the master image, disseminating the derivatives, and creating an enterprise-wide solution for archiving and accessing). An institution that is not set up for the massive organization that is required once the digital file leaves the studio, may have to secure outside services for this purpose.
- Organize work in batches (i.e., by size and by like medium) for maximum efficiency.”