Slide Scanners

The Plustek 8200 SE slide scanner kit. Image: Plustek

I am related to a historian, who is enthusiastic about transportation, especially trains and aircraft. Many years ago, he approached an octogenarian about borrowing some slides and other documentation, of transportation infrastructure from the 1950s. This person informed the historian that he had thrown out his slides, because he knew they were worthless, but had kept the slide frames, because he knew that they would be valuable. This event probably took place about 2010.

At the time, we had just purchased a slide scanner and had copied some of our 4 000 slides, taken over a period of about 30 years. This may not seem like a lot of photos, but in these ancient times, one had to pay for rolls of film, as well as for the development, not to mention the frames. Fortunately, those days are past. Today, even old phogies constantly use a hand-held device that functions not only as a camera, but as an audio and video recorder. The world moves forward, sweeping the older population along with it.

Just to make sure everyone is on the same page, the purpose of a slide scanner is to transform analogue format images, typically preserved on 35 mm slides, less often film negatives, into digital images. The pixel quality of a slide generally exceeds that of images taken with a contemporary smartphone.

Our first slide scanner, a Jobo SnapScan 9000, was able to scan analog 35mm slides and store the digital content on a SD card in the form of a 9 megapixel image. The manufacturer would have us believe that this resolution was sufficient, and that the scanning process was both Quick & Easy. It wasn’t. Because the scanner operated independently of a computer, users were forced to preview scanned image on an insufficiently small LCD screen. The entire process was a nightmare, that required the user to follow a complicated procedure. We found it necessary to have this written on paper.

This scanner is still available for purchase today, but if readers are contemplating the acquisition of a slide scanner, it is probably better to have one that connects directly to a computer. This will allow the scanned slide to be evaluated at a higher resolution. The images can be scanned as files in an appropriate image format, that can be saved in folders and subfolders that are organized as the user wants. This process is similar to how images are saved to a computer, when a smartphone is connected using a USB cable.

Thus on 2022-02-04, we acquired a new slide scanner, a Plustek OpticFilm 8200i SE, that can scan negatives and slides in about 113 seconds. Yes, you will need at least two minutes to process each slide, but to calculate time use, allow at least three minutes. That is, 20 slides in one hour. A project involving 4 000 slides will take 200 hours = probably many months.

The scanner has a built-in infrared channel to detect surface dust and scratches. This is very useful to remove defects without retouching images.

The resolution is 7200 x 7200 dpi (69 Megapixels) for 35mm negative film and mounted slides. Not all of this will be used because the image on slides is rectangular not square, 24 x 36 mm. The system allows for a 48-bit input, and a 24/48-bit output. In addition, there is up to 3.6 Dynamic Range Enhanced Multi-Exposure Function for improved image quality.

Software includes Plustek QuickScan and LaserSoft Imaging Silverfast SE Plus. Out of the box, these support Windows 7/ 8/ 10/ 11 (64-bit). Mac OS 10.7 ~ 14.x usesr can download drivers from the Plustek website. Linux users would find it better to install a dual boot system with Windows, or borrow a Windows computer.

This software provides multi-format output options: JPG, TIF, PCX and BMP. The SilverFast® SE Plus 8 software helps the cleaning and detailing of the scanned images. The machine was made in Taiwan.

Once slides have been converted, they can be manipulated digitally, just like any other digital image. Red eye issues, and other imperfections in the original image, can be corrected. One can crop them, make collages or introduce other fake elements, if that is desired. Different versions can be constructed for different purposes. Colour filters are often useful, to create monochrome or brightened variants. Enthusiastic users can undoubtedly find artificial intelligence (AI) options to fulfill their desires, but this will have to be done with software that is not part of the Plustek system.

While the slides themselves may be regarded as a backup, physical slides degrade over time. Digital files don’t, but have other issues. The use of a network attached storage (NAS) server, has been discussed previously. Regardless of whether a person uses that approach, or arranges backup in other ways, the 3-2-1 rule still applies: Keep at least three (3) copies, store two (2) backup copies on different machines/ types of storage media, with one (1) located off-site. If you have a good relationship with family or friends, offer to store a copy of their photos (and other important documents) while they store yours.

While some scanner manufacturers claim to automatically upload files to cloud-based storage services, this is not necessarily appropriate, for one never knows how they will be used, or how many others will be able to access them. If a cloud service is to be used, it should only be trusted with encrypted files.

Another benefit of scanning slides, is that it eliminates the need for yet another device – the slide projector. These can be difficult to find, and the situation will only get worse.

A slide scanner is not just useful for slides, it can be used to digitize negatives. These will be processed to reverse colours so that the result appears as if they were slides. As fewer and fewer people actually use photographic film, it is becoming increasingly more difficult (and expensive) to have images printed from negatives.

Beyond the Slide

A slide scanner will not help anyone wanting to preserve printed photos. For this the device to choose is a flatbed scanner. For most households, the quantity of photographs is so small that there is no need to invest in a more expensive sheet-fed scanner. These are also notorious for damaging photos when they are inserted into the device. Models with dust and scratch removal capabilities, only remove these defects from the digitized images, not from the originals.

Some flatbed scanners come with a film attachment, which allows slides and negatives to be scanned.

The scan area of a flatbed scanner is typically letter size = 8.5 x 11 inches = 216 mm x 279 mm used in North America or A4 = 210 x 297 mm = 8.27 x 11.69 inches, used in the rest of the world. There are also A3 = 297 x 420 mm scanners, and larger units but these are disproportionately much more expensive.

Images should be set against the top and one side edges of the flatbed. Glass should be cleaned to remove dust, and prevent damage to the original photo/ slide/ negative. Images should be scanned individually. Image quality, especially in terms of its relative lightness or darkness can be examined using the histogram feature on the scanner preview screen. A scanner is just a camera, by another name. An 8-bit mode image gives 256 discrete brightness levels between absolute black (0) and absolute white (255). Traditional (but now antiquated) light meters used with 35 mm, and other cameras, typically measured 18% gray, the mid-point between black and white = 128. This encouraged photographers to expose at the mid-point, to take advantage of the camera’s dynamic range. More extreme exposure, will limit the device in its ability to record the image.

The histogram, a prominent tool for photography and digital image processing, is a graph that displays brightness levels from the darkest to the lightest, arrayed across the bottom from left (darkest) to right (lightest). The vertical axis (height) shows the relative proportion of the image that can be found at any particular lightness level.

Scanners (and many cameras) have a range of about 5 f-stops, where each f-stop is a doubling or halving of the amount of light hitting the sensor. Some photographers eliminate the top and bottom three values, then divide the remainder into five zones 50 levels wide, that they label  very dark/ dark/ medium/ light/ very light. This accounts for 3 + 5 x 50 + 3 = 256 levels. In contrast, the human eye, is capable of discerning the world in about 10 f-stops of light.

Archival copies of images should be saved in PNG = Portable Network Graphics format. Wikipedia lists the following reasons for using this format: portability, with software and hardware platform independence; completeness, allowing truecolor, indexed-color, and greyscale images; an ability to code and decode in series; progressive presentation, that allows for an initially image approximation of the entire image that is progressively enhanced; transmission error detection; losslessness, all information is preserved; efficiency; efficient and consistent compression; easy implementation; interchangeability, with any PNG decoder capable of reading all PNG data streams; flexibility, allowing future extensions and private additions without affecting the previous point; and, freedom from legal restrictions, the algorithms used are free and accessible.

Log images as they are digitized, and develop an appropriate filing system. This can save time, used with unnecessary re-scanning. Scan everything and keep it. Digital storage space is cheap. The Backup 3-2-1 rule states: Make 3 copies of everything you care about. Use 2 different storage formats. Keep 1 copy off-site.

It should be noted that many Apple and Adobe products deliberately make working with PNG difficult. Resulting files are larger than necessary, because these companies have a vested interest in other formats, such as TIFF = Tiled Image File Format.

A New Computer

Some people like to make their life complex. There was a time when one could say that there were two types of people: those who use Apple products, and those who use Windows. This was obviously before Android and Chromebook. Having a Commodore Amiga as a first computer in the mid 1980s, has made dualism a non issue. We have owned Apple products, including iPhones and Macbooks. We have used Windows machines at work and privately. We have owned a Chromebook. Yet, Linux is our go-to operating system.

Unfortunately, Linux does not work effectively with a Plustek OpticFilm 8200i SE, or its SilverFast SE 8 software. One approach for Linux users is to transform an older machines into a dedicated Windows machine, but with Winaero Tweaker installed, to make it livable. Advice to others: If Windows 7 or an even earlier version is to be used, keep it offline.

What to do after scanning

A person with a slide scanner, and experience in copying their own slides, is a person with a valuable resource, especially for older people who have not made an effective transition from analogue to digital. Volunteering to help others, can begin by letting others know you have equipment and skills available.

Once slides have been digitized, more work can be done if the resulting images are considered digital assets. This topic will be taken up in a future post, partially written but with an unscheduled publication date, titled Digital Asset Management. Part of this post will also deal in greater detail with volunteering, helping others to digitize their slides, and helping people to share them.

This post has had a long development. It was originally written 2021-05-30, but modified 2022-04-15 when new content was added. It was updated once again, starting on 2023-11-09.