How to digitize old aviation slides?
As soon as photography became accessible to the general public, photos were already taken of airplanes at airshows, military exercises and other events in which aviation played an important role. Unlike today, where everyone with digital cameras or smartphone takes thousands of photos, in the 60s, 70s and 80s a lot of pictures were taken with photo slides or negatives. Because many beautiful photos of military aircraft were taken with slides for decades, these photos never got the attention they deserved.
Photo slides, technically known as reversal films, are a type of photographic film that produce a positive image on a transparent base. Slide film is processed to form diapositives or transparencies, rather than prints or negatives. A photo slide is a specially mounted transparency, designed for projection onto a wall or screen. This makes it ideal for viewing photos at a larger scale and in a group setting. The 35mm is the most common type of slide and is typically housed in a cardboard or plastic mount to facilitate projection. This type of slide film was first introduced in the early 30s but it took until the 1960s for it to gain prominence. After I received a large collection of slides from the late Belgian aviation fanatic René Geivaerts, I bought a semi-professional scanning device and started digitizing these old slides. After scanning these slides, I gave the digital files a facelift in Adobe Lightroom and Adobe Photoshop so that they are ready for their new digital life. In this article you can find tips and tricks on how to digitize and edit old slides to give them a digital makeover.
Cleaning old slides
One of the most important things to do before scanning old slides is to carefully clean them. Old slides can have a layer of dust and dirt or even spots of fingerprints and scratches. If the slides are not cleaned, dust or other spots will be scanned, which will reduce the digital quality of the slide. A good way to carefully clean slides is to blow off the dust and other dirt with a dust blower. This should be done first so that the dust does not cause scratches when the slide is subsequently cleaned with an anti-static microfiber cleaning cloth. Gently wipe the surface of the slide/film until no more can be seen on it and don't push to hard on it. If you want to be completely sure that your old slides are not damaged during cleaning, wear cloth gloves so that the slides are optimally protected. For 35mm mounted slides, remove the film from its plastic or cardboard casing before wiping to avoid just brushing dust and dirt to the edges of the slide. Don’t use water to clean the slide/film. Any water will soften the emulsion and will almost certainly lead to the slide looking much worst than it was to start with.
Scanning old slides
After a slide has been cleaned, it is time to scan it so that the photo can be made into a digital file. To digitize an old slide we can use a slide scanner. There are many slide scanners on the market and my advice about this is to not buy the cheapest one. I bought the PlusTek OpticFilm 8100 which is available at all the better photography stores. The Plustek OpticFilm 8100 is a dedicated film scanner with 7200 dpi optical resolution. Its light sources give images more precise color rendering (48-bit color depth) with less power consumption. The scanner comes with 2 film holders. The mounted slide holder can hold up to 4 slides. The negative holder can hold strips of 35mm film up to 6 frames long. Other manufacturers who develop qualitative slide scanners are Reflecta and Epson. If you use a flat-bed scanner, make sure you also clean the glass of the scanner. You can use an eye-glass cleaner for this but do not spray directly on to the glass.
A scanner alone is not enough to digitize a slide. You also need software that converts the scanned slide into a digital file. The software I use is VueScan which can be downloaded from its website (https://www.hamrick.com). I personally think VueScan is very good and user-friendly software, as you can already make some important adjustments in this program. It is possible to crop the scanned slide as you want and to immediately adjust the white balance or other colors. In addition, you can also select what the scan resolution should be and as which type of digital file you want to save the scanned slide. Another good software program you can use for scanning slides is SiverFast (https://www.silverfast.com/silverfast9/).
JPEG or TIFF
When a slide has been scanned it is recommended to save it as a TIFF file and not as a JPEG. TIFF is a great choice for archiving images when all detail must be preserved and file size is not a consideration. The biggest difference between these types of digital files is that a TIFF is a bigger file size. If you scan a slide as a TIFF, the digital image is going to be about 100 MB. If you scan a slide as a JPEG, it's going to be around 12 MB. Another difference is quality. A TIFF scan will look more grainy because it does have a lot of digital data. JPEGs look more smooth, but less sharp. But, the grain is important because it does add more pixel depth (sharpness). If you're doing any commercial work with your scans, you must save your scans as TIFFs. When you're doing any editing or manipulating your images in anyway, you need as many bits and bytes as you can.
For some people the work will stop when an old slide has been scanned into a digital file. For me, however, the work does not stop as there is still room for improvement on this digital file to make the photo better. The colors of a scanned slide often seems 'old' or 'vintage' and sometimes dirt can still be seen on the scanned slide. Als the brightness and contrast of a scanned slide is not comparable to what we see today with digital photos. Fortunately, these are all things that can be adjusted with post-processing software such as Adobe Lightroom or Adobe Photoshop. I always perform the most important edits in Adobe Lightroom such as adjusting the white balance, exposure, contrast and the white and black tones (screenshot below). I also add some clarity to the scanned slides because a lot of these slides look soft and the clarity tool can fix this. Another important reason why I post-process the digitized slides in Adobe Lightroom or Adobe Photoshop is because I can easily remove any dust spots or other spots. In Adobe Lightroom you can do this very easily by using the 'Spot Removal' tool.
Scanned slides often have a lot of grain and are not very sharp. These things can be adjusted very easily in Adobe Photoshop (screenshot below). By using the filter 'blur surface' in Adobe Photoshop you will remove grain from the scanned slide. You have to be careful to set the values not too high, otherwise you will get a blurry and ugly effect. Then you can make the scanned slide sharper by using the filter 'sharpen' and 'sharpen smart' in Adobe Photoshop.
It will take a lot of time if you want to digitize a lot of old slides and improve their quality. Once you have the finished result you will be amazed of the fact that you can turn an old slide into a beautiful digital image. For example: the slide used for this article was made in 1977 during the Brustem Airshow and showed a lot of problems (discolored and scratches). Nevertheless, we shouldn't expect too much, as a twenty or thirty year old slide can never achieve the same quality as a digital photo of today. Yet digitizing old aviation slides is perfect to give these photos a second life so that new generations can enjoy them.