How to Scan Slides at Archival Quality

November 7, 2018 | Filed under: Tech Tips

Like most people, I have a lot of old family slides sitting in my basement and wanted to preserve these digitally in the highest possible quality. I did a lot of research and some trial and error before I found the best answer. This is a guide on the equipment you will need to scan your slides in the highest possible quality at a relatively affordable price.

Types of Slide Digitizers

There are basically three types of slide digitizers. The cheapest option is a slide adapter for a DSLR camera. With this method you are simply taking a photograph of the slide. This is fraught with problems because you need to provide a light source behind the slide. Trying to use sunlight is way too inconsistent. Every cloud passing changes the look of your slides, for instance. Trying to concoct a lighting system for this is way more trouble than it's worth.

There are many standalone units that operate on the same premise, in that they are essentially digital cameras housed inside a dedicated enclosure just for photographing slides. Since they are contained, the results will be more consistent than a lens adapter, but the quality is still limited.

The second option is a flatbed scanner with film and slide capabilities. This is much better than the previous option, depending heavily on the model you get. Most flatbed scanners offer this option, but the results leave a lot to be desired. You would need to get a professional model for this to be a viable option and those run around $400-$800. Something like the Canon CanoScan 9000F or Epson Perfection V800 fall into this category.

Neither of these two options is suitable for true archival needs. For this, you absolutely need a dedicated slide and film scanner. These can scan at a significantly higher resolution and produce amazing results. These used to be very expensive machines, well over $1000, until the company Plustek came along with its OpticFilm line of products, bringing this technology to a consumer price point of under $400.

Archival Equipment

The only remaining question is which model best suits your needs. There are 3 models, the OpticFilm 8100, 8200i SE and 8200i Ai. The main difference is that the 8200i models have an infrared sensor in them, with the Ai model coming with more software and a color calibration target. The infrared channel is used to detect dirt and scratches on the slide, which allows the software a much more robust ability to digitally clean up the image.

Which model you choose is based in large part on the condition of the slides you want to scan. If yours have been stored safely, you won't need a model with an infrared channel. But if yours are covered in marks and scratches, you may want consider getting an infrared model. It gives you more options later down the line if you want to do digital cleanup.

All my slides were stored in carousels and have no damage, so I used the OpticFilm 8100, without infrared, which makes it the cheapest option. I have scanned over a thousand slides with it and haven't had a single issue. Scanning at 7200dpi resolution, the detail is astounding.

It is worth mentioning that the file sizes produced are very large. If you are working on a laptop, you may very well need to get an external hard drive just to store the files. No matter what, you want to get one so that you can make immediate backups. Scanning slides is a slow process, so you are only going to want to do this once.

Software

The scanner comes with a program called SilverFast. Many people swear by it, but for some reason I could never get it to produce really good images. So, instead, I recommend a program called VueScan. This just simply produced a more accurate image and I highly recommend it.

Both of these have an enormous amount of features and have a bit of a learning curve, so you will have to spend some with the manual. They can do a lot of image processing for a ton of different scenarios, but for archival use, most of the features aren't necessary because you don't want to do any image modification. You just want to scan the raw image and save it in a lossless file format.

That last bit is very important. For archival use, save everything in TIFF format. If you were to save these images as JPGs, you are immediately defeating the purpose of getting such good equipment by throwing away image data in those fine details that are so well captured by the scanner.

Once you have that TIFF, you can fully explore the software and create smaller JPGs to send to people in emails or put up on a website.

What is the Best DPI to Scan Slides?

This answer is easy: the highest your hardware is capable of. Yes, there are diminishing returns as you get to very high DPI, but for true archival use, you want the highest detail you can possibly get. Granted, it takes a lot longer to scan at the highest resolution (about 3 minutes per slide), but you only have to do this once, so why not get the very best detail you can.

The Process

Once you have everything set up, actually scanning the slides is a very easy process.

Load 4 slides into the holder. Make sure that the dull side of the slide faces upward.
Clean the slides of any dust or dirt with a can of compressed air.
Insert the slide holder into the scanner until it clicks in place.
Click "Preview" in VueScan.
Check that the slide is level and cropped properly.
Click "Scan" in VueScan.
When the scan finishes, check the result. If there are no problems, slide the holder forward until it clicks into the next slot.
Add any information written on the slide to the filename. Dates, names, etc.
Repeat until you scan in all your slides.

Color Correction

By the very nature of slide scanning, each individual scanner will vary in its color accuracy. My scanner, for instance, tended to scan slightly too red, and it was easily fixed in software by just pulling back the red a little bit.

The OpticFilm 8200i Ai comes with a color calibration IT8 target that can be used to build a color profile of your scanner to get the most accurate color reproduction out of it.

Data Backup

If you don't already have a robust backup system, now is the perfect time to create one. The standard approach is the 3-2-1 backup strategy. This means you have 3 copies of your data, 2 of which are local but on separate devices and 1 that is offsite. For instance, you could have one copy on your internal hard drive, one copy on a disconnected external drive and one copy stored in the cloud. This way if one drive breaks, you have two backups at all times.

With that in mind, at the end of each batch of slides that you scan, make sure to plug in your backup external hard drive and copy them over. A backup drive doesn't do any good unless you remember to keep it updated.

I recommend using a service like BackBlaze to store your data encrypted in the cloud. It's only $5 a month and worth every penny. BackBlaze runs in the background on your computer automatically backing up your files so you don't even have to remember to do the backup. It can be a real life saver if anything happens to your computer.

Shopping List

I have compiled all the products I mentioned into a list so you can easily compare the prices and see what works best for you.

Conclusion

It is a lot of work to properly digitize old slides, but it is worth all the effort. Every time I see a house get flooded in a storm or destroyed in a fire, I just hope that someone had taken the time to preserve their old family memories like this. It's a surprising relief to know that I have all of this digitized and backed up multiple times very safely.

I hope this has been helpful and please feel free to contact me if you have any questions.