DIY Slide Digitizer – Jennifer Hodgdon's Personal Site

My DIY slide scanning setup

When I was growing up, my dad’s film of choice was Kodachrome 64 slide film (I grew up before the age of digital cameras). I think he made that choice for several reasons:

When taking into account processing, slides were cheaper than print film.
Slides have very high resolution.
Kodachrome 64 makes great outdoor photos, and my dad was almost always outdoors.
My dad liked to have slide shows.
Slides have a built-in spot for notes — I don’t think this was actually one of his reasons for choosing slides over print film , but it sure is handy, and I’m grateful that he wrote notes on most of his slides.

I’m currently the custodian of more than 8,000 of my dad’s slides (about half of them); I also have some from my mom, as well as roughly 1000 slides of my own that I took before I switched to digital photography. Most people don’t have slide projectors and screens any more, whereas we all have at least one device we can use to look at digital photos… so I have been thinking for a while that I might look through the slides, pick some out, and digitize them.

Options for Digitizing

There are several options for digitizing slides:

Buy a cheap slide scanner (many options under $100). I tried this with some slides last year for my high school reunion, and I wasn’t very happy with the results. The scan quality wasn’t great, and some parts of the photos were cut off, so I ended up returning the scanner that I bought.
Buy a more expensive scanner. I haven’t tried this yet, but I still could.
Use a decent scanner that is available at the public library. I did this with some of my dad’s slides a few years ago, but it is inconvenient and it’s not really feasible to do a large number of slides there.
Put together an inexpensive DIY (do-it-yourself) slide digitizer — this is what I decided to do. It works pretty well for my purposes, so I thought I would write up an article in case anyone else wants to try it.

Components Needed for Digitizing Slides

In order to digitize a slide, you need several components:

A light source to shine through the slides
Something to hold the slide and the camera steady so you can take a good picture of it
Something to mask out the light source around the transparent part of the slide (optional)
A digitizer (digital camera, phone camera, or scanner)

More details on each of these components are below.

Note: if you are planning to use your phone as the digitizer, and if its camera is near the center of the back of the phone, you might want to try the Kodak Mobile Film Scanner. It includes a light source and a support, and they have a free app that helps with cropping and turning negatives into positives. I haven’t tried it.

Light Source

For the light source, you want something that is uniform and a pure white color, so that the light illuminates the slide without changing the colors or adding shadows or bright spots. I opted to purchase an inexpensive 5″x7″ light box made by Rybozen, which can be powered by batteries or a cable that plugs into a standard USB-A port. I’m not an expert on light boxes, and this is a strictly amateur operation, but it had decent reviews and it seems to do the job well. As a bonus, you can use it (along with a magnifying glass) to look at the slides when you are picking out which ones you want to digitize.

Support and Mask

The idea of the camera support is to have something that fits around the slide and will hold the camera steady at its minimum focal distance. The camera I am using (see section below) will focus at a minimum distance of 2 inches, so I need a support that is 2 inches high and just over 2 inches square (because a standard 35mm slide has a cardboard frame that is 2 inches square).

I made the support and mask out of some card-stock-weight paper that I had in my closet, which happened to be a light cream color. It turned out to let about the right amount of light in to illuminate the cardboard part of the slide so you can read what’s written there, without causing a lot of glare on the transparent part.

For the support, I cut two strips that were each exactly 2 inches in height and roughly 9 inches wide. I marked them at 2 1/8 inch intervals along the width, and folded the two sheets together at each mark (see diagram and photo below). This made a square, which I taped so it wouldn’t come apart. I also tried making one out of a cereal box; this one was a little bit sturdier, but it didn’t illuminate the cardboard part of the slide as well, so I ended up preferring the cardstock, and it was sturdy enough to be stable with two sheets folded and taped together.

Diagram of cuts/folds to make the camera support

I used the same cardstock to make the mask: I cut out a roughly rectangular piece of it, and then cut a sort of rectangular hole in the middle (later expanded to be a square, see below). The exact dimensions don’t matter, and the hole doesn’t even have to be exactly rectangular or even have straight edges, as long as the light can completely illuminate the transparent part of the slide, and the cardboard part of the slide is bigger than the hole.

Diagram of cuts to make the mask (dimensions do not need to be exact)

End result: my set-up for digitizing slides

Digitizer

The options I had on hand for digitizing the slide were:

Panasonic Lumix DMC-TS6 digital camera — this is a compact, auto-focusing digital camera that I used to use a lot before I got my latest phone. It has a macro mode that can focus on objects that are 2 inches away from the lens, a 16 megapixel sensor, an optical zoom lens, and a setting for white balance.
Google Pixel 7a phone camera
A Brother printer-scanner-copier — this utterly failed to scan slides, even with the lightbox providing illumination.

As you can see from the photo at the top of this page, I ended up deciding that the Panasonic camera was the best choice for digitizing slides. I read the camera manual and played around with settings on the camera, and ended up with:

Program mode with Macro – Auto-Focus turned on. There’s one small spot in the center of the picture that the camera focuses on, so you need to make sure to point that to the middle of the slide.
Zoomed to as wide an angle as possible (this is what allows the macro lens to focus as close-in as possible)
Maximum photo resolution and image quality
White balance set to Daylight

Results

Here’s an example: a photo my dad took of a fire that burned down half of our school in Palouse, Washington, in April of 1976, when I was in fourth grade. I’ll show you what it looks like when digitized with both the camera and the phone.

Here’s what you get initially when you take a picture with the Google Pixel 7a. Using the mask seemed to confuse the camera and it wouldn’t focus on the slide, so I left it off. As you can see, the slide is not a very large portion of the field of view of the phone camera. (Note: this is not the full resolution — the photo has been scaled down for this web page.)

Here’s what you get initially when you take a picture with the Panasonic Lumix camera. One thing I like about this is that you can see the notes that my dad wrote on the cardboard part of the slide pretty clearly — the light color of the cardstock lets some light through the mask, which gets reflected back to the slide by the sides of the box support. When I used the darker cereal box cardboard as a support, it was much harder to read. Also, the slide is taking up a much larger portion of the field of view of the camera than it did on the phone, because the lens is so much closer to the slide. (Note: this is also not the full resolution — the photo has been scaled down for this web page.)

To see the difference in resolution of the photos, I cropped it down to one area of the photo (this is full resolution). As you can see, it is not super clear.

This is the same area of the photo from the camera — it’s bigger because there are more pixels in the slide portion of the field of view of the camera. Note how much sharper it is; you can also see the difference in the colors between the camera and the phone (the camera version is much closer to what the slide looks like on the light box than the phone version).

I’m pretty happy with the results, and I’m able to digitize a stack of slides fairly quickly once I’ve picked out which ones to do. I leave the mask on the lightbox, place the slide on the mask and make sure it’s fully illuminated, put the box around the outside of the slide, balance the camera on the box, check the framing, and click the button. This takes a few seconds per slide. For now I am not cropping the digital photos — I think it will be useful to have the writing from the slide included, and I can always crop individual photos down later if I want to.

I hope you found this article to be useful — happy digitizing!