4-Mar-2023

I just found a box of old 35 mm slides and photo negatives in my mother's house. Now I would like to preserve them by scanning them and making them available for the family online in Flickr and Google Photos.

In the '90s I owned a dedicated slide/film scanner by HP. I photographed a lot and just paying for the development of the film and then scanning straight from negatives or slides was the cheapest way to get high-quality digital photos. Eventually, I switched to digital cameras and scanned all my old slides and not creating any new ones and no longer had a need for such a scanner - so I sold it. Now, 20 years later, I need a new solution.

If you need professional, high-quality scans, you should probably use a scanning service that can scan your images using a drum scanner. They are expensive but produce astonishing results. Obviously, this is not what I need for a box of family photos from the '60s.

The second-best option is a dedicated slide scanner, the kind that I had. They work a bit like a flatbed scanner but instead of being optimized for large A4 documents (or the equivalent US variation) they are optimized for a tiny slide or negative. Such scanners produce a sharp, high-resolution image with good dynamic range.

My first thought was that decent quality slide scanners should not be expensive today as technology has progressed - but then I realized that since there is little demand for such, no one really makes them anymore. Agfa, Canon and Minolta all used to make slide scanners but they haven't for 20 years. Even old second hand scanners are hard to find as they are over 20 years old and most need SCSI. One of the last new such scanners was the Minolta Dimage Scan Elite 5400 which was released 20 years ago in 2003. The latest Windows software was for Windows 7 - but it does come with USB. But even such an old used scanner is often around €500. Too much for my case.

In general, if you try to use an old high-quality scanner today then software support might be a limiting factor. In such cases, you should check out VueScan by Ed Hamrick. It supports a number of scanners directly making it possible to use many scanners you no longer can find a driver for. VueScan communicates directly with the hardware without the need for a manufacturer provided driver.

There is one manufacturer that still makes proper slide scanners and that is Plustek with their Opticfilm range of scanners. But even the cheapest model starts at about €300.

Flatbed scanners also used to come with a backlit top to allow for scanning transparent objects such as slides but often with a resolution a bit too low for such a small image when scanning 24 x 36 mm slides/film. Some former high-end models might however, be a good option if found secondhand for a good price.

If you search on Amazon or similar sites you may find a number of slide scanners for around €75-150 by "brands" such as Dgodrt, Mersoco and Ashata. These devices are not really scanners but low-quality digital cameras in plastic casing with a backlight and SD card slot. When you press a button, the built in camera photographs the entire slide at once and stores it on an SD card. This method could produce good results if made with quality components but that is usually not the case. Especially the resolution and dynamic range leaves a lot to be desired. However, if all you need is "draft quality" to be able to take a quick look at photos or browse among them to select some for higher quality scanning, then this solution might be enough.

There is, however, one cheaper alternative that might produce equal or better quality. There are several companies that make simple mechanical devices consisting of two plates. The lower one has a backlit white square the size of a slide and the top one, about 80 mm above has a hole in it. You place the slide on the backlit white square and your smartphone on the top plate with the camera peeking through the hole. This way your smartphone camera will be perfectly flat in relation to the slide and allow you to photograph the slide.

The idea is simpel and you can certainly produce draft quality copies of your slides/negatives this way but there are a number of problems. And many of them could be mitigated with proper software.

One of these devices is a Danish product called Picto Scanner, trendily spelled in all lowercase. The same product is also sold with a Kodak logo on it for those who thinks that makes a difference. This variation is called the Kodak Mobile Film Scanner. The product is mostly made of cardboard with a plastic diffuser with some LED lights under it and a plastic holder for the slide frame or negative. The advertisement said "Danish Design" which might explain the logic of putting the backlight on/off switch conveniently underneath the device where you only can reach it by turning over the device and causing your phone to slide off.

There are two major problems with this hardware design.

1. Many new smartphones cannot focus properly at such close range. With the Picto Scanner the focusing distance is about 85mm and for example the newest iPhones and the OnePlus 10 Pro that I use are examples of phones that cannot focus at that distance. Fortunately, I only needed to elevate my phone an additional 10mm by putting some rubber standoffs underneath the phone to make it work.

2. Even at this close distance, a 24 x 36 mm slide will only make up a tiny portion of the area that the camera sees. This means that most of the picture has to be cropped away, resulting in a low-resolution image.

A full frame photo with my smart phone results in a 4000 x 3000 pixel image. Using the picto scanner the slide makes up less than 1/3 of the width and height of the image, resulting in a surface that is about 10% of the entire frame. The resolution ends up being about 1000 x 800 pixels.

Yes, you can zoom in, but that is just digital zoom and results in the 1000 x 800 image to take up 4000 x 3000 pixels with no more detail than the 1000 x 800 image. Actually, the OnePlus does use a 48 MP camera sensor with pixel binding to produce the 4000 x 3000 so the actual result might be as good as about 2000 x 1600. It's complicated. However, you can NOT use the tele-lens for optical zoom since that lense is unable to focus on short distances. 

The result is not great but it is just enough to show to relatives on-line. And it is much better than just having the slides in a box in a closet.

Unfortunately the Picto Scanner / Kodak Mobile Film Scanner comes with Android / iPhone software that is very disappointing. There is one slide for color correction and a button for taking an image but that is it. The software doesn't even crop the image automatically. You are probably better of using the phone's built in camera app - especially if it has a "manual" or "pro" mode where you can adjust some things manually.

That is another problem, your phone thinking that it is seeing a live scenario when you try to photograph a slide - causing the phone to try to make on-the-fly corrections and adjustments. Typically, you get the best result if you lock the ISO setting to 100 or whatever your lowest option is, lock the focus to prevent auto-focus movement and lock White Balance at 6500K. Then you can adjust the shutter speed to get a suitable exposure level to compensate for any dark or over exposed originals - and with 1960s amateur slides there is going to be a lot of that.

And make sure you use a shutter delay because this cardboard device does cause the phone to wobble even at a slight touch of the screen.

UPDATE 23.3.2022

I found a second hand Epson Perfection V370 flatbed scanner for not more than the Picto Scanner device cost me. The V370 can scan 35mm slides/film at an impressive 4800 DPI, resulting in images that are about 6500 x 4200 pixels (± 100). The Epson software will auto-crop the images, resulting in slight variations in image size, especially between frame mounted slides and non-mounted film strips. The results are significantly better in every aspect compared to the Picto Scanner - but it is slower and a bit bulky.