If you have a dSLR, you can probably use a 'T' adapter to attach a bellows unit with an old enlarger lens to it. If you backlight your slides with a 5500K, 93 CRI CFL light source (Alzo sells good ones) bounced off a white card, you can copy them 1:1 with such a contraption. You just need a copy stand or similar contraption to keep everything lined up.

Do a CUSTOM white balance of the light. Use MANUAL exposure — Once established, it is the same for every slide. Shoot raw, if you want latitude to play around in post production.

Using a slide copier setup on your camera will give you better images than all but the very best high end scanners. It also works one heck of a lot faster!

Early on I got a document scanner that included a slide adaptor. The scanner did an ok job with paper and scanning prints but when it came to doing slides it really sucked. I tried a few other offerings that were equally abysmal. I had about 25,000 slides to scan and I wasn't going to start that process until I finally had a technology that worked effectively.

This eventually led me to the Nikon scanners. Their middle model, the Super Coolscan 5000ED which is no longer available was expensive like hell but did superlative work. It also allowed me to load a batch of slides for scanning so that I didn't have to constantly feed individual slides.

Much later I also bought an Epson V750 Pro scanner. This was a flat bed instead of a film scanner but it too was designed for slides and 35mm film. What was really nice was that it also did negatives of different sizes, something I realized later I had needed too. The only down side of this scanner was that you couldn't do batch scanning. They did have a holder for a dozen or so slides but you had to place them into the frame and then dig them out later and you had to then separate each image in the scanned result. That is a pain if you have lots of slides to do.

Between these two machines all my scanning problems went away. I had control over my scanning quality and my film collections eventually went digital.

I went this route due to volume. There are a lot of services that will do the scanning for you for a price and if you're only doing a few hundred slides or negatives it's cheaper to use the services. But if you have a lot to scan it ends up a lot cheaper using the scanners instead.

Before and after acquiring these two machines I've seen other offerings for the consumer. From what I could tell most of them were toys. They would do a scan and some rather easily, but the quality always sucked. They lack the sophisticated software too and many have low resolution.

That's not to say there aren't other good scanners but make sure you go through reviews before you take a chance on one of them.

I should also add that both scanners have a driver that looks like an airplane cockpit. The Epson however, to its credit, has three views. One is fully automatic and simple, then there is one that gives you some control and it's mostly in English, and the third view is the airplane cockpit for total control. I rather like that design too.