My father bought a scanner with a fitting for scanning slides on, dependent on the amount of slides it may be worth while buying one.
That was what I tried - not impressed despite high res scan. I also tried one of these £40 dedicated slide scanners that they sell in Maplin and sometimes Lidl / Aldi. Even worse. Back a few years I had access to a Nikon professional 35mm scanner - now THAT was a different story (and a mere £1.5K price tag 15+ years ago)
It is a bit of a bugger setting up the old projector & screen and then a digicam on a tripod to eliminate hand shake but that was by far the best option