In reply to Eeyore:
I've no doubt everyone will have different opinions on this and folk will hopefully chip in with their ideas. There are a number of folk, quite often professionals, who have successfully used digital cameras for quite high quality slide scanning and if you search on tinternet, you'll find them soon enough. There's plenty out there to give you a good idea of how to go about it. I suspect the era of dedicted slide scanners has now been overtaken by cheap technology.
Anyhow, for what it's worth, what I have personally found to work quite well is the following:
If you can find one, a classic lightbox provides a fast way of both checking large numbers of slides (using a loupe) and also for then 'scanning' using a modern digital camera.
I've found that a camera that has around 12Mp resolution or higher, when used with a decent macro lens (or at least a lens that allows reasonably close focus, so that you can get the 35mm slide to fill at least around 25-30% of the frame which you can crop later) produces pretty good results - certainly comparable to, if not better than, a high end old-school slide scanner.
The advantages are manifold: it takes seconds to get a 'scan', compared to ages with a slide scanner, and you can bracket and muck around with white balance, aperture etc if you want, although I've found the auto white balance on modern cameras and between around f5.6-8 seems to get it spot on most of the time with a light box.
My set-up comprises an old Jessops lightbox, a Canon EOS-M mirrorless camera (available for under £150 these days) mounted on a tripod with a 11-22mm zoom lens. I use a cardboard tube with black interior (cut from an old whisky bottle) to act as a 'blind' to keep extraneous light out, plus a dark card mask over the slide on the box to make sure the light source is only shining through the film emulsion.
You put the slide on the lightbox, get the camera set up so it's square-on to the slide, with the lens inside the light-excluding tube and position the camera so that it's at its closest focus distance. With the Canon 11-22mm lens, because it's not a macro, it can't get close enough to fill the frame, only perhaps about 30%, but even so I've found that the EOS 18Mp sensor captures plenty of detail so that when the image is cropped, it's still got pretty decent resolution. The other advantage of the EOS is that it's got a touch screen you can use for focus and delayed shutter, so that you can take multiple exposures of a slide easily with different exposures simply by pointing at different bites of the slide - makes it very quick and easy to experiment to get the image you want.
I've also used a Sony Nex 6 with a Nikon Macro lens attached to produce similarly good results, so I think any modern camera with high-res sensor and decent glass will probably do the trick. If you've got a DSLR or full-frame, I imagine the resolution and image qulity would surpass most dedicated slide scanners these days.
I did a test with a slide that had been drum scanned 5 years ago for a magazine and the EOS scan was just as highly resolved. The colours also came out better! So that convinced me. One of my EOS 'scans' has since appeared on the front cover (A4) of a magazine - it looked pretty sharp and the colours came out great.
Don't forget you'll need a remote way of triggering the shot as well, either the touch screen delay available on some cameras, (or Sony have an app to trigger their shutters by waving your hand over the eyepiece) or an infrared remote release.
Some examples of slides scanned in this way are here:
https://www.flickr.com/photos/36689155@N02/25066750646/in/dateposted-public...
https://www.flickr.com/photos/36689155@N02/24257005541/in/dateposted-public...
https://www.flickr.com/photos/36689155@N02/23687296704/in/dateposted-public...
https://www.flickr.com/photos/36689155@N02/24209945056/in/dateposted-public...
https://www.flickr.com/photos/36689155@N02/24231754665/in/dateposted-public...
https://www.flickr.com/photos/36689155@N02/24205671636/in/dateposted-public...
https://www.flickr.com/photos/36689155@N02/17285258394/in/dateposted-public...
https://www.flickr.com/photos/36689155@N02/16197503777/in/album-72157650104...
Alternatively, if you want a very quick way of 'batch scanning' large numbers of slides at reasonable quality without having to spend much time at all, and you have a slide projector and a DSLR with Macro lens, I can recommend the following method which really does work:
The quality isn't as good as the method I descibed earlier, but it's not bad and you can shift a carousel full of slides into digital in minutes. If it's just family snapshot type stuff, this is a pretty good way to digitise in bulk.
Hope this provides a few ideas,
Col