About two to three years ago I bought a new scanner at Staples, one that had an attachment for doing transparencies or slides and negatives. For those of you too young to remember, transparencies, or commonly called slides, were a type of still picture beamed onto a screen with an overhead projector for viewing. These were very common in the mid-to-late 20th century before digital photography.
My father loved using the slide format because he was able to share his travel photos with a larger audience at once, rather than have them gathered around a scrap book. With an overhead projector he could make a presentation and reminisce about his travels to an interested group. He even converted many photographs to slides that he had taken before switching to the transparency format all together.
When he died, I inherited the family photograph collection including about 2 dozen reels of slides or more. I haven't counted lately. My siblings and I wanted to digitize this collection, but the quoted price was beyond what we wanted to pay. So I dusted off the attachment to my scanner to see what it would do. I had never looked at the attachment when I first bought it, but now I realized that the attachment only did 4 slides at a time. FOUR slides! According to my calculations I had about 3000 slides. Scanning 4 slides a day would take me about 2 years to finish.
So I started in, 4 slides at a time. I have been doing more than 4 a day. I started at the beginning of this year and am already about half way through.
I have learned that the attachment has a limited space in which to scan the slide and some slides are larger than the allotted space. To compensate for that I have had to scan some slides more than once in order to get the full picture. These duplicate scans will then have to be pieced together in a photo editing software to make one large photo. I haven't done that yet. Many times, just turning the slide 90 degrees in the attachment will be sufficient to get a decent scan in one picture.
I scan my slides in TIF format. TIF is a stable format that does not lose detail with each opening of the photo. It takes longer to scan in TIF than it does in jpg, but the stability is worth the few extra seconds.
My scanner is an old one, no longer being made - an Epson V200. I think it cost me about $90 or less. I remember it was on sale. It has served well and has been easy to use. If it continues to serve well up until I just get all my slides scanned it will have been worth the money. The quoted price to us for scanning the slides by a "professional" was, I think, about $1 per slide.