ScanCafe1) uses a Nikon Super CoolScan slide/negative scanner for slides and negatives. Choose the following options:
If you don't choose ScanCafe, choose a service that:
For slides, a DSLR adapter like the Nikon ES-1 (about $45 from eBay) seems to do a good job. You will need a 24-megapixel DSLR to get all the detail, a macro lens such as 100mm, an off-camera flash to aim at the diffuser, and possibly one or more extension tubes to capture a whole frame at a time.
Here's a real-world, effective resolution comparison between scanners5):
| Model | Type | Resolution (DPI) | 35mm Resolution (MP) | 110 Resolution (MP) |
|---|---|---|---|---|
| Pacific Image PrimeFilm XA6) / Reflecta RPS 10M | Film | 4300 | 25 | 6.3 |
| Pacific Image PrimeFilm XE / Reflecta ProScan 10T | Film | 4100 | 23 | 5.8 |
| Nikon CoolScan V ED | Film | 3900 | 20 | 5.2 |
| Nikon CoolScan 5000 ED | Film | 3900 | 20 | 5.2 |
| Nikon CoolScan 9000 ED | Film | 3900 | 20 | 5.2 |
| Plustek OpticFilm 8200i | Film | 3250 | 14 | 3.6 |
| Epson Perfection v800 Photo | Flatbed | 2300 | 7.1 | 1.8 |
| Canon CanoScan 9000F Mk II | Flatbed | 1700 | 3.9 | 1.0 |
| Epson Perfection V600 Photo | Flatbed | 1560 | 3.3 | 0.8 |
Flatbed scanners are great for prints but not for slides or negatives.
For your very best photos and if money is no object, consider drum scanning7). But the cost is dozens to hundreds of dollars per scan.