Here's a simple little (ok, it is biggish) slide copy adapter that fits into the filter screw thread of a close-focusing lens so you can quickly make high-quality digital copies of 35mm or 6x6cm slides using your digital camera. It's a customizer app because you will almost certainly need to tweak the design parameters for your lens.
See my Instructable, http://www.instructables.com/id/3D-Printed-Slide-Copy-Attachment/ , for details.
There is now a third version posted here, 20161022, changed to accommodate a new bug in MakerBot's Customizer. The second version, 20140824, which has a few improvements including a quick part to print so you can check fit and alignment of the screw thread, and the original 20140817 version, are both still here... but renamed so customizer doesn't grab them.
This is a very straightforward print. You'll want to make the tube using opaque black filament. The spring film holder should be made of a neutral color to avoid imposing a color cast; I used white. If you decide to try printing the diffuser, use white or clear filament -- but it is not necessary, and you might get more even lighting using a diffuse light source. I printed everything in PLA using 0.25mm extrusion and 25% fill. It uses well under 100 grams of material in total and prints quickly on my MakerGear M2.
The photos of Copenhagen are a scan that took 25 minutes using a Nikon CoolScan 9000 and the same slide photographed using a DupliHood on a Sony A7. Despite 80MP vs. 16MP active image area resolutions, the 80MP-equivalent 1:1 crops show the DupliHood image isn't clearly inferior. Three more DupliHood copies of 1965 slides taken by my uncle Gordon (dust removed using gimp) show excellent quality. This really can work quite well.
There are some issues in tweaking the design for your lens and in using the DupliHood -- see my Instructable, http://www.instructables.com/id/3D-Printed-Slide-Copy-Attachment/ , for details.