3D-Printed Slide Copy Attachment (DupliHood)

Started Aug 18, 2014 | Discussions thread
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ProfHankD Veteran Member • Posts: 6,689
3D-Printed Slide Copy Attachment (DupliHood)

Here's my really quick and easy 3D-printable copy attachment for digitizing 35mm or 6x6cm slides. I call it the DupliHood in honor of the old Spiratone Dupliscope that inspired it. My version doesn't include a lens, but screws into the filter thread of an appropriately close-focusing lens:

6x6cm DupliHood prototype on a Minolta Macro Rokkor 50mm f/3.5 and Sony A7

The parametric design for DupliHood is freely distributed as an OpenSCAD program and customizer application at Thingiverse, Thing 431624 , but details for design parameters and use are posted as an Instructable. You will need to tweak the parameters to make one appropriate for your camera and lens. It takes about $3 worth of PLA to print one.

How well does it work? Let's compare the same slide digitized by a 25-minute scan using a Nikon CoolScan 9000 (4000DPI for 80MP, 16-bit per color sample, multi-sample, RGB+NIR using VueScan) to the roughly 16MP active area of my HDR-mode JPEG from the A7:

The 80MP Nikon CoolScan 9000 scan

The 16MP (active area) copy via the A7 in 6.0 Ev HDR mode with DupliHood

The colors differ a bit, and maybe the Nikon scan is a touch more accurate, but both look better than the slide itself. You may have noticed that the DupliHood version looks a bit sharper despite the lower resolution. That's because it has higher local contrast (no, I didn't sharpen either image). In fact, let's compare 900x600 pixel 1:1 crops made from 80MP versions -- which required scaling the 16MP A7 image up to 80MP:

900x600 pixel 1:1 crop from 80MP scan using Nikon CoolScan 9000

900x600 pixel 1:1 crop from 80MP scale-up of 16MP copy using DupliHood on Sony A7

I don't think the DupliHood A7 image is missing much (anything?) that the Nikon scanner gets... and it would be even less likely to miss anything if I had used an A7R (24MP vs. 16MP active area for a 6x6cm scan). Obviously, the 35mm version of DupliHood would be even more competitive with the Nikon scan quality because it gets more pixels while the Nikon scanner gets fewer.

I'll still use my Nikon CoolScan 9000 when I need the absolute best quality -- it definitely has an edge in doing an NIR scan to help automatically remove dust, dirt, and scratches, and the VueScan software I use it with more reliably handles color restoration. However, the DupliHoodis an order of magnitude faster to use without suffering a major drop in image quality. If you don't own one of those nifty Nikon scanners that cost thousands of dollars when they were still available, I think you'll find my copy attachment is well worth the $3 of PLA it takes to 3D print one....

PS: I just noticed that the EXIF on the second crop incorrectly states it's from the Nikon. That's because I did the scaling and cropping by adding the A7 copy as a layer to the Nikon scan in gimp. The second crop really is from the A7 with DupliHood.

 ProfHankD's gear list:ProfHankD's gear list
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