dsd4

Use the Konica Minolta DiMAGE Scan Dual IV on a current Mac: macOS 11 and later, Apple silicon and Intel. No kernel extension.

Download Source

Raw DNG

Edit scans like camera raws. White balance, exposure and inversion stay adjustable in Lightroom, darktable or Negative Lab Pro, with the scanner's own colour calibration built in.

Multi-sampled and HDR scans keep extra tonal precision in dense areas, at the size of a 16-bit TIFF (88 MB a frame). Negatives can also be saved as ready-to-view positives that match the Minolta TIFF.

Colour profiles

Colours look right in any colour-managed app. Scans carry the original software's profiles: MLTF3200p.icc for slides, MLTF3200n.icc for negatives.

Multi-sampling

Cleaner scans from the same film. As in the original software, each line is read 2, 4 or 8 times and averaged: noise drops about 1.4×, 2× or 2.8×, and a single bad read is discarded. Crops also come out sharper. Scans take longer.

HDR

Recovers detail in the densest parts of the film: slide shadows and negative highlights. A second, brighter pass is merged with the first. In simulation, noise there drops about 4×, up to 2 more stops of usable range. Same file size; works with Minolta processing.

Negatives

Choose how negatives become positives:

  • Minolta processing: the original software's look, with its auto-exposure and film curves.
  • Simple invert: a neutral starting point, orange mask removed.
  • Raw: the untouched negative, for Negative Lab Pro.

Autofocus

Less waiting: focus takes about a third of the original's lens moves, and frames with an empty centre still focus. --af classic runs the original sequence.

Deblur

Rescues photos where the camera missed focus. The blur is measured across each frame; sharp frames are left alone, and grain and colour stay as they were.

Eyes in a portrait, soft from a missed focus
Original
The same eyes, deblur low
Low
The same eyes, deblur high
High
dsd4 scan --deblur low -o d.tiff
dsd4 deblur scan.dng --level high

Sharpen, denoise, 4000 dpi Experimental

Sharper, cleaner scans than the scanner alone delivers, based on Norman Koren's film-scanner MTF studies. Three options, on their own or together:

  • Sharpen: undoes the scanner's own measured blur. Grain is not sharpened.
  • Denoise: removes sensor and colour noise. Low keeps the grain; high also softens it.
  • 4000 dpi: sharpens and enlarges a 3200 dpi scan to 4000 dpi.
dsd4 scan --samples 2 --experimental sharpen,denoise-low -o x.tiff
dsd4 scan --experimental 4000dpi -o x.tiff

In the menu: Device & output settings → Experimental.

Razor-blade edgeMTF50
3200 dpi scan44.8 lp/mm
Resampled to 4000 by macOS35.3 lp/mm
--experimental 4000dpi53.8 lp/mm
Bicycle lettering, 3200 dpi
3200 dpi
The same lettering, sharpened
Sharpen
The same lettering at 4000 dpi, denoise low
4000 dpi, denoise low

It uses a typical Dual IV's measurements; calibrating yours gives the full correction:

dsd4 research mtf     # razor blade in a slide mount
dsd4 research grain   # frame with sky or blank film
dsd4 research noise   # blank film

Install

  1. Download the .pkg from the latest release and open it.
  2. Connect the scanner and insert a holder.
  3. Scan from Image Capture or Preview, or run dsd4 in Terminal.

Command line

dsd4
dsd4 scan --dpi 3200 -o s.tiff
dsd4 scan --film nega --minolta -o n.tiff
dsd4 scan --format dng --samples 4 -o r.dng
dsd4 scan --format dng --hdr -o h.dng
dsd4 scan-all --frames 4 -o roll
dsd4 --help