The DCR file (.dcr)

Kodak's DCS (Digital Camera System) line was one of the first families of professional digital cameras. It started in 1991 with the DCS 100 and was built around Nikon and Canon film bodies, plus digital backs for medium-format cameras. DCR is the raw format of its later models: the DCS 720x and DCS 760 announced in 2001, the DCS Pro Back models, the full-frame DCS Pro 14n of 2002 and its successors, ending with the DCS Pro SLR/n and SLR/c of 2004.

A DCR file holds the sensor's readings as captured: one value per photosite (12 bits on the DCS Pro 14n), each under a red, green or blue filter (or no filter at all, on monochrome models such as the DCS 760M). Software has to demosaic them, apply white balance and a tone curve before there's a picture. Kodak's own software did that with the camera's settings; anything else uses its own rendering, so colours can differ from what photographers saw at the time.

The result for DCR files: Kodak's raw software, such as DCS Photo Desk, stopped being developed in the 2000s and was written for the operating systems of that time. Opening DCR files today depends on third-party software and on reverse engineering.

• LibRaw and tools built on it. LibRaw's camera list includes the DCS 520C to 760C and 760M models, the Pro Backs, the DCS Pro 14n and 14nx and the SLR/c and SLR/n. Tools built on it include the rawpy Python package, LibRaw's own sample tools and Microsoft's Raw Image Extension for Windows Photos.
• Adobe Camera Raw and Lightroom. Check Adobe's supported-camera list for your model.
• macOS Photos and Preview. Apple's current raw list includes only one Kodak camera, the DCS Pro SLR/n.
• RawTherapee and darktable read many older raw formats with their own decoders; test your own files.

For a collection of DCR files, the US National Archives recommends converting to DNG for preservation. Adobe's free DNG Converter does it for the cameras it knows; keep the originals as well. For a quick look, LibRaw's tools or rawpy can develop a DCR to TIFF or PNG:

# pip install rawpy imageio
import rawpy, imageio.v3 as iio

with rawpy.imread("100_0001.DCR") as raw:
    rgb = raw.postprocess(use_camera_wb=True, output_bps=16)
iio.imwrite("100_0001.tif", rgb)  # 16-bit TIFF

• The program doesn't know the camera. Raw support is per model. A tool may open Pro 14n files and refuse those of a Pro Back. Try a LibRaw-based tool: LibRaw's camera list covers most DCS models.
• It's a .tif that looks wrong. It may be a raw file from an earlier DCS camera, or a DCR renamed .tif. Ordinary TIFF viewers show garbage or a tiny preview. Open it in a raw developer, which reads the file's contents rather than trusting its extension.
• The colours look off. Third-party software doesn't know Kodak's processing settings. Set the white balance by hand from something neutral in the picture.
• Kodak's old software won't run. It was made for systems of the early 2000s. Use the tools above instead.

A good archive of old DCS work keeps the original DCR, a DNG copy, and a developed 16-bit TIFF or high-quality JPG for everyday use.

DCR files record the date and time, exposure and Kodak's processing settings, and often the camera's serial number. These cameras had no built-in GPS. Check with exiftool -a -G1 file.dcr before publishing a file. DCR contains no scripts; as with any old binary format, use maintained software to open files from unknown sources.