How to identify slide/negative scanners that produce RAW files?

Question

I'm looking for a 35mm slide and negative scanner that can give me raw files like my camera does.

I have a ancient Polaroid SprintScan 35, and it's frustrating to use. Back then, there weren't raw files, so all the processing had to be done in the scanner, and you were stuck with whatever annoying clickety-click and dumbed down software interface the manufacturer dreamed up. This scanner is now dying.

Meanwhile here in 2016 I have software that handles raw files from my Nikon camera in a way I like. I've been trying to find a simple scanner that can give me raw files, but can't seem to find a search strategy that yields useful results. I've tried various ways of subsetting the list of scanners at NewEgg and Amazon, but I haven't found any that mention that they can produce raw files. Since the descriptions don't mention it, I haven't found a way to search for it.

What's the magic incantation to get a list of scanners that can export raw files?

Most companies tell you how wonderful the bundled software with their scanner is, but in dumbed down patronizing terms. The few that I have used I've found to be very annoying since you never know what it's really doing, and everything is a one-off manual clickety-click operation.

A good example of the equivalent in a flatbed scanner is a Canon LiDE 120. It comes with the obligatory annoying software, but that software can be set up to grab a raw file and then pass the file name on a command line to a program of your choosing. I can ignore all their fluff, and even have my software automatically launched after each scan.

The above would be great, but even just dumping a raw file to disk would be acceptable.

What do I search for or how otherwise do I find such a product?

Answer 1

I scan negatives and slides to create RAW files. It is largely a matter of scanner resolution limits and software. I use an Epson V700 which has a transparency scanner, film holders and a selection of software. It also can scan natively to 6400 pixels per inch.

The software I use is Silverfast and Vuescan. Scanning film at sufficient resolution can be a slow process and sometimes the use of software such as digital ICE will make for large and slowly acquired files. The majority of my scans are old 4 x 5 inch transparencies so the magnification is quite small and I rarely scan above a resolution of 2400 pixels per inch. 35mm slides would need a higher resolution and take much longer to scan.

Look for any scanner that can scan transparencies and includes some good quality software. Vuescan is a one man operation but is cheap and capable software. A good tutorial on scanning should assist you to get going. Scanned slides will not be as easy to work with as RAW digital image files. There are likely to be many more variables to adjust before creating useable RAW files.

Answer 2

It's tricky to compare RAW file formats from digital cameras and film scanners. They're quite different.

A raw file from a digital camera contains the 'unprocessed' sensor data along with a set of metadata. These allow proper decoding of the raw data. Typical example is information on how to perform demosaicing of the raw sensor data (most digital photo camera sensors have color filters applied in a well-defined pattern on the sensor pixels - the filter recipe is required to properly decipher the sensor data).

For film scanners, there's no demosaicing to perform, as the scanner will yield the 3 channel values (or 4 if there's also an infrared channel) at once for each pixel. Typically the 'raw' output of a film scanner is a linearized RGB file.

The processing workflow will also differ between processing a digital raw file and a scanner raw file, in particular when processing older film types due to color shifting over time, and due to more substantial digital cleansing of scanned film negatives (due to scratches, dust, dirt and mold stains on the film and emulsion).

The option to store scans in a 'raw' format depends mainly on the scanner software in use. Also, often a scanner performs some image processing prior to generating the 'raw' file (e.g., reducing dirt and dust by processing the infrared channel and by exporting only R, G and B channels).

Answer 3

The OP asked for a 35mm scanner. Depending on the quantity of originals to scan, a dedicated 35mm scanner may prove faster (in relative terms). I have a Canon 35mm scanner and an Epson V600. Both use either Silverfast or Vuescan. I can understand the RAW requirement, but for all intent and purposes a TIFF file will do as well. Color slides and negatives are always a challenge, as their color temperature may be off because of aging. One may need to use different recipes/settings based on the source of the scans to achieve optimum results.

Answer 4

You can do a raw scan with any scanner supported by Vuescan. The Professional Edition will allow you to save an un-color-corrected, linear scan at 16bit per channel (plus the infrared pass as alpha if the scanner is capable of such a thing).

See: https://www.hamrick.com/vuescan/html/vuesc33.htm#outputrawfile