Raw Scanning on Hasselblad Flextight X5
This service provides access to the full scan quality of the Flextight X5 scanner.
The image is digitized and coded without loss of information, in full color depth and according to the resolution selected during the order. The color profile provided is completely linear and neutral of any correction. Each image thus encoded represents the exact digital version of the photograph lying on the film, in all its details, hence the term "raw scan". It should be noted that negative films produce digital images that are also negative.
A "raw scan" digital image is not a final render, such an image can not be used as is for the exchange, display or pinting. Post-processing work must be undertaken to correct the actual color profile of the film. This post-processing work can be added as an option to the ordering of a raw scanning service. Presenting this post-processing work as an option allows, when this one is not included in the order, to offer the most economical as possible scanning service for our demanding professional clients, experienced in image editing tools, or more generally to any perfectionist customer.
Supported film and image formats
Flextight X5 scanners use the principle of the virtual cylindrical drum. This principle makes it possible to format the linear region of the film being scanned while avoiding bringing it into contact with a transparent medium. To hold the film strip in position, it is inserted into a flexible support having an opening corresponding to the useful dimensions of the area to be digitized. Only the "out of scope" edges of the film are in contact with the flexible media. This involves the use of a collection of flexible media, each adapted to a type of film and a particular image size. All standard image formats are supported for 135, 120/220 photographic film strips as well as for large formats with an image width of 4 inches or 90 mm.
Resolution on film
The definition of the CCD linear imager of the scanner is 8000 triplets of primary photosites. It is exploited as much as possible for each width of photographic film. The maximum resolution being obtained when the image lying on the film is scanned in its small width, this is the scanning mode retained by default when possible. However, given the slight variations in the size of the images on the films and a slight overlap of the flexible supports on the useful area, it is necessary to crop more or less the image. In fine, the scanning width must always be slightly greater than the theoretical nominal width of the image. On the other hand, to standardize the choice of scanning resolutions on the film, we have set the following values:
- 8000 dpi and 5000 dpi for 135 films (24x36 or XPAN shots)
- 4400 dpi and 3200 dpi for 60x45mm shots on 120/220 films
- 3200 dpi for higher-dimensional pictures on 120/220 films
- 2200 dpi for 90mm wide-format shots on large format films
- 2000 dpi for 4-inch wide-format shots on large format films
Note that in the particular case of 135 format films, the standard settings can lead to an extreme resolution of 8000dpi. However, given the average grain size of the dyes making up the most common emulsions, this value is generally excessive. A resolution lowered to 5000dpi is therefore also proposed as standard for these film formats. This value also reduces the cost of scanning in this case. In the case of 120/220 films with an image size of 60x45mm, we can also offer two resolutions as standard.
Also note that the "raw scan" images encoded in a native file in hasselblad raw-3f format always carry all the pixels generated for each "line" of the scanned film (full scan width, 8000 pixel lines). Unusual pixels located in the black lateral areas that are outside the region of interest (out of the useful area of the image) are present, regardless of whether a crop has been set or not in the raw-file settings. In the particular case of the scanning of 135 films at a resolution reduced to 5000 dpi, these black lateral zones are quite important. A raw scan file delivered in native Hasselblad raw-3f format is therefore always larger than an output file delivered in TIFF format, whether it is post-processed or not, since this last file format only carries the cropped content of the image.
Types of emulsions
All emulsions are accepted, colour, black and white, negative and reversal. Note that the unit rates of the service "raw scanning" are decreasing with the quantity ordered and are independent of the type of emulsion. Technically speaking they only depend on the film format, the useful size of the image and the desired scanning resolution. So that for a given technical combination, it is possible to obtain the best quantitative price for different emulsions.
To be compatible with the flexible film holders of the scanners, the films must be conditioned in the form of pre-cut strips that can contain from 1 to 6 images, depending on the type of film. Note that in the vast majority of cases, photographic films are already conditioned this way after development. If necessary, we cut the tapes that are delivered to us to adapt them to our flexible supports. Only 24x36 slides can and should be mounted under standard 50x50mm cache, the thickness of which should not exceed 3mm.
Before scanning, each strip of film is subjected to ventilation of filtered and ionized air. Some rare spots of dust can nevertheless subsist. If so, you will need a digital editing session to perfect the result. On the other hand, scratches, stains and cracks can not be removed by physical dusting. Given the exceptional optical sharpness of Flextight X5 scanners, the slightest defect of preservation of the film, even invisible to the naked eye, will be revealed. Therefore, special attention should be paid to the handling of film strips to avoid any fingerprints.
For each scanned image, the format of the deliverable file is selectable from two possible choices:
- either the native Hasselblad raw-3f format
- or the TIFF-6.0 format
Regardless of the file format chosen, the encoding of the image is done in full color depth (16-bits per color channel).
The destination color space is sRGB IEC61966-2.1
For each image, the Hasselblad raw-3f file is generated under FlexColor. It obviously encapsulates the "raw scan" image in full quality as well as a 3f record corresponding to a linear and neutral profile. The color depth is 16-bits per color channel. The "raw scan" image thus provided is the faithful digital version of the image coated on the film, no noise correction or enhancement is included, not even cropping. The "TIFF" counterpart of the "raw scan" image, with linear and neutral profile, is generated under FlexColor by an export operation of the Hasselblad raw 3f native file to which digital image cropping is applied.
The data fields labeled "Legend", "Signature", "Copyright" and "Keywords" of Hasselblad raw-3f files can be edited with the FlexColor software and transmitted (encapsulated) in the exported TIFF files. Having TIFF files, it is obviously possible to enrich these metadata using other image editing tools. In our raw scanning offer, these metadata fields are left empty by default.
About Hasselblad FlexColor Software
This software, freely downloadable from Hasselblad technical support, performs two major functions:
- control of a Flextight X5 scanner in real time, ie when this device is connected to it.
- Delayed retouching of raw scan images previously generated in Hasselblad raw-3f format.
The Hasselblad raw-3f file format is a variant of the TIFF standard with encoding of the main image without data compression and maintaining the full color depth. The main difference with the basic TIFF-6.0 standard is its ability to encapsulate the user-managed post-processing workflow history under FlexColor while keeping the scanned raw image intact. In return, the direct editing of images encoded in this file format can only be performed by the FlexColor software. In Photoshop it is also possible to import such Hasselblad raw 3f files, for editing in the native format of Photoshop. This import requires the installation of a plugin for photoshop, provided free of charge by Hasselblad.