For a long time, SilverFast Ai Studio and HDR Studio, LaserSoft Imaging's scanner and image digitisation software, have been capable of generating High Dynamic Range images from ordinary slides and negatives. And it also had the capability to remove dust, scratches and speckles without using a scanner's built-in ICE feature (prohibitively slow!), but the two technologies have only recently been optimised to near-perfection.
The result is that photographers but also museums and libraries, can now archive their analogue images using little more than an inexpensive scanner and the SilverFast Archive Suite.
Users of prosumer and professional dSLR cameras can choose to save their images in the camera’s internal “RAW” format, a file format which has been called the equivalent of an analogue photo negative. Camera RAW as it is called has many benefits: you can generate multiple creative versions of it in software like Apple’s Aperture or Adobe’s Lightroom, and you can convert RAW files to very large resolution TIFFs without noticeable quality loss—e.g. a 300 dpi A2 print can be generated off a 12 megapixel Camera RAW file, depending on the resolution of the lens used to shoot the image.
Doing the same with a scanned photo from a film negative or a colour slide has been challenging to say the least. Scanner software was not capable to use the analogue medium’s full dynamic range (flatbed scanners often have an optical density of only 3.0 Dmax, whereas to include the complete dynamic range of a negative or slide, you need at least 4.0 Dmax), dust could be removed using a technology that only was present on more expensive scanners (ICE) and which took forever to finish, and the resulting image often had some automatic software correction applied to it which rendered the result useless for archival purposes.
SilverFast Ai Studio and HDR Studio have been capable of generating a negative or slide’s full dynamic range for some time now using a technique called multi-exposure (something VueScan apparently can do as well), and dust could be removed using the scanner’s built-in infrared capacities (called “iSRD” using the same infrared channel used by the ICE technology, but about ten times faster) but always only when you were working with the SilverFast application. The HDR images SilverFast Ai Studio could generate did not include the infrared channel and therefore were not really the equivalent of a Camera RAW file in that the scanner HDR file did not contain all the image information necessary to create perfect and multiple versions off it.
In LaserSoft Imaging’s latest version of SilverFast Ai however, you can create a 64-bit HDRi file, which is a HDR file (16 bits per colour channel in RGB) with the infrared channel added to it (another 16 bits, resulting in a 64-bit file). Such a file can be handed off to SilverFast HDR Studio for an automatic and optimised workflow in which dust, scratches and speckles are removed automatically, and the file saved as an HDR file without dust or a JPEG 2000, or TIFF file.
As SilverFast’s HDRi file format is a huge TIFF file, you can also further edit it in Photoshop CS4 Extended if you wish, although staying within the SilverFast Archive Suite has two added benefits: the first being a potentially automatic workflow for multiple images (batch processing), the other the automatic dust and scratches removal based on the infrared channel information in the file.
The combination SilverFast Ai Studio/HDR Studio is therefore packaged by LaserSoft Imaging as an Archive Suite—a bundle of software to archive negatives and slides (and to scan positives as well, of course). The image information that comes out of this SilverFast Archive Suite is perfect RAW data from scanned negatives and slides and it’s only available for specific scanners. One of the most popular scanners in the list of supported devices is the Epson Perfection V700 series, of which I still have the original model in my possession.
Both the V700 and V750-M Pro are capable of all the technical tricks that LaserSoft Imaging applies to get a perfect 64-bit RAW image as a result. The V750-M Pro has the added benefit of fluid support for slides and negatives, but scanning with fluids is messy and it only helps to further decrease scratches and dust.
The latest version of SilverFast (6.6.1) can capture the HDRi information not only into a 64-bit colour file but also in a 32-bit grayscale HDRi file. For only some 100 Euros more than the Ai Studio version LaserSoft Imaging lets you now have this new Archive Suite. I therefore wholeheartedly recommend you try out the demo that can be downloaded from their web site and see for yourself.
