SilverFast Ai Studio 6.5: Multi-Exposure Brings Out The Details
SilverFast Ai Studio 6.5 is a new version of the venerable scanning application. It now includes the ability to automatically detect the locations where content is placed on the scanner's glassplate, and more importantly, a Multi-Exposure feature that brings out detail in a photograph and increases the odds that your scanner's Dynamic Range will be used to its full potential.
Multi-Exposure aims at enhancing the Dynamic Range of scans from film material because a scanner rapidly reaches its limits with a single scan. Multi-Exposure only works with film material as it wouldn't add much value to reflective scans.
Film, such as Kodak's latest and renewed Portra range, has a very high Dynamic Range. Often, positive slides have a Dynamic Range of up to 8 f-stops, while negative film may go all the way up to 12 f-stops of contrast. The film is one part of the story, The scanner is the other. Some film scanners, such as Nikon's CoolScan LS-9000 have a potential of seeing contrast ratios that go 10,000:1.
As a first, the Epson Perfection V700, has a contrast range equally high, but for a fraction of the cost of a Nikon CoolScan. The only problem is to get those scanners to get into this range. With one exposure, the CoolScan LS-9000 will see a range of 3.18, while the V700 will go up to 3.09. These figures were found by LaserSoft Imaging, based on their own testing according to ISO 21550 standards.
With multi-exposure, the CoolScan LS-9000 will reach its maximum Dynamic ratio of 4. The V700 will do slightly worse at 3.91. The most important issue here is that SilverFast's Multi-Exposure feature will reveal all of the Dynamic Range these scanners are capable of.
Better detail in Shadow Areas
This in turn means more detail in the shadow areas and lower noise and grain in the result. Of course, when you are using a scanner that cannot capture a Dynamic Range that is high enough to reveal details in the shadow areas, Multi-Exposure won't help to bring them out.
However, LaserSoft tested the older Epson Perfection 4990, and found that one exposure resulted in a Dynamic Range being captured of 2.19. With Multi-Exposure set to 2, the Dynamic Range of this scanner improved to 3.38 - close to its maximum.
Not all scanners support multi-exposure. Epson's Perfection 4490, 4870 and upwards do, as do some of its Expression scanners. Nikon scanners are well represented in the list that you can find on the SilverFast web site.
Another new feature in version 6.5 of SilverFast is the one-click identification of image frames. The biggest stumble block to scanning a lot of photographs until now was dragging the frames around the photographs on the scanner glass plate. With Auto Frame, this tedious process has become much more efficient. I tested it with a couple of photographs randomly located on the glass plate and with the slides frame of the scanner.
The latter works but if you haven't filled up all the "slots", you end up with more frames than you need. For slides, the Auto Frame algorithm isn't perfect either. It cannot discern between the holes in the plastic that serve different purposes than holding the slide. Therefore, some adjustments are still necessary, but all in all, this feature is a real time saver.
Other SilverFast versions, such as HDR, have different new and improved features. We will be discussing those in the weeks to come.