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Silverfast Multisampling revisited

but unfortunately little has changed…

in General Rants , Friday, October 09, 2009

UPDATE, July 8 2010

In the past month I’ve been using Silverfast multi-exposure almost every day, in a re-archiving project, and it has worked flawlessly.  I also have to admit that my sometimes harsh comments about Lasersoft I always regret later. Sometimes they can be infuriating, but often as not I suspect that it is mainly language issues. They’re actually a great bunch of people doing a great job of keeping film scanning alive for mere mortals who can’t afford Hasselblad’s luxury good price tags.  Oh, and my comments about excessive pricing ? I’m wrong.

So for the sake of consistency, I’ll leave this article up, but take it with a VERY large pinch of salt

Lasersoft’s Silverfast has long been considered the best scanning software around, although fans of Ed Hamrick’s VueScan would disagree. I’ve had a love/hate relationship with it for about a decade. I love the results it is able to deliver (once you’ve got over the learning curve) but I really dislike the user interface, and I have little time for the company itself, with its cranky staff and very exaggerated prices. I don’t believe I’m alone in this.On the positive side I have to recognise their continued support for a large range of scanners, many obsolete and/or orphaned by their makers. They play an important role in keeping film alive. I also realise that it must be getting harder and harder to maintain their business, especially sales of their higher range products such as Silverfast AI Studio. Which leads me to the point of this article, revisiting a topic discussed some time back.Around about version 6.0 Silverfast was pretty much complete. There wasn’t really much to add, which is a problem for a software company. Nevertheless things were added, often hyped to the heavens but actually delivering very little. For example, the “Studio” version of 6.5 added things with clever sounding acronyms (e.g AACO, Auto Adaptive Contrast Optimisation) which actually didn’t seem to do anything useful, although they spent a long time doing it. Ever desperate for upgrade revenue, a more recent attempt was Multi Exposure. As opposed to Auto Adaptive Contrast Optimisation, Multi Exposure is supposed to, er, optimise contrast, auto-adaptively. It does this by making two scans, the first at normal exposure, and the second deliberately over exposing to pull out shadow detail. It then combines the two into a final image. Initially I seem to recall there was an option to make 4 exposures, but this seems to have been quietly dropped.

Some film scanners, like my Minolta Scan Dual Pro, have the ability to multisample, taking a number (between 2 and 16 in the Minolta’s case) of samples at each point and averaging them out to improve the signal to noise ratio, especially in the shadows. Many Silverfast users were puzzled about the difference between “Multi Exposure” and “Multi Sampling”, especially as they are mutually exclusive in Silverfast, even for scanners like the Minolta where the film doesn’t move. An interesting discussion took place here. The drawback of Multi Sampling is that scan times are increased by the same factor as the sample count. Lasersoft promised that Multi Exposure would not only be faster, but would deliver better results.

Well, Multi Exposure went through a few iterations, and the 4x option vanished.  My experience is that it does not offer any significant dynamic range advantage over multi-sampling, at least as far as scanning slides is concerned. It is quicker, slightly faster than 4x multisampling. However, it has a serious flaw, which others have noted: the results are considerably softer than standard or multi-sampling. This may be due to misalignment, or due to flare or bloom in the over-exposed scan. The result can clearly be seen in the 100% crops below:


Top: 4x Multi Sampling - Bottom: Multi Exposure

Sometimes Multi Exposure works fine, but it is just too unreliable to use routinely. In most cases I find that 4x multisampling gives excellent results, with diminishing improvements (if any) at 8x and 16x. And in extreme cases, you can make two multisample scans and different exposures and blend them in Photoshop. So, in conclusion, another pointless feature.

I’ve said it before, and I’ll say it again: if Lasersoft really feel there is a future in this product, then they should concentrate on repackaging the technology in a completely new, modern user interface. Unfortunately, I would guess that the codebase is ancient, and I’ve never seen any evidence that Lasersoft have any interest in genuinely improving the Silverfast user experience. Since the competition is at best no better, and in general considerably worse, I suppose there’s little commercial incentive in doing anything.



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