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Wet mount scanning

squeezing the last drop out

in Film , Wednesday, February 16, 2011

Back in October, a blog post by Ctein on The Online Photographer first alerted me to existence of 3rd party fluid mounting kits for many scanners.  Specifically, he mentioned ScanScience‘s kits, based on their Lumina fluid.

I was intrigued enough to check this out, and eventually ordered a kit usable on my Minolta Dimage Scan MultiPro from ScanScience. Since they are in Canada, and the fluid cannot be carried by air, it takes quite a while to arrive, and it’s also better to order a reasonably generous supply.  So there’s quite an element of flying blind here, but my feeling was, well Ctein knows what he’s talking about, what the hell.

Anyway, it arrived a few days ago, and I started playing around with it. Precision scanning is both fiddly and something of a black art. My initial impression of fluid mounting is that it certainly increases fiddlyness, and also adds several more ways in which you can screw up a scan ... or indeed a scanner, in the worst case scenario.

My initial attempts were not too successful, and I had to dismantle a 6x9 glassless holder to fit the fluid mount assembly as recommended. But after a few tries I started to get the hang of it. The main challenges are getting the right amount of fluid onto the various surfaces, and avoiding dust and dirt contamination.

The basic idea with fluid mounting is to keep the film flat, and to avoid optical path degradation which arises from various factors in dry scanning - I won’t repeat the explanations here, you can find them at ScanScience and various other resources.

The following images show the best result I’ve obtained so far. Comparing a couple of sections of a 4800dpi XPan scan of Ektachrome E100G, wet mounted and dry mounted, shows some advantage, at 100% magnification, for wet mounting.



At the top you can see the wet mount version on the left, dry mount on the right [CORRECTED!]. Colour differences are down to slightly different settings in Silverfast HDR - ignore these. The images have suffered a little in JPG compression, but looking at the rightmost telegraph post, and the background forest, you can see a touch more resolution. But it’s not exactly jaw-dropping.

The next example is a bit more convincing:


Here, the lower scan is wet mounted.  Certainly there is a touch more resolution here. Or maybe I focussed better… who knows ?

ScanScience claim a number of things, including:

- Better edge to edge sharpness: hmm. Probably, but with the “sandwich” mounting technique I’ve evolved over the years, and the relatively deep depth of field of the Minolta, I’m not - so far - seeing any benefit.

- Better contrast and detail: as shown above, yes, but we’re splitting hairs, to be honest.

- Extended dynamic range and saturation: Nope. Well, not for E6 slide film, at least. The Minolta covers the range of E100G and other low(er) contrast films quite happily, and has no issue at all with higher contrast.  However, this benefit may apply more to negative colour and black & white. I’ve yet to try this.

Hides dust & scratches: no. Absolutely not. If anything it makes things worse due to more places for dust to get in, and if dust gets into a fluid layer, it’s pretty much game over, time to remount.

So, in summary, I’m seeing minor improvements which don’t really appear to justify the cost and time.  But it’s not quite as simple as that. First of all, one thing is clear: to get any benefit at all, the image has be well exposed and sharp. Secondly, it seems that the benefits are more towards negative and larger formats.

There’s actually a lot of discussion out there on the interwebs about wet mount scanning, and by & large I’d say the overall impression is of mixed results. In particular, this discussion thread confirms my findings. Pity I didn’t do a bit more research…

At the moment I would tend more to reserving it only for “top picks”, but it’s early days yet.


Posted in Film | Silverfast on Wednesday, February 16, 2011 at 01:38 PM • PermalinkComments (7)


Tim Parkin February 16, 2011 - 8:00
Are you sure you've got the top two labelled properly? Looking at the colour differences in the bottom one and the sharpness differences, I would say it's the wet mount on the left and the dry mount on the right. I can see a substantial increase in sharpness and also less 'flare' ensuring the deep blacks and better contrast. It's often difficult to see even 20% increase in sharpness unless you have a very sharp original. The giveaway for me would be the ladder form on the pole at the top picture and the patches of contrasty water next to the rock in the bottom ones. You should probably have a play with how sharpening affects the two different versions (I suspect the wet mount will sharpen quite well at the pixel level).

Personally I found that dry mounting to the bottom side of newton glass gave me 95% of the way there (at least on my Epson) and so didn't bother wet mounting (although I was headed for a drum scanner so may have given up at diminishing returns). For negfilm though it would make a more significant difference..


david mantripp February 16, 2011 - 8:12
You're right Tim ... I can't tell my right from my left these days! :-)

Fixed now.

I have compared with and without sharpening, and I should also emphasise that these examples were the very best case scenario from a series of tests.

From what I can read, there are very clear gains with MF & LF film on Epson flatbed scanners. I'm not so surprised there, there's probably quite a lot of scope for improvement on my Canon 9000F as well.

I might try wet mounting to the scanner glass (I think Ctein mentioned doing that, and he has the same scanner). That may well end being optimal.


Robert Boyer February 22, 2011 - 6:32
Screw that - just gimme an 8000dpi Aztek drum scanner. If I am gonna screw around with getting stuff wet I want to be able to see the difference from a mile away.



Ps. There is a canadian that knows what they are talking about ?


david mantripp February 22, 2011 - 7:24
Had I a first-born or a grandmother to sell, I might be able to envisage that. As it is, I can't even dream about a Flextight (ps - isn't it so sad how some Flextight owners claim they're drum scanners... wannabeeism exists at all levels I guess)

Canadians ? Dunno. Neil, maybe ?


Robert Boyer February 23, 2011 - 3:18
Incidently I have been looking at used Flextight precision II scanners on eBay - The one I am looking at does up to 5x7 - nice unit but a little older - $2500ish - I am seriously considering this unit as my only sheet film capability in-house is a Microtek 900 or some such thing - good DMAX for a flatbed but.... leaves a lot to be desired vs a dedicated film scanner. You saw the BW scan on that latest post on my site but I really really want more. At least the quality of my Nikon 8000ED.


Ps There is also a Flextight precision III for about 7K but that is out of the realm of reasonability for me compared to the II - 7K will buy me quite a few drum scans (more images than I have that would even deserve such treatment.)


Robert Boyer February 23, 2011 - 3:20


Almost forgot - How do you like the 100G? Goods? Bads?



david mantripp February 23, 2011 - 8:43
I'm totally satisfied with it. For my purposes it's ideal - neutral, good dynamic range (for a slide film), low grain. I guess something like Velvia 50 might have even lower grain, but, well, that comes at a heavy price. And anyway, the scanner needs something to focus on!

(Thanks again to Tim Parkin for suggesting it. I'm a total convert)

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