photoblogography - Just some stuff about photography

Any colour you like

High praise for C F Systems

in Product reviews , Wednesday, June 03, 2009

I’ve been scanning slide film for ages. I’m on my 3rd film scanner (and probably the last, the way the market is going), but I only very recently decided to try working with negative film. I was tempted to do this after hearing about Kodak’s new Ektar 100 film. It sounded like it combined the best of both worlds: the extended exposure latitude of negative, and the definition of slide, and threw in excellent colour density into the bargain. Unfortunately, I haven’t used it yet, although I do have 5 rolls waiting for me to put them in the camera. Obtaining anything even vaguely esoteric in this sleepy cut-off corner of Switzerland is never easy, and one week was not a long enough lead time for my order to arrive before I left for the Eolian Islands. However, I did manage to find a 5 pack of Kodak Portra 160NC, which I was assured would be great for landscape (a lucky coincidence, since it was the only thing the shop had). So when I finished the few rolls of assorted Velvia 100F and Provia 400X I had found at the back of a drawer, I tried using it in my Hasselblad XPan.

The next challenge was getting it processed but I’ll gloss over that (try explaining to Hicksville Cameras that no, you don’t want prints, and NO you do NOT want the film to be cut ... ). Finally comes the moment of truth when it has to be fed into the scanner. I daresay that with experience you can judge the merit of a frame by eyeballing a negative, but I certainly can’t. So scanning is the only way to reveal what I’d actually photographed.  Turns out I’d spent a few days on Mars. Or had accidentally used colour infrared film. At least that was my conclusion looking at the results of SilverFast’s much vaunted (by them) NegaFix tool. This is supposed to characterise the stated film - and yes, it does included Portra 160NC in its list - and produce a beautifully rendered inversion to true colour. Well, to be blunt, it doesn’t.  I spent a frustrating day trying endless combinations of settings, fooling around with SilverFast’s arcane user interface, trying to convince myself that colour calibration was indeed disabled as it should be, but all to no avail. Everything ended up looking like a faded 1970’s Kodacolor snapshot.

I searched around on the web to find out if I was actually attempting the impossible: maybe Portra 160NC doesn’t work outdoors ? But instead I found a few examples of beautiful landscapes taken using it - and a reference to something I’d never heard of, C F System’s ColorNeg Photoshop plugin.  So I tried it.

I hate to say it, but the installation process for ColorNeg, at least on the Mac, is something of a challenge. And the user interface is, to put it politely, unconventional. But the results soon made me forget any superficial objections. I’ll say straight away, ColorNeg renders SilverFast totally pointless. In fact, it even introduces a suspicion that most of the vast array of correction tools available in SilverFast are mainly there to overcome glitches it inserts itself. With ColorNeg, all you need to do is a make a “raw” 16-bit linear scan, open the file in Photoshop, and point ColorNeg at it. Five times out of ten, ColorNeg’s default rendition is perfect, and the rest of the time a minor tweak of the lightness slider gets the rendition I want. Actually, since there is no “correct” way to convert a negative scan to display space, ColorNeg would need to be equipped with a mind reading interface to get it right every time. So problem solved: I can scan Portra 160NC.

But it gets better: ColorNeg has a sibling, ColorPos, which does the same magic on slide film. Again, scan at 16bit linear, point ColorPos at it, and hey presto, perfect result. This is unbelievable, compared to fiddling around in SilverFast or VueScan or whatever. I’m not going to even try to understand the mathematical thinking behind these plugins, which David Dunthorn, their author, describes on the C F Systems website, or the plethora of advanced adjustments available to the initiate, but what I do understand is that they work.  I have immediately adopted a new workflow - scan and archive raw 16bit linear scans, and convert them to display space in Photoshop using these plugins. This is a workflow I’ve been aware of for ages, but trying the various implementations of it using SilverFast HDR or VueScan has never convinced me.

It is really amazing that at this point in the evolution of digital imaging an individual could go back to basics and reinvent the whole process with such effective results. How come companies like Adobe and Lasersoft, with all their resources and experience, cannot do as well ? Probably because there is no commercial benefit to them. It is easy to bury non-optimal or even mediocre processes under layer upon layer of feature creep, which marketing has a far easier job with than selling the message “hey guys - guess what ? we got the basics wrong, so we’re starting over”.  David Dunthorn deserves far, far more recognition that he’s got.


Fumaroles on the crater of Vulcano. Colour reproduction by ColorPos

Registration is $67, which covers both versions, as well as GamSat, a colour integrity-preserving saturation adjustment plug-in which I’ve only peeked at so far. Excellent value for money.

(Read more about ColorNeg over at the Auspicious Dragon. Somehow I missed it when these posts were published last year)