man & nature # 10 ~ variables #2
Wednesday, May 21, 2008 at 10:53AM 
Rustication • click to embiggenOn uesterday's entry, Tom Frost (AKA, Stu Newberry?) called for a reality check of sorts when he opined, "Uh, chemical photography is "immature" in the sense that people's ability to use it (the RAW conversion for you digital people) varies tremendously. Also, I don't think anyone would expect the same results from Velvia vs Kodachrome or Tri-X vs Bergger BPF 200, not to mention the variables in development. Oh, and don't forget, then there's the printing..."
He has a point but it seems that he missed my point - sure enough, there were/are variables aplenty in the film capture domain. Although, it should be noted that the variables with color photography are severely restricted to the choice of what film to use. Unlike its BW film counterpart, color film processing is pretty much a by the book / numbers affair. A little push here, a little pull there with E-6 chemistry was possible but not so much with C-41, but, again unlike BW film, those 2 chemical processes were just about the only choice you had.
Be that as it may, my point was/is this - your results from color film, negative or positive, were determined by the film you used, NOT by the camera you used. If you wanted the Velvia look, you used Velvia in any camera of your choice and, viola, you got the Velvia look. Nikon, Canon, Olympus, Minolta, Pentax, Leica - pick a brand, any brand and you still get the Velvia look. The same holds true for Kodachrome, Ektachrome, Vericolor, Ektacolor, etc. - what you use is what you get no matter what camera you use it in.
That's the standard / consistency I am referring to.
To a lesser extent, this also applies to BW film domain as well - sure there are a zillion film / developer / paper combinations that can be used to obtain a wide range of results, BUT, in each and every case, you started with a known quantity, i.e., a film / developer / paper with known characteristics (no matter what camera you used the film in) from which to do your voodoo magic.
In the digital capture domain there has been a huge paradigm shift - the camera itself determines the color, dynamic range, hue and saturation, contrast / tonal characteristics, etc. of your image capture. So, in a very real sense, one must be both educated and aware of these differences between various camera brands (as well as the differences even within different models of the same brand) when making the choice of what camera to use.
In the digital domain, the camera is no longer a relatively neutral mechanical device. Each and every camera adds its own flavor to the mix.
And god help you if you choose a RAW converter that doesn't work well with your camera flavor - as an example, ARC in particular doesn't seem to work well with a number of camera brands, or, at least, with a number of camera brand models. I and many others have noticed that some manufacturer's propriety RAW files, when processed in ARC, exhibit a characteristic called "watercoloring". A condition in which colors tend to smear and get blotchy much like watercolors do on paper.
The biggest part of these problems is the fact that every camera manufacturer has its own proprietary file format. IMO, this serves only the camera manufacturer as a purely marketing device, not the picturing public as a picturing device. That is why I fully support the idea of DNG - a "universal" format that promises at least some level of "consistency" from which the individual can then go to town in the digital darkroom to create any possible result that their heart might desire.
Then, and only then, will the photographer be truly free from the dictates of what software engineers (and film engineers / chemists) think our pictures should look like.
Reader Comments (3)
There is another subtle factor that plays out in both the film and digital world - and that is the lens. Each lens "draws" differently - differences may include contrast, color (typically due to coatings), bokeh, etc. - certainly not as important as your choice of film or RAW converter, but worth noting.
Another related note -- I often shoot color slide film side by side with digital for night photography, and use the slide film as a model for processing my RAW files.
Cheers,
Joe
The idea of a universal and consistent raw format is appealing, but more than one major manufacturer (perhaps all of them?) is doing quite a bit of processing to their "raw" files that one would hope would only be done to JPGs. They are not truly raw. This would make the consistency you seek much less likely. Storing the data as a DNG doesn't provide a consistent level of "rawness". DNG does provide a format that can be read consistently, like uniform sprocket holes in film, and this is a good thing.
As far as I know, my camera, the SD14, is the only one that has a closer to true "raw" format as there is NO interpolation at all in the camera with there being no Bayer array sensor in it. ACR does make a mess of the files too. I've rarely used it. I really stick to the software from Sigma to convert to TIFF with usually very few adjustments.