Amazing write up and research - We need more of this!
My feeling is most people who are going to be interested in the slight increase in color accuracy are already drum scanning or using a virtual drum scanner like a Imacon flextight, and the team at Imacon has some crazy color scientists working on that as evidenced by the images it outputs.
The quest for the most true colors from C-41 feels like a pointless exercise in ways. When i print RA-4 in the darkroom i am working with a set of color correction filters and spinning dials to mix color on my enlarger head. The resulting print is my interpretation of the negative.
Back in the 1-Hour-Photo Minilab days, the tech was doing more or the less the same thing as well, or just hitting 'auto' and the Noritsu or Frontier was making adjustments to each frame before printing it.
If i am scanning the negatives with a camera and light source and after inverting, a greenish mask is still present, as like in the first conversion example they give, a few tweaks of a few sliders in photo editing software is enough to correct it.
The bigger factor at play here in my mind, is the availability of robust and consistent color developing services. Most indie labs these days are using C41 kits and at best a Jobo machine. There are very few labs even offering Dip and Dunk with a proper replenishment cycle with chemistry from the big players like Fujihunt or Kodak Flexicolor.
A a half a degree off temp, or a developer that near its rated capacity is enough to megafuck the resulting negatives.
There is an even worse trend of indie chemistry manufactures offering C41 kits with seemingly innocent replacements, that have huge consequences. For example one indie manufacturer in Canada is shipping there kits without a proper Color Developer (CD4) and instead using p-Phenylenediamine, which guarantees the incorrect formation of dyes
Sorry if i sound negative and got on a rant, i really do love this sort of research.
Drum scanning is crazy time consuming and expensive. I shoot hundreds (sometimes thousands) of film photos per year and 99.999% of my scanning is done with a camera and a backlight.
what kind of camera/lens have you found to be the best for this?
Not OP, but any macro lens will do the job. You're not likely to be shooting at a wider aperture than f8 given that you'll need some depth of field to spare. (Even if you use a specialised copy lens with a flat field, the film won't be perfectly flat anyway.) So given that you're shooting an imperfectly flat piece of film at a narrow aperture, differences between lenses will be small. I use an ancient f3.5 Micro-Nikkor. These are cheap and plentiful in the second hand market and can be adapted for most cameras.
As far as the camera is concerned, it's a big advantage to have an electronic shutter. The effects of camera shake are magnified with macro photography, and a mechanical shutter can make the results observably softer. I am cheap, so I use an old DSLR in T mode and use a Raspberry Pi to turn on one of those backlit sketch pads for a fraction of a second to expose the image.
To add onto this - I highly recommend you take advantage of light rooms Flat Filed Correction tool, it will eliminate lens vignetting which can cause issues when inverting. This article elaborates https://www.pixl-latr.com/defeating-the-orange-haze-lightroo...
That looks very useful for use with older lenses. With a modern lens, shouldn't Lightroom be able to apply a precise vignetting correction based on the image metadata and the lens parameters?
Cross polarised light (to eliminate specular reflection) and a home made vacuum bed is 99% of the way to a seriously pro scanning tool.
A setup like that helped me get through 15k prints in no time with excellent results. The biggest barrier to success was after churning through the 7x5 and 6x4 shots, things got a lot harder with variable sizes of print. It really slowed the process down — and conversely, uniform print sizes made the first 90% of the job almost enjoyable. I averaged one “scan” every 2s.
I’m not sure the indie, non megalab chemistry kits ought to be so easily dismissed. I have had fantastic results working with Tetenal Colortec in the past with really not that much more than a shift in the cyan direction. And this was using a kitchen sink for thermal stability.
C41 is such a toilet process anyway — everything is shades of brown?! — that I can’t imagine anyway would look for precise color work from it the same way I can’t imagine anyone would look for resolution for 135 stock.
It turns out that you don’t care. Maybe you can think of brown as a color that filters out blue light. You can counteract it by shining more blue light through it. Maybe not exactly blue, but some light mixture. In the end it doesn’t matter, except when you look at the negative with your eyes.
The orange mask is there to increase color accuracy, counterintuitively.
https://photo.stackexchange.com/a/109979
I hear you. Its pretty amazing what can be accomplished at home in your kitchen sink. But sometimes the devil is in the details and little things like a shift in sky colour across three or four rolls is enough the ruin a consistent look you want
I worked in a minilab one summer. The Noritsu printer had, IIRC, a +/- 1,2,3 override for R,G, and B. So if you saw a head over a big blob of green (someone wearing a red shirt), you'd hit +2 Red to override the printer's attempt to "balance out" the colors.
We never got any 'interesting' stuff. I suspect people would prefer a bit more anonymity than you would get from a 2-3 person shop where the person who printed your stuff might also be the one ringing you up for it.
My father owned a photoshop that was a one-hour lab for the last decade of its life. I worked for him throughout my teens and have printed many thousands of photos. I've seen interesting stuff. Most of it is pretty boring.
Not only did we get interesting stuff, but we would routinely print a few extra prints for a photo album we kept in the back.
This takes me back. I worked in a one-hour photo place way back in the day, operating a Noritsu. We had a film school in town and students would often come in with their C-41 or their Tri-X and complain about the colors or saturation of their prints. Which was totally fair, because tapping the right CMYK buttons on the machine was more art than science. Ah, memories.
Tri-X is traditional gelatin silver black and white.
Yeah—and do you know what happens when you print it on color paper? You get inconsistent colors between the highlights and shadows. So, people would complain about it.
Are new drum scanners still being made out of interest? It appears fairly hard to find used ones.
They sound a bit awkward to use from what I've read, as I think you need to use liquid to adhere the film to the drum correctly?
I think used drum scanners were always somewhat hard to find and somewhat expensive.
Not strictly necessary, but strongly recommended. You can also use wet mounting for your flatbed scanner. There are conversion kits so you can use wet mounting with an Epson or Canon flatbed.
Wet mounting solves or reduces a lot of problems, like Newton rings / keeping the negative flat and in focus, dust, scratches, water marks.
Apt
The other thing about drum scanners is that you can do color correction by adjusting gain / response curves somewhat during scanning.
I haven’t done this, but when I had images drum scanned, I provided a reference for how the colors were supposed to look and the technician matched the reference. My reference was just a flatbed scan of the same negative, which I had color corrected myself.
I think this is a major point. I applaud the effort of the post and would (as a Mamiya 7 shooter!) love a whole unit better than the Epson V600, but correcting a color cast in the film scan is trivially easy in an photo editing tools these days. I scan and get tifs and can tweak to whatever. More important are the iris/optics of the scanner itself and how flat the film is inside the bed.
This is interesting. I still shoot a fair bit of medium format film and I have to say that I'm not looking for _accurate_ color so much as _attractive_ color.