How does Fuji Velvia accomplish such saturated colors?

I can routinely get more accurate outdoor colors with Ektar than with almost any other color film I've ever used. And I'm talking about difficult subtle hue distinctions. But this requires both an understanding of how this film works, esp per color temperature, and precise printing skills. It is not oversaturated whatsoever. The weak point is probably in subtle distinctions between orange-yellows and yellow-oranges, though it's much better in this hue category than any other color neg film. And notoriously, blue shadows can become annoying if you don't know how to correct for them in the initial shot. Not a sterotypical understated skintone film, however. And when it comes to chromes, the late great Fuji Astia was probably the most correct overall, but poor in certain conditions. There has never been a silver bullet out there that worked best for everything. I remember how old school pre-E6 Agfachrome would precisely pick up fluorescent lichen colors and complex mineral golds and browns that no other film since has been capable of, yet was horrible at green reproduction. There are certain subtle shades of early Spring "Irish" green which only Velvia and E100S seemed capable of bagging, provided you had one of the
very rare lenses capable of recording these distinctions. Printing them was next to impossible. But over time, people who get accustomed to the idiosyncrasies of a particular film and learn to print well with it anyway kinda lull themselves into the subconscious myth that this is
how the world really looked. No film is perfect by a long shot. But it sure helps to recognize this fact, master one or another, and live within its parameters. Or of course you can just defect to Fauxtoshop and start learning how to throw colored Jello onto things, just like in
Kindergarten.

Is the world we live in really so dull? Well, maybe it is. I think we humans have endless imagination and overly active brain making us see everything vividly, most probably for evolutionary reasons. It is probably an advantage for instance to recognize red color immediately (probably blood or something poisonous/dangerous). Velvia is so popular a color film because it works like our brain, increasing contrast and color saturation to see "better". The only thing film could not implement yet is selective ISO depending on regional brightness, like our brain does.

Ever look at Euglena chloroplasts under a microscope, or even an intense Euglena bloom in a pond? No film ever made is even capable of
rendering that intense a green. Otherwise you control the contrast as well as relation of intensity of the hues during printing. Of course, nowadays everyone just wants to push a button and have everything done for them, but that's not how carefully nuanced images come into
existence. The film is only one component in the workflow. But as usual, there's a distinction between color and noise. The manner we perceive the intensity of color is as much related to how hue are modulated in relationship to one another than to the mere hypothetical saturation. Why does a discrete spot of a color look so much more intense in a neutral field than plastered all over an entire canvas? There's more to this game than just cranking up the volume.

Photo Engineer said:

Ektar 100 uses the methods in my post to get higher color saturation. They use higher contrast. Portra does not.

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There has to be more to it than higher contrast, or my pushed Provia 400X or Portra 400 would look like Velvia/Ektar. Maybe higher contrast is just one of the necessary requirements for achieving higher saturation.

Sure would be fun to know some of the dye science behind this, but that's a complicated field in its own right, and I'm sure certain aspects of
this are pretty well guarded when it comes to the details.

Rudeofus said:

There has to be more to it than higher contrast, or my pushed Provia 400X or Portra 400 would look like Velvia/Ektar. Maybe higher contrast is just one of the necessary requirements for achieving higher saturation.

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Interimage is another way to improve saturation. This is done by manipulation of Iodide release and the use of DIR couplers.

PE

DREW WILEY said:

Sure would be fun to know some of the dye science behind this, but that's a complicated field in its own right, and I'm sure certain aspects of
this are pretty well guarded when it comes to the details.

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The method is fully outlined in several patents and articles so it is no real secret.

All dyes are impure and thus a cyan has some magenta and yellow in it making it look duller than it should. So, by the use of selective inhibitors (see my previous post), such as Iodide or PMT (attached to a DIR coupler), the adjacent magenta and yellow can be inhibited by a given amount and thus there is more "purity" to the cyan. Basically, a positive magenta and yellow image is formed wherever there is a cyan negative image and thus correction is achieved. This is referred to as masking but it is an integral mask. You are familiar with masking Drew so there is no magic here. Just the controlled release of an inhibitor. The amount released can overcorrect, thus giving brighter and intensely saturated images. Ektar 100 uses more of everything compared to Portra.

As for controlled ISO, negative films have that. The long latitude lends negative films a great degree of controlled latitude such that Portra 160 can be exposed as low as ISO 50 and as high as ISO 800. The changes seen in the image quality are very similar to those obtained by "other imaging systems" .

PE

Photo Engineer said:

So, by the use of selective inhibitors (see my previous post), such as Iodide or PMT (attached to a DIR coupler), the adjacent magenta and yellow can be inhibited by a given amount and thus there is more "purity" to the cyan. Basically, a positive magenta and yellow image is formed wherever there is a cyan negative image and thus correction is achieved. This is referred to as masking but it is an integral mask. You are familiar with masking Drew so there is no magic here. Just the controlled release of an inhibitor. The amount released can overcorrect, thus giving brighter and intensely saturated images. Ektar 100 uses more of everything compared to Portra.

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I made a similar argument on page 1 of this thread, but this theory seems to only work for color negative film. In the case of slide film you would actually have to accelerate development in adjacent color layers in order to boost saturation. That's where I got stuck ...

They use selective release of special compounds called DIAR couplers.

Thanks. That is also how the "self-masking" feature in second-generation Ilfochrome worked, though in that particular case, far less successfully in terms of color reproduction. You still needed supplementary masking not only for contrast, but for color.

Photo Engineer said:

All dyes are impure and thus a cyan has some magenta and yellow in it making it look duller than it should. So, by the use of selective inhibitors (see my previous post), such as Iodide or PMT (attached to a DIR coupler), the adjacent magenta and yellow can be inhibited by a given amount and thus there is more "purity" to the cyan. Basically, a positive magenta and yellow image is formed wherever there is a cyan negative image and thus correction is achieved.

Click to expand...

Nice to know I wasn't imagining my density measurements!

Photo Engineer said:

They use selective release of special compounds called DIAR couplers.

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Do they use DIR/DIAR couplers in E6 film? Your posting (there was a url link here which no longer exists) implies only C-41 films use them.

DIR couplers release inhibitors instantly upon dye formation and thus can affect the layer that they are contained in. This can have a good effect on sharpness. DIAR couplers undergo timed release, forming inhibitors only after a given time of diffusion.

Since it is usually normal to get interimage effects in E6 in the FD, because the CD goes to completion, it is difficult to get DIR couplers to work properly in E6. Well, for that matter it is difficult to get DIAR couplers to work properly for that matter. In any event, DIAR couplers, being timed, can effectively be used in E6, although color correction as I have stated repeatedly, is more difficult in E6 even if DIAR couplers are use.

And since DIR couplers have more activity locally in an emulsion, it is more common to rely on the FD for local effects by using graded iodide. IMHO, it is more difficult to design an E6 product with good color and sharpness for just these reasons.

PE

PE, how much color correction does the action of the DIR/DIAR couplers do compared to the mask in a negative? Most of it, or does the mask still do the bulk of it?

RPC said:

PE, how much color correction does the action of the DIR/DIAR couplers do compared to the mask in a negative? Most of it, or does the mask still do the bulk of it?

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Both work on completely different aspects: the orange mask corrects inherent weaknesses in the dyes, whereas DIR/DIAR couplers are used to adjust contrast and saturation. The mask acts in its own layer but has no effect on other layers, whereas DIAR couplers are specifically designed to affect only/mostly the other color layers. Unlike mask, DIR couplers reduce contrast in the same color layer, but do not change the exact hue of the dye.

The mask has no influence on sharpness, but the DIR and DIAR couplers influence sharpness quite a bit.

PE