Is color process could be made successful like a bw

[Athiril]

hrst: Contrast decreases with increased exposure too. What other reason? The best saturation and contrast point is obtained for x at x @ mid tones at box speed (unless you want to sacrifice by exposing less and pushing etc etc and other non-standard things) as defined by the manufacturer. People not seeing this I would suggest haven't experienced it, and there is some other reason for their improper exposure.

marK: No, the layers affect the other layers, on top of which increased exposure raises the minimum density of the complementary colour of the subject/area/point/etc. There'd also be greater stray absorption.

 

[2F/2F]

LOL my first question as well. Because Rolleis work miracles with shitty light, don't ya know

I love Rollei cameras, but they are certainly capable of being used for terrible pix. And this I know quite well from personal experience.........

 

[hrst]

hrst: Contrast decreases with increased exposure too.

I don't want to argue with you on this, but I want you to revise your thinking a bit. You are pissed about the net myth which is actually a faulty oversimplification, but you are actually making a same kind of faulty oversimplification yourself. Please.

Both are problematic assumptions that cannot be used as rules of thumb.

I summarize once again;

In cases where shadows are exceptionally low and hold important detail, overexposure increases contrast in them and underexposure decreases contrast in them.

In cases where highlights are exceptionally high and hold important detail,
underexposure increases contrast in them and overexposure decreases contrast in them (this is what you are talking about). This can happen with clouds, especially with sunsets and similar conditions.

The first one of these is probably more frequent because the linear part of the films is long and manufacturers want to take most of the speed available thus rating the films at the highest EI leading to "good" results. (Which is the basis of the ISO standard).

As a sum, in most "typical" conditions, giving a little bit extra exposure as a precaution will result in as much contrast and saturation as possible. Box speed is fine if you are carefully metering from "a little bit shadowy side of the midtones" or something like that. Or you can overexpose a stop "just in case" and then slack in the metering. This will not lead you to shouldering.

If you are seeing a change in contrast, that may be due to many reasons;
(1) we really are off from the linear part of the film
(2) you have some postprocessing problem or feature. For example, scanner CCD's have small toe and shoulder, furthermore you never really are scanning "raw", you have some piece of firmware and software that can do something unexpected. I have measured the characteristic curve of Epson V700 for example and it is not linear but it clearly starts shouldering at D=2.4, thus having lower contrast when scanning dense negs! You may be seeing this. This does not happen in RA-4 printing that easily.

And last, you cannot evaluate the neg with your eyes for contrast. Your vision system does not have linear response.

So, in those cases where contrast really changes, the perceived saturation changes accordingly. I think everything has been said regarding the contrast and cases where it really changes. And, the fact that a big part of perceived saturation is directly related to contrast. But, saturation can also change without changing the overall contrast. For example, Portra 160 VC and Ektar 100 have very similar contrast but Ektar has more saturated colors.

markbarendt;
"Each layer in color film only makes one color and it is always fully saturated because there is no other choice. The density is the only variable I see."

That's true, but densities resulting in from a given scene is not only dependent on exposure. They are also dependent on spectral sensitivities of the sensitization dyes in film. AFAIK, this is the variable that controls saturation along with image-forming dye absorption spectra. But I would expect this is constant regardless of exposure. I might be wrong. But at least we can control this by selecting a different film. At least I would like to hear if there is more to this.

For example, it is known that when printing with sharp-cut RGB filters instead of CMY filtered white light source, saturation is increased because of less crosstalk between the color channels, and this is different from contrast. So, there are more variables in the play.

 

[keithwms]

What is the way to get same colors at lower illuminated places as eye sees ?

This is the key: your eyes respond in a very different way to colour temp variations than film. Our eyes and brains do a pretty impressive adjustment to ensure that colours stay more or less true in shadows, and that works at least until the light is low enough to switch from cone to rod vision, then the colours are almost completely dehued.

But let's assume you have enough light that you're not seeing that nighttime monochrome effect...

In low light and shadow, you can have substantial changes from 5000K. this site seems to have a pretty good chart...

http://www.3drender.com/glossary/colortemp.htm

Some films will respond very poorly to deviations from 5000K. Others will do a bit better, but for the most part, if you really want to address this issue you need to get yourself a basic filter set and play around, and try some colour metering too if you can (n.b. a lot of digicams can act as colour meters and they are typically less expensive than a colour meter!).

Now, some films can handle mixed colour temps better than others. So as not to ruffle feathers, I won't mention specific brands that I didn't care for. There was one which reminded me of that terrible movie Ishtar. Anyway, I'll just say that I've had pretty good luck with fuji pro s and pro h in mixed / non-optimal light, and I thought reala was pretty good too.

The big problem with filtering is that it's very easy to overdo it. What drives me nuts is a landscape scene shot at sunrise or sunset which is nevertheless filtered to look like something else. One has to use restraint, of course!

And again, this is issue is quite separate from all the exposure stuff. Welll... okay, it's related in the sense that shooting colour film is kinda analogous to shooting several stacked, colour-filtered black & white films together, simultaneously. If you want to think that way, then to get the colours right, you will need to apply zone principles to expose each separate layer correctly. But the only sensible way to do that is to compensate for the colour temp as a whole. At least that way you aren't attempting to three or four coupled zone system problems

In other words, adjusting the overall exposure to all layers does not solve the problem of whether each layer is getting optimal exposure. That's why we filter.

 

[markbarendt]

I do agree that the layers affect each other, that's how intermediate hues are created, so what, that doesn't change the film's response curve.

No offense intended here but essentially you are asking us to believe that both Kodak's and Fuji's published technical data is wrong, in that the curves don't really have a straight line portion. You are also asking me to ignore the results of my own print results from bracketed tests.

 

[markbarendt]

In other words, adjusting the overall exposure to all layers does not solve the problem of whether each layer is getting optimal exposure. That's why we filter.

Absolutely.

It is also a good reason to use controlled colored artificial light. Strobes with or without gels, reflectors, scrims, ...

One way or another, balancing the curves in the camera with filters or lighting helps a lot.

 

[bblhed]

I really could not use this Rollei 35 S camera. And I have no lightmeter and it makes everything more complicated........................

Umut

A good light meter would cost you about the same as a few rolls of film but will save you many rolls of film over time by properly exposing them. I highly recommend buying one, you will not regret it.

As for color and the eye, your eye is a camera, but it is connected to a huge light, color and exposure computer called your brain. When you look at a scene you think you only look once, but your brain looks several times and each time it takes in different information and then provides you with the image that you "see" by filling in all the information it can from each of several images. Film can not do this, film looks once, and has to be exposed for only one light setting. You can shoot and process for whatever you want to, but you can't get the film to expose for several diffident types of lighting, there will always be some sort of compromise.

FYI: In the late 1800's a photographer who's name I can not remember did experiments with shooting several frames of film then used masking and cutting to produce a photograph of what his eye was seeing at the time. It is a complicated process, but it can be done.

 

[keithwms]

FYI: In the late 1800's a photographer who's name I can not remember did experiments with shooting several frames of film then used masking and cutting to produce a photograph of what his eye was seeing at the time. It is a complicated process, but it can be done.

Are you referring to the colour separation work of Prokudin-Gorskii?

 

[markbarendt]

markbarendt;
"Each layer in color film only makes one color and it is always fully saturated because there is no other choice. The density is the only variable I see."

That's true, but densities resulting in from a given scene is not only dependent on exposure. They are also dependent on spectral sensitivities of the sensitization dyes in film. AFAIK, this is the variable that controls saturation along with image-forming dye absorption spectra. But I would expect this is constant regardless of exposure. I might be wrong. But at least we can control this by selecting a different film. At least I would like to hear if there is more to this.

I agree that different films will have different color palettes. Ektar vs. Portra is a good example and that each film will have it's own unique response to any given input.

As I see it though, after choosing the film all we have control of are the densities involved.

My thought is simply that for any one given film there is only one color hue available on each layer and that when the three layers are "balanced and processed normally", the sum of the layers will always reach full design saturation.

I guess one way of saying this is that, even a perfect gray caught on color film isn't a monochrome or desaturated color, it's a fully saturated real world color created by a "balance" of density between all 3 layers.

We can manipulate contrast through composition, lighting, choosing the exposure relationships between our subjects and their settings, with polarizing filters....

We can manipulate the exposure relationships (balance) between the layers with colored filters to skew the densities one way or another to manipulate color balance. This is generally global though, with all the hues shifting say warmer or cooler, it may look better/provide better color contrast/be just what we want, but the saturation hasn't changed and our perfect gray subject from the scene is no longer gray.

For example, it is known that when printing with sharp-cut RGB filters instead of CMY filtered white light source, saturation is increased because of less crosstalk between the color channels, and this is different from contrast. So, there are more variables in the play.

I agree that deviation from the normal processes and tools could easily change the palette a given film might produce.