F/stops and Colors

Is there a specific f/stop that renders a particular color better then the rest,( example
f/22 renders yellow really close, but red looks washed out.) And say f/14 is best for
red, but the yellow looks to dark?

thanks,
Michael

It probably depends on the lens used. But I'm skeptical… I don't see how a different aperture could favor some color over the others.

The only thing the f/stop does is to control the amount of light that reaches the sensor, so I rather doubt it has any effect on color. Light is actually measured in kelvin degrees of temperature. Different colors each have their own kelvin temperature. I don't know that changing the f/stop would have any effect on the temperature.

I think this is a case of over/under exposures...some colors appear washed out (over) while some seem dark (under). There is a fine line of "perfect exposure" between over and under, therefore you can very easily see different variations in color between images if you are not spot on every single time.

Joe, does each color reflect light differently?

Michael

I am far from an expert on this subject. The way I understand it an object is a particular color because it reflects all others. A red object is red because it reflects all colors but red.

Joseph Bautsch said:

I am far from an expert on this subject. The way I understand it an object is a particular color because it reflects all others. A red object is red because it reflects all colors but red.

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It would absorb all other colors BUT red. What is reflected is what we see, the rest is absorbed

OK, I knew it worked something like that. I just got it backward. Thanks for correcting the error.

What about black and white? Does a specific F/stop render black and white differently than another F/stop would?

Different colored filters will render black and white differently!

I've heard a yellow filter will render a B&W pic warm...

Changing the f/stop only determines the exposure of the shot, making it darker or lighter. It dosen't change the white balance. Color in a shot is changed by adjusting the white balance in the camera, not the f/stop. F/stop is not used to do that because it has no effect on the color or white balance. Adding different color filters changes the white balance altering the colors that are recorded. Black and white is just that, black and white there is no color other than the gray tonal range from black to white. Using different colored filters with B&W film may change the tonal range of the B&W shot but it's still B&W. Most professionals who teach photography teach the triangle of exposure. To get the correct exposure or the exposure you want you have to make three settings on the camera, f/stop, shutter speed, and white balance. That's because each are independent of each other and are the necessary elements of correct exposure.

Very interesting discussion! Last semester, I took a course called "Color Theory" and here's the best way I can explain it:

Color and photography share similar principals in that they are both based on interpretations of light. Colors come from the spectrum of light, with each color producing its own unique wavelength signature. Receptors in the human eye are not capable of processing all of these wavelengths, and as such, cannot see all colors visibly (ultraviolet and infrared for example). Because the human eye is not standard (meaning everyone has a different set of eyes) not everyone will "see" the same colors.

The wavelength (color) that is produced is the result of a few different factors, including a subject's absorption and reflection properties. This means that a similar color will appear differently on different objects. The exact same wavelength frequency that produces red will look very different on a wooden barn versus an automobile for example.

Color theory works with HSL: Hue/Saturation/Lightness (RGB sliders in Photoshop can be changed over to HSL).

• Hue: a color's direction on the color wheel from white. Hues are the color's name, such as green, red, yellow, etc.
• Saturation: a color's intensity. Bright red is considered more saturated.
• Lightness: refers to the amount of black or white in a color. Maroon adds black to the red hue, while pink adds white.

Now....all the technical stuff aside and how this affects f/stops....I'm sure you can all figure this out. By changing f/stops you are allowing more or less light to enter the camera, which can change color values significantly. This would generally apply to manual mode, because the shutter compensates in AP mode and you wouldn't notice much difference.

Here is an interesting color experiment from this class:





One color as two:
Notice how the red color "A" appears to be different when placed against these backgrounds? The same with color "B". This experiments shows that our eyes make a color's overall distinction in comparison to its surroundings.

Two colors as one:
The opposite is also true. Colors "C" and "D" are different, but appear to be the same here. So do "E" and "F".

Fascinating subject and interesting exercise, Anthony.
It inspired me to pull a book off my shelf that I hadn't finished reading but remember that this author talked a lot about color and light (not as detailed as explanation above)

"Inner Game of Outdoor Photography" by Galen Rowell. I highly recommend it. When you look at his photos, you can see he obviously understood the connections between color, light, what the camera sees, what the photographer sees, and what the viewer sees. Plus, he shares so much wisdom about the art of photography . . . he died before he made it to the digital age, but this book is still very relevant. The tools may have changed, but not the art of good photography.

I was a printing ink color matcher for 25 years. I don’t know how relevant this is to this thread but I would like to point out that there has been discussion for years on what colors your eyes see best. This is what I was taught in the printing industry.

We all know the three primary colors that make up all colors are: Red, Blue, and Yellow. Based on the color wheel of the three primary colors. Your eyes see the color Red the best or any color made from Red more then any other color. Followed by the color Blue that our eyes find appealing. And finally the color Yellow which we have a harder time seeing any suttle changes.

I find this interesting because Anthony’s examples that he posted used the color red. Four out of the six base colors used are made from red. two from blue and no yellows.

Again, don’t know what this has to do with f/stops and colors, but I thought I point this out. Maybe this something you might want to remember when composing a shot when one of the three primary colors are more dominating then any other color.

AxeMan said:

...there has been discussion for years on what colors your eyes see best.

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Honestly, Officer, I didn't see the red light!

I agree with what Anthony says. Changing the f/stop changes the perception of color between colors but you are only changing the shade of the color from light to dark or dark to light by changing the overall exposure. That does not change the colors. They still come from the same part of the color spectrum they started out with. It's still the same color red whether the exposure makes it a darker or a lighter shade. There is no shift in the color spectrum, the blues do not shift toward the reds and the reds do not shift toward the blues. If a scene you are shooting is too blue, to correct it you do not change f/stops. You have to change the color spectrum of the scene by going into the cameras white balance and adding more orange/red.

The only way that I see the aperture affecting the color is by diffraction at small apertures. This diffraction would not alter the hue of the color, but rather the intensity or saturation. Different wavelengths (colors) of light will diffract at different rates depending upon the size of the opening (aperture) they must pass through.

LensWork, you are correct. A small aperture, usually f/22 or smaller can cause the the light to beak down to it's basic elements of red, blue, and green. Under certain conditions this can cause a multi color halo around the subject. It's not a shift in the color spectrum just a pulling apart of that part of the spectrum. More often than causing CA the small f/stop openings cause a deterioration of focus. CA is a greater problem in lens designs.