CatMarley Loc: North Carolina

My palms are quite pink! Doing a selfie off your tee shirt is a lot better!

DirtFarmer Loc: Escaped from the NYC area, back to MA

As CatMarley notes, my palms are also pink in appearance. So I tried using my palm.


Here is the white balance eyedropper on my palm.



Setting the white balance with my palm does not look realistic.



There was a piece of white paper in the image so I tried that



The white balance set to the white paper looks better. There is a difference from the original photo.

no12mo

I like this

Pixel-pusher

A credit card sized gray card in my wallet works wonders.
However, if I didn't have that, every camera I own has a more-or-less color calibrated built-in flash.

Step 1) I would move close enough to the critical colored object for the illumination from the camera's built-in flash to overpower the questionable light source and take a calibration shot.
(In some situations it might also be possible and helpful to block some the light from the questionable light source.)

Step 2) I would then close the flash, move to the desired location and take the photo I want.

Step 3) I would then use my photo editing software to make the colors in shot 2 match the colors in shot 1.

GrandmaG Loc: Flat Rock, MI

Funny you should mention that. I was just reading about 18% gray not being neutral. Also, so smart to take a picture of your red hat!

GrandmaG Loc: Flat Rock, MI

Neat trick!

Timmers Loc: San Antonio Texas.

It is important to correct silly information, and I will not wade through pages of posts. Light meters are calibrated to 18% gray, period. You will find 18% gray in Photoshot in CURVES, it is the mid point where all the grid points meet in the center. A Kodak Gray Card is a neutral density attenuator (just like a polarizer is a neutral density attenuator and not considered a filter). Kodak prints the gray surface to be .80 (mid point) plus or minus .79 to .81, the reason the Kodak Gray Card is NEVER recommended as a standard color target is because Kodak coats the paper with inks to get the correct density.

The Kodak Separation Guide contains a printed gray scale on photographic paper, it has THREE (3) calibration points marked as letters 'A' 'M' 'B' Where the 'A' is just detail in high lights (Zone 7), 'M' is the mid point also 18% Gray .80 +- .01 (Zone 5) and finally 'B' which is detail in shadows (Zone 3).

There is a dumb but old ethnic joke to help remember the three letter code, "If USS is United Sates Ship, and HMS stands for His/Her Majesty Ship; then what is the meaning of the Italian Navy designation AMB stand for? "Ats My Boat" (I'm Italian by the way).

For Kodak systems, a negative is properly exposed and developed, then printed on a 'standard' grade of paper, the dried final print by visible inspection is printed for the white, the letter 'A', then the exposure was correct and also the development when there is just off paper white in 'A' and the 'B' is on the letter 'B', if higher or lower by a single square of 'B' then the film was over or under exposed by 1/3 stop by counting the patches on either side of 'B'. Once this relationship for YOUR printing conditions has been established the final step is to evaluate the 'M' square, this as to do with the concentration or agitation of that developer with that film sample.

So the printed gray scale that is with the Kodak Separation Guide is as accurate as a calibrated Kodak Gray Scale used to establish calibration for a densitometer, especially a reflectance densitometer.

Now that we have laid the solid foundation of the Kodak Gray Scale and the attenuator used to make accurate readings for photography, what is this 12.5 density for light meters in cameras? 12.5 is 1/3 density shift from 18% gray. ALL light meters should be calibrated to the .80 density or 18% gray. It is a standard. Back in the late 60's and especially the early to late 70's camera manufacturers used a different calibration of 12.5. This was for most 'armature' marketed cameras, or what are referred to now as consumer cameras. Why 12.5? Because they shot mostly in landscape compositionally and frankly they were not knowledgeable enough to tilt the camera down slightly to avoid under exposure from the strong sky in the scene.

Why would Kodak go for such a thing? Because Kodak has always catered to it's amateur market. A slightly over exposed negative is better than an under exposed negative. Now many will think I am blowing smoke up your ass, I'm not. If you do a strict parametric test of a Kodak B&W film you will know to expect about one full stop of speed GAIN when running a precise systems index calibration with the zone system. I swear I am not making this up. In fact it is the first step in teaching hands on zone system for students when teaching the basics of zone system and the EI (Exposure Index) for a film.

If you have a hand held meter it should be calibrated to 18% gray/.80 density. If not there will be a dial on the rear of the meter that allows movements of 1/3 (.10) density shifts. So if you wanted to shift your hand held meter from 18% gray to 12.5% gray you simply move the calibration on click of the dial.

burkphoto Loc: High Point, NC

THANK-YOU! ...for ringing the BS alarm on the 12.5% misunderstanding. No doubt some diehards remain...

Rongnongno Loc: FL

Using the back of the hand.... Better exposure short of everything else.

Better exposure allows for grey point and IS NOT MEANT to change the white balance. Trying to use something of any color to change a white balance is not only silly but stupid. It is the same as trying to use a leaf (green) to set the white balance.

Every color has a luminosity value. Know that like.... the back of your hand and you stop guessing.

This (color) luminosity value is the reason for selecting a color when 'painting' grey. That way you have a constant value when 'painting'. This beats using transparency/opacity and the like.

Many seem to forget that the 'grey point' refers to a B&W luminosity value.

nekon Loc: Carterton, New Zealand

12.9% get it right, it's a fact. I have been a pro photographer for 55 years, and this information was given out by Kodak in the 1950's. No smart arse comments can argue against this.I use grey, black and white cards by Mannon , and a Gretach-Mcbeth colour checker.

nekon Loc: Carterton, New Zealand

... therefore I have no problem with e xposure or white balance.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Does it really matter if any light is not truly neutral?

The entire point of color management is to remove any color cast contribution from the equipment or media used in recording and displaying an image. Ideally a live red rose should look very close in color and tint to a picture of a red rose. Good color management policy will help ensure the red rose isn't purple or green - regardless of what light you are viewing both the real rose and the picture.

blackest Loc: Ireland

I think what confuses things is 2 gray cards one for setting exposure and the other for white balance.

when people shot film exposure was the setting that you were trying to get right, if you are not using colored filters then lightness / tonal value is enough so grass back of your hand , Sunny f16 pretty much work for exposure.

A white balance card is designed to work under different lighting conditions to render neutral tones neutral. That tends to be what most photographers aim for most of the time. You probably don't want this for a sunset or sunrise.

I think most of us have some idea of how colors are recorded as red green and blue components. Those filters are not perfect each channel is going to be contaminated with the wrong color light. Camera manufacturers are not dumb they know this and use a color matrix to discount the values recorded in each channel, this works fairly well with a wide spectrum source such as sunlight but it is going to be a tad different between cameras Nikon probably will tend to balance towards a Nikon color balance and Canon to a Canon color balance. Side by side there will be a difference. They are not so much going for color accuracy but an attractive image.

Then there is Light, if you have a sodium street light as illumination then thats a narrow spectrum of light and there will be a lot of light that goes into the wrong filters. They can and do rejig the color to compensate but only in a general way, they can't rejig to the light you are having to work with especially if it is mixed light sources.

There is also filters, these can mess with color and balance too. In video there is a 180 degree rule if you shoot 24 frames per second your exposure time should be 1/48th if 30 frames a second then 1/60th If you don't then each image jumps and movement gets jerky. You don't want to change aperture as that messes with depth of field and you want the iso as low as possible in order to have least noise and maximum dynamic range. With all 3 sides of the exposure triangle locked the only way to control the light is an nd filter or fader (a fader is a variable ND filter) in a perfect world an ND filter would be neutral but its likely it will not be.

This is why a color calibration target becomes useful having known colors as a reference a profile can be created for your specific lighting situation and that profile should be pretty close to correct for these photos.

There are also dual illuminant profiles you use a combination of two target photos shot under different lighting e.g daylight for one and CFL for the other with a certain amount of wizardry these dual illuminant profiles should produce good results from your camera under different lighting conditions, this is magic i do not understand.

It's worth pointing out that if you are shooting jpeg a lot of processing has gone into making an "attractive" photo. Much of it in the form of curves if you are editing a jpeg you are adding further curves which are being distorted by the curves baked in. With a raw file you don't have to work with this processed data and your photo will look better than an adjusted jpeg.

However after saying all this , most people seem to want an attractive image rather than an accurate one, for many people this is just over kill.

Mr palmer Loc: Currently: Colorado, USA, Terra, Sol

And before the sensor? The film was developed to that same standard? Interesting. I was taught - a couple of eons ago - that it was a discovered phenom that most palms, from whatever race, reflect within about a half stop of each other. So, the truth is finally revealed. The world has largely changed palm colors to conform to a white American model in NY. The power of the American Dream! Or maybe we all changed colors to follow American Corporate Ingenuity? Or maybe humans developed similar reflecting palms during the Neanderthal Period in an attempt to use their hands to bounce on-camera strobes, before paper was discovered.
Wow!
Good to know.
And they said "knowledge never hurt".

sbohne

Evidently, there was some misunderstanding. Taking a reading off your palm is for exposure only… Not for color balance! Nobody has pure white palms. And if they have 18% gray palms, they have a larger problem than exposure!