How To Use A Color Checker/Gray Card

http://froknowsphoto.com/?p=2990 Last week's FroKnowsPhoto Show someone asked how to use a color checker chart / gray card...here you go!

Category:

Education

Tags:

• xrite color checker chart
• lightroom
• nikon
• canon
• FroKnowsPhoto
• studio photography
• white balance

[beekydogg]

I'd love for you to make a video explaining how/when to use all the other colors at some point.

[Musicmixer1994]

I think you should put some cheap starter equipment and moving your way up...And talk about why and how you started photography

[rainerfilm]

Yes, you did forget something, what is the purpose of the colored blocks on the chart?

[c4dfreak]

PT V

You see each sensor lens combo changes. I would buy a light meter and calibrate it to my camera to ensure proper exposure. Colors change as exposure changes, if you need critical color and skin tones you need to use a light meter and calibrate the light meter to your camera.

If not then just make sure to set a custom WB based on your scene and take pictures in raw. I would also take a picture of a color card like the one he is showing here or a Color Checker Passport to create profiles.

[c4dfreak]

pt VI

in the middle of the grey card image, use your notes to see what image = which camera lens, and focal length was used to make that image.

Read the Mean: number. Mak sure you are in Channel RGB of the drop down. To see the Info for the histogram you may have to right click on the histogram tab and choose expand view. The mean is average of the R G and B channels and should read 128 or close to it.

Notice how each image changes based onthe lens to camera combo and the focal length.

[c4dfreak]

pt III

frame, make sure the card is evenly lit, the sun will be fine, (set wb to daylight) take a shot. Make a note, change the lens take a shot make a note, Zoom in zoom out take shots make nots of each one.

Take all the shots into Photoshop then look at the histogram, click on the little down pointing arrow with 4 bars, click expanded view also click window > then info. This will show you all the info for the histogram. Mean is over all average of the image. Make a rectangle selection

[c4dfreak]

Pt. II of the response. falling in the sensor. Each lens you put on the camera changes the amount of light falling on the sensor. If you want to see what I am saying, buy an 18% grey card (be sure it is a real 18% grey card) not a white balance card. This will be your reference. Take a shot in manual mode make sure the camera WB corrected and the exposure is reading dead center. The camera wont Auto Focus on the grey card so you will need to manual focus. Fill the frame, be sure to fill the

[c4dfreak]

white balance is a function of the camera adjusting to the actual light/color spectrum falling on the sensor. The camera does not know what is white or black. It knows middle grey or as it is known is 18% grey. You see the camera sets WB balance based on this 18% value it should be called 17.5% grey as from 0 to 255 (black to white) in the middle is 17.5. This sets exposure. A white balance card sets proper WB. Not the same a a grey card. Focus wont change WB it does changing the amount of light

[hyperfocus2011]

Wrong patch!

[hyperfocus2011]

@c4dfreak But does my focus choice change my white balance when Im in manual mode? Because the light changes with every product?

[c4dfreak]

PT IV

Please pay no mind to this fellow, for what he did with the target, one could use a coffee cup lid or a white sheet of paper to make a custom WB with any DSLR, Those targets are 80 bucks for so and he is using one patch to make a WB correction in post.Dont try that with Jpeg, It will only full work with a raw file. Colors will block up on a Jpeg, the info is been compressed and thrown away. Fro I know you know whats up, why let this guy clutter your channel. Fro knows photo but profiling?

[c4dfreak]

PT III

So when he said he doesn't have time to do custom WB during weddings just product shots, this really shows he is clueless. People pay big money for So Called Pros to shoot weddings then people like him show up and fake it.

All of the profiles created in the past live in the calibration section of the Dev module in LR. A word of caution, do not clip the target when doing the initial profile shot, it will be rejected when doing a custom profile. Make a proper exposure and all is good.