Digital Photo 150 at Napa Valley College

Adobe Photoshop Technical Exercise #6: Global Adjustments


Different Image for each Demo


Original DSC_6832 is Titled: “Redwood Bending in Wind”

This is the original image before a black point and white point adjust made by using a new Threshold Adjustment Layer where the points are marked, then using a new Curves Adjustment Layer, where the points are set. I cannot upload .tiff nor .psd files so will use .jpg files to show the changes.

Interestingly, this is the image the camera saw, when the internal light meter registered 0, not a +1 exposure.  What attracted me to the image, and made me want to frame it, was the sun hitting the tree and creating such a contrast between light and dark, and having to stand in the wind to record it, and seeing the tree bent in the wind and the branches trying to tell us which way the wind was blowing, as if pointing to the left. “Oh, if only the tree could talk…”

After the black and white point adjustments

This process of adjusting the black and white point too away from the image and makes it look like a +1 exposure… When I do photography, I do not want to adjust the black and white points if it takes away from seeing the sky, as dark as it was… so when not doing this for a school assignment, I would see the terrible change, and click on UnDo….  I prefer the first image, which is “as I saw it”… This second image did not occur. The sky was much darker.

Exposure Adjustment

Original, before an exposure adjustment
Exposure was tweaked


I can tell, just by seeing the change in the green hue and the luminence of the yellow hue, and pastels of the lavender, that the 45 degree line of the curves palette was moved upward.  The mode was left to “normal”.  It was a Curves New Adjustment layer.  I moved the curve ever so slightly to tweak the exposure.


original exposure from camera, WB error
color corrected

This is not about exposure adjustment, nor brightness adjustment but this image is only about a color adjustment.  Global color at once, needed changing when I saw the caste in the original.  It is very obvious that the first image had a probable WB issue.

For this example of a color adjustment I found an image I thought had a color cast.  The method I used was from the screencast of making a new layer, filling it with 50% gray, setting the mode to Difference, Making a new Threshold Adjustment Layer, to get an exact grey point without guessing, Then discarding for making color adjustments, first with the new layer and making the 50% gray fill, then setting that filled layer to a Difference mode, and then making a New Threshold Adjustment layer to set a precise grey point, discarding those two layers, and making a Curves New Adjustment Layer, with the mode set to Color and  at this point, I used the grey tool to click on the spot found in the Threshold Adjustment layer earlier.  No other changes have been made to the image on the right.. the Left image is the original image… Next, I would adjust Exposure where I could also take a look at the Gamma.  I like to tweak Gamma too, with exposure adjustments, as part of my work flow.






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