Curves
May 3, 2015 08:16:12 #
Can any members help me to understand "Curves" it's the one area with PP I haven't got clue about.
I have tried using curves but I really don't know what I am doing so any help will be appreciated
I use Zoner Photo Studio usually and sometimes PSE 12.
Many thanks,
John.
I have tried using curves but I really don't know what I am doing so any help will be appreciated
I use Zoner Photo Studio usually and sometimes PSE 12.
Many thanks,
John.
May 3, 2015 09:05:18 #
I've been meaning to get into that more myself. Maybe these:
http://www.youtube.com/watch?v=abn21tnEKeA
http://www.photokaboom.com/photography/learn/Photoshop_Elements/curves/1_curves.htm
http://www.youtube.com/watch?v=abn21tnEKeA
http://www.photokaboom.com/photography/learn/Photoshop_Elements/curves/1_curves.htm
May 3, 2015 11:36:47 #
Frankly, I tried "Curves" for a long time and finally switched to "Levels". To me, Levels seems to offer the same thing as curves, but with easy to understand "sliders", rather than trying to guess where to grab the curve and how much to pull on it. I've heard people say Curves is better, for some reason or another, but I'm sticking with Levels.
May 3, 2015 12:15:18 #
Curves is just an application the graphs we all had to study in high school math. If you truly understood graphs then, curves should be straight-forward now; otherwise, otherwise. The horizontal axis shows the current brightness of pixels, and the vertical axis specifies a new brightness. If you pull a region up, all pixels of that brightness will become brighter; if you pull it down, they will become less bright. This provides precise control over any particular region of brightnesses. When the line is steeper in an area, the contrast is greater; when the line is less steep, the contrast is less. In the terminology of math, the software forces the line to remain continuous and differentiable - in other words, no gaps and no sharp corners.
The main time I use curves is when I want to tweak contrast - to reduce apparent differences that aren't really there, or to emphasize differences that are hard to see (for example, to see border between a shiny roof and the sky - when I probably should have used a polarizing filter in the first place)
The main time I use curves is when I want to tweak contrast - to reduce apparent differences that aren't really there, or to emphasize differences that are hard to see (for example, to see border between a shiny roof and the sky - when I probably should have used a polarizing filter in the first place)
May 3, 2015 13:33:17 #
Levels adjustments are linear and straight forward.
Curves offers a 'three dimensional' adjustment. As such they are slightly more complex BUT if you use the bottom sliders you can make it behave like a level adjustment of sorts.
My suggestion is to use levels with a luminosity mask and use the 's' shape adjustment.
Red extreme Level adjustment.
Green s-shape adjustment.
Curves offers a 'three dimensional' adjustment. As such they are slightly more complex BUT if you use the bottom sliders you can make it behave like a level adjustment of sorts.
My suggestion is to use levels with a luminosity mask and use the 's' shape adjustment.
Red extreme Level adjustment.
Green s-shape adjustment.
May 3, 2015 15:00:48 #
johneccles wrote:
Can any members help me to understand "Curves" it's the one area with PP I haven't got clue about.
I have tried using curves but I really don't know what I am doing so any help will be appreciated
I use Zoner Photo Studio usually and sometimes PSE 12.
Many thanks,
John.
I have tried using curves but I really don't know what I am doing so any help will be appreciated
I use Zoner Photo Studio usually and sometimes PSE 12.
Many thanks,
John.
Elements doesn't have a Curves feature like the one in Photoshop. The Curves feature in Elements (called Color Curves) doesn't have as many preset settings and as many adjustment points as the one in Photoshop.
http://helpx.adobe.com/photoshop-elements/using/correcting-color-casts.html#adjust_color_curves
If you want a fully functional Curves feature, you could use SmartCurve, a third-party plug-in (Windows only).
http://www.softpedia.com/get/Multimedia/Graphic/Graphic-Plugins/SmartCurve.shtml
This will help you understand Curves.
http://www.photoshopessentials.com/photo-editing/levels-curves/
May 4, 2015 09:05:31 #
Rongnongno wrote:
Levels adjustments are linear and straight forward.
Curves offers a 'three dimensional' adjustment. As such they are slightly more complex BUT if you use the bottom sliders you can make it behave like a level adjustment of sorts.
My suggestion is to use levels with a luminosity mask and use the 's' shape adjustment.
Red extreme Level adjustment.
Green s-shape adjustment.
Curves offers a 'three dimensional' adjustment. As such they are slightly more complex BUT if you use the bottom sliders you can make it behave like a level adjustment of sorts.
My suggestion is to use levels with a luminosity mask and use the 's' shape adjustment.
Red extreme Level adjustment.
Green s-shape adjustment.
:thumbup: :thumbup:
May 4, 2015 09:25:22 #
Since I use different editors than you do I can only make some general comments about using curves, but my first comment is that there are a lot of different uses for them so any advice you should take with a grain of salt.
That being said, most of the curve tools I've seen are used to make adjustments to brightness levels. There is a graph that you can think of as plot with the horizontal axis representing light intensity before the adjustment and the vertical axis as representing the light intensity after the adjustment. When the graph itself is a straight line from the lower left to the upper right of the diagram, there is no adjustment - after is the same as before.
You may be offered a variety of ways to distort that straight line - sliders perhaps but often some variation on the idea of clicking at some part of the line and dragging it up or down with the mouse. If you pull up on the left part of the graph you brighten the darker parts of the image while if you pull up on the right side of the graph you brighten the already brightest part of the image. As with most tools on a computer you just need to experiment to get a feeling for what happens. Generally you can find some way to undo what you have done if you don't like the change.
One thing that it took me some time to realize is that you can slide the leftmost point on the graph to the right (and the rightmost to the left). Often times you want to do this as a first step in using curves - move the lower-left point to the right so as to meet the least-bright pixel you see in the histogram and move the upper-right point to the left so as to meet the brightest pixel you find. This may seem a bit confusing so I've attached a screen capture with these two adjustments applied.
That being said, most of the curve tools I've seen are used to make adjustments to brightness levels. There is a graph that you can think of as plot with the horizontal axis representing light intensity before the adjustment and the vertical axis as representing the light intensity after the adjustment. When the graph itself is a straight line from the lower left to the upper right of the diagram, there is no adjustment - after is the same as before.
You may be offered a variety of ways to distort that straight line - sliders perhaps but often some variation on the idea of clicking at some part of the line and dragging it up or down with the mouse. If you pull up on the left part of the graph you brighten the darker parts of the image while if you pull up on the right side of the graph you brighten the already brightest part of the image. As with most tools on a computer you just need to experiment to get a feeling for what happens. Generally you can find some way to undo what you have done if you don't like the change.
One thing that it took me some time to realize is that you can slide the leftmost point on the graph to the right (and the rightmost to the left). Often times you want to do this as a first step in using curves - move the lower-left point to the right so as to meet the least-bright pixel you see in the histogram and move the upper-right point to the left so as to meet the brightest pixel you find. This may seem a bit confusing so I've attached a screen capture with these two adjustments applied.
May 4, 2015 17:47:07 #
Curves is one of the more versatile and powerful of Photoshop tools and whole books have been written about its powers. One of my common usages is to use the Black, White and Midtone buttons to correct for color casts. This requires one to set values for the white, black and midtone eyedroppers (which can be dine ibside Curves). One place to start would be some of Kelby's books, Photoshop for the Digital Photographer.
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