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Registered: 01-2011
Location: Doncaster South Yorkshire
Posts: 728
Contrast Curves


I was recently teaching an online Photoshop workshop and it suddenly struck me that not everyone is comfortable with contrast curves.

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The first image is simply a NULL based linear curve and this type of curve will have no effect on the underlying image

The second image shows a typical S shaped contrast curve where most of the contrast will effect the 1/4 shadows all the way through to the 3/4 highlights. We know this because of the steep linear shape to the curve between these points.

The third image however shows a somewhat different story.

If we applied this curve to the image then we are going to achieve a great deal of contrast through the mid-tones all the way to the upper 3/4 of the highlights but the shadow areas would suffer from a decrease in contrast.

The reason why the shadow area would suffer is because of the way the curve flattens out in the 3/3 shadow area.

When applying curves as the chosen adjustment, try to prevent the curve from flattening out unless you are deliberately wanting to remove tone and contrast.





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19/Feb/15, 12:26 pm Link to this post Send Email to IanBarber   Send PM to IanBarber
 
Digital Finger Profile
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Re: Contrast Curves


brings up the question for me... does it make any difference whether you use levels or curves if you wanted to drken shadows-to get teh same effect in each? I expect exactly the same thing happens to teh fie in practice - non?

I also imagine that using the hsitory brush technique might get you round this problem, or not?

Last edited by Digital Finger, 20/Feb/15, 1:23 pm


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20/Feb/15, 1:22 pm Link to this post Send Email to Digital Finger   Send PM to Digital Finger Blog
 
IanBarber Profile
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Re: Contrast Curves


quote:

Digital Finger wrote:

brings up the question for me... does it make any difference whether you use levels or curves if you wanted to drken shadows? I expect exactly the same thing happens to teh fie in practice - non?



You can use Levels to increase / decrease contrast as well and lightening or darkening but unlike using curves you are unable to see the shape of the curve you have created



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Photoshop Panels - Actions - eBooks and more..
http://www.digitalblackandwhite.co.uk

Personal Website
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20/Feb/15, 1:24 pm Link to this post Send Email to IanBarber   Send PM to IanBarber
 




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