Levels vs Curves vs Sliders

Discussion in 'Digital Photography' started by VirtualRain, Mar 5, 2015.

  1. VirtualRain macrumors 603

    VirtualRain

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    Aug 1, 2008
    Location:
    Vancouver, BC
    #1
    I'm curious, what tools do you guys go to first or most often to correct an image that is either under-exposed or lacking contrast...

    1. Levels? (which is a histogram style tool in Aperture and C1 - sliders for blacks and whites in LR)

    2. Curves? (another histogram style tool)

    3. Exposure Sliders? (exposure, contrast, highlights and shadows)

    Why?

    I have to admit that I always found wrestling with curves to be a bit of a challenge. It was very difficult to get good results. And to be honest, I don't think I ever really used levels either. My tendency was to adjust with the normal exposure sliders.

    Have I been missing out?
     
  2. paolo- macrumors 6502a

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    Aug 24, 2008
    #2
    I tend to go for the curves adjustment layer. I find it gives you ultimate control in a single tool. I find the exposure sliders decent when importing a RAW file. But I dislike that you can't move the midpoint of your contrast. You also can't move your white and black points. And obviously you can't tone an image as you can with the RGB curves.

    I find the important part of working with a curve adjustment is to control the adjustment opacity. The curves control aren't too precise, so make the window big and consider lowering the opacity for a pleasing result. Also, don't shy away from using multiple curves on top of each other instead of trying to do everything in one.
     
  3. The Bad Guy macrumors 6502a

    The Bad Guy

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    #3
    This. ^ I use curves adjustment layers all the time.

    As a matter of fact, that last image I posted (Photo of the day thread) has no less than six curves adjustment layers all doing different things at different opacities, with different blend modes and multiple layer masks.

    Levels are okay to get blacks and whites, but curves are just way more versatile.
     
  4. VirtualRain thread starter macrumors 603

    VirtualRain

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    #4
    What app are you guys using for this?

    My problem with curves is that they aren't granular enough... they're always impacting other regions of the histogram in an unwanted or negative way which is why I feel like "wrestling" is the right term for that control. Do different layers and opacity help? Can you give me an example of an image and walk me through what you would do to it?
     
  5. The Bad Guy, Mar 6, 2015
    Last edited: Mar 6, 2015

    The Bad Guy macrumors 6502a

    The Bad Guy

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    #5
    Photoshop. This is a good explanation if you're interested in how it works (hipster alert).

    https://www.youtube.com/watch?v=tRX4ormVWEg

    Edit: The histogram.
    I see far too many people getting hung up about it. Obviously the stuff I do is a little different to most around here, but I don't let the histogram bother me too much at all. Some times I want to blow those highlights out, crush that black to death etc. Histogram is just a rough guide for me to manipulate the **** out of. :D
     
  6. JDDavis macrumors 65816

    JDDavis

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    Jan 16, 2009
    #6
    Hey VR, if you don't want to go the Photoshop route keep working the local adjustments in C1 Pro and you can gain more control over different parts of the image. Photoshop is the end all be all for this kind of stuff but it's just too much for me. I'm no curves expert (the C1 Pro tutorial helps) but I use them in C1 Pro for adjusting the histogram to where I want it in regards to the global effect on the image and then I use the mask tools in C1 to adjust specific layers. You don't get to use curves and levels with the local adjustment tool but you get exposure, HDR, Clarity, Structure, and others. It's not as powerful as Photoshop can be but you can gain similar control while staying native in C1.

    For example, in a landscape shot I may be a little dark below the horizon and the sky may be a little to bright (typical without using a filter). I'll make some global adjustments to the image to get the exposure to a happy medium and then I could use the gradient mask tool in C1 to continue editing the sky and earth parts separately (2 masks). Or I could use the global tools to expose correctly for one part of the image and then use a mask in the local adjustments tool to bring the other part back into my chosen exposure. I also like using the masks to add or take away clarity which kind of acts like sharpening or blurring parts of the image.
     
  7. FredT2 macrumors 6502

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    Mar 18, 2009
    #7
    In Lightroom, adjustment sliders 99% of the time, because I find that I can get what I need from them without resorting to the curves.
     
  8. MCAsan macrumors 601

    MCAsan

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    #8
    I use a import preset in LR that does many things, including setting the Tone Curve to medium contrast, bumps up Clarity, ...etc. After the image is imported, I can easily adjust the image using other Presets, specific sliders, or take the image to Perfect Photo Suite where I can do all manner of adjustments in a stack of layers and blend accordingly

    Presets in LR, or Perfect Photo Suite, can save you a ton of time! Don't reinvent the wheel every time there is a new image to edit.
     
  9. Bending Pixels macrumors 65816

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    Jul 22, 2010
    #9
    Which application are you using/referring to? Many image editing app's have these features. Knowing which specific app you're referring to would help.
     
  10. MCAsan macrumors 601

    MCAsan

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    #10
    Exactly. All the major DAM apps (Aperture, Lightroom, Capture One Pro) and lots of editors have the needed features.
     
  11. VirtualRain thread starter macrumors 603

    VirtualRain

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    #11
    I know Aperture, Lightroom, and C1 all have the curves, levels, and sliders controls, I'm just wondering which ones you go to for fixing an under exposed image or one with low contrast?

    I use to just up the exposure and contrast using the basic sliders. But lately, these levels and curves tools are staring me in the face, and I'm wondering if I should be using them. :)

    ----------

    Yeah, I'm not interested in using Photoshop... but all the major apps have Levels, Curves, and then the basic sliders... so I want to understand who uses what, when.

    As I said earlier, I find curves extremely frustrating... Am I the only one?
     
  12. paolo- macrumors 6502a

    Joined:
    Aug 24, 2008
    #12
    I'm using it in photoshop. Here's an example I was just working on. It's actually a render not a picture but pixels are pixels...

    First is a composite. There are actually 12 layers under there that were blends of different lighting, there's a few curves adjustment layers in there as well.

    The first curve is has some toning and contrast. I added some yellows to the midtones and contrast around the low midtones in the concrete. This layer was brought down to 66% opacity. Then I added a curve to brighten the whole image but preferentially the highlights. I liked what it was doing but it wasn't enough so I duplicated that layer and lowered the opacity to 75% on the clone.

    This is a mild example but in both cases, brightness and contrast alone wouldn't have been enough as I wanted to target a specific tonal range.

    If you find you're impacting other parts of the region, add points on the transverse line to make the adjustment on a specific tonal range. Also consider using blend-if in blending options. This will allow you to taper the adjustment off the highlights or deep shadows. Don't shy away from using layer masks either. I do my dodge and burn on curves layers. Finally, I find it easier to exaggerate what I want and then lower the opacity as the curves control can be finicky. Also, don't try to do too much with each layer as it quickly becomes to hard to manage. I rarely have more than 3 points on a curve.

    Obviously this depends on your style. Curves are especially useful when doing large post processing in photoshop. I actually hate using it in Lightroom...
     

    Attached Files:

  13. JDDavis macrumors 65816

    JDDavis

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    Jan 16, 2009
    #13
    Have you tried playing with the Curve Point Picker in C1 Pro yet? It's the little icon in the curves tool window on the bottom right. If you click it and then select an area on your image it will create a control point on the curve where that tonal value is. You can then drag it around and see the effect it has on the image. I do this to help focus on specific areas of the image I want to effect. In the end I don't believe C1 Pro can do anything like the masking functions in Photoshop (other than the local adjustments, of course). If you want that level of control (12 layers with different curves) you have to go to PS. Edit...You can build as many layers as you want in C1 Pro with local adjustments you just don't get the curves or levels tool.

    For me, if I got the exposure pretty close in the camera then I generally don't mess with curves or levels that much. Usually the sliders are all I need. I'm usually aiming to replicate what I saw with my eye or slightly enhanced beyond that. I'll go more dramatic with black and white but that's why I like SilverFX. If the histogram is way off (usually too dark) then I'll use curves and levels more. I'm finding I used them more in Aperture than in C1 though. I thought Auto Curves in Aperture actually worked pretty well most of the time.
     
  14. Bending Pixels macrumors 65816

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    #14
    Well...since you didn't really say which app you're referring to....I'm using Lightroom, which doesn't include Levels. Most of my editing is done using the Basic (highlight/shadow/exposure, etc.) sliders, sometimes use the HSL/Color/B&W sliders to adjust specific colors. Rarely do I use Curves.
     
  15. VirtualRain thread starter macrumors 603

    VirtualRain

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    #15
    Thanks, but I'm not using Photoshop and not about to start. It sounds like from the few folks who use Curves, you use them in Photoshop and on multiple layers... RAW editors have one and only one curves adjustment for the whole image... how would you use that?

    Now, I realize this may be insulting, so I apologize for my ignorance here, but it's just my observation... the last image looks like it just had a small exposure boost over the others. Did it really require 12 layers of curve adjustments to achieve that result? :eek:

    Thanks... I didn't know about the Curve Point Picker... I'll check that out. Maybe it will help me wrestle curves to the mat! :D

    Last night I was playing with the Levels tool in C1... which is pretty similar to the adjustment of the same name in Aperture if I recall correctly (which I never used). I don't think LR has this tool, but it does have blacks and whites which I think are part of it. I found Levels to be a better solution to correcting underexposed images or low contrast images than simply adjusting the exposure and contrast sliders. It seemed to result in better contrast. I could also adjust the highlights of just the blue channel to adjust the tone/saturation of the sky which was cool. Does anyone else use sliders?

    ----------

    Yeah, this was my methodology in Aperture as well. So you don't use the Blacks or Whites sliders at all? (I think that's the equivalent of Levels)
     
  16. paolo- macrumors 6502a

    Joined:
    Aug 24, 2008
    #16
    No worries, maybe I just wasn't clear it wasn't actually 12 layers of curve adjustments :p lol The first image was a composite of 12 layers of content. I then added the two curves layer globally which I showed you in each subsequent image. It's a bit of the nature of rendering. It's hard to get everything right in a single image so you render out multiple passes with different lighting and materials and composite them together. There were a few curves adjustments I did on individual elements in there too. Luckily it's a fairly fast process as the rendering engine gives you an image with the selections already cut out and some of the layers in the composite don't have much going on in them either.

    Though I agree with you. Curves are more powerful in Photoshop than in a DAM/RAW editor. I still use it from time to time but mainly for grading with the RGB curves. But without the power of adjustment layers I also find them really frustrating.
     
  17. VirtualRain thread starter macrumors 603

    VirtualRain

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    #17
    I see... makes sense. Maybe the key to curves is opacity and masks. As a global adjustment, they seem to be too unwieldy.
     
  18. VirtualRain, Mar 6, 2015
    Last edited: Mar 7, 2015

    VirtualRain thread starter macrumors 603

    VirtualRain

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    #18
    So I have an image here... It's the Notre Dame in Paris. It's largely under exposed (don't ask me what it was metering :rolleyes:)

    I just used normal sliders to adjust it. I increase exposure significantly, pulled the shadows ever further, and then recovered the highlights to compensate. I also did color editing on the sky to make it darker and bluer and the vines to make them less olive and more green. Then cropped it square.

    Is there a better way to do this with Levels or Curves?

    If anyone wants to take a run at this... the RAW file is here...
    https://www.dropbox.com/s/n5q7n49hnfghfcf/5DM32683.CR2?dl=0

    Before:

    [​IMG]5DM32683 by Virtual.Rain, on Flickr

    After:

    [​IMG]Notre Dame by Chris-VirtualRain, on Flickr
     
  19. The Bad Guy macrumors 6502a

    The Bad Guy

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    #19
    Probably about 15 minutes worth of tinkering about. :cool:
     

    Attached Files:

  20. VirtualRain, Mar 7, 2015
    Last edited: Mar 7, 2015

    VirtualRain thread starter macrumors 603

    VirtualRain

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    Aug 1, 2008
    Location:
    Vancouver, BC
    #20
    Interesting... thanks. Can you share what the settings/curve looks like for the building/wall?

    EDIT: Would it be possible to get anything close to this result using just one curve tool as a global adjustment?

    BTW, I need to tone down my sky... LOL... it looks a bit neon! :( (Done!)
     
  21. The Bad Guy macrumors 6502a

    The Bad Guy

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    Australia
    #21
    1. Nope. I've since deleted the TIFF. Sorry.
    2. Nope.
    3. You sure do. What were you thinking? :p
     

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