Curves

[gerardo2068]

Could somebody explain what you can use Curves for? Do you use Curve more than Levels? Do you use a lot of selective Curves? In my own search online I usually find basic explanations about it. The usual is lift the middle to brighten the image, move the sliders in the corners to add contrast, the S-Curves, I find it easier to use level for those type of things. It there a benefit for using Curves instead of level? I have also seen they use the Red, Blue, Green Channels on the curves to make it look like a faded pastel color. What else I should know about Curves? Thank you very much! You advices will be very appreciated. Thanks again

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[gerardo2068]

Any suggestions?

[EchoingWhisper]

Yes, I do use curves very often. I don't even use levels.

[gerardo2068]

I see

[Buckster]

Here's the thing about curves: As you indicated by your many questions, it can do a lot of things. Because of that, it's a very deep subject that is difficult to address in a single post or two. An entire class could be written to explain all there is to know about curves. It can be used to correct and tweak a LOT of stuff.

A lot of folks use it with a simple S curve to pop the contrast a bit globally, or you could go the opposite direction, if you were looking for that effect for some reason. Those tweaks can also be done in individual color channels. Or you can lighten or darken globally. With more knowledge and ability, you can make those kinds of adjustments that are much more specific to areas of the photo, as opposed to global changes. Combined with masks and multiple curves layers, you can have very fine control over so many different aspects of an image's color and contrast that the mind boggles.

Google and YouTube have thousands of tutorials that cover the many subjects related to how to work with and manipulate curves, from the simple S curve to the more complex stuff.

[EchoingWhisper]

Curves is much stronger than levels.

[kylehess10]

I've recently started playing with curves for all of my photos and I do notice a huge difference. You just have to keep playing with them until it looks just right. Some photos need it, others don't. I think it all depends on the look you're going for.

Here's a couple comparison photos, with my first edit in Lightroom 3 and my secondary edit in Photoshop CS5 with curves

[gerardo2068]

I've recently started playing with curves for all of my photos and I do notice a huge difference. You just have to keep playing with them until it looks just right. Some photos need it, others don't. I think it all depends on the look you're going for.

Here's a couple comparison photos, with my first edit in Lightroom 3 and my secondary edit in Photoshop CS5 with curves

Wow. I'm starting today to watch tutorials today!

Thanks everybody for your time. I can see how deep curved can be. I was thinking it would be like levels or other filters and that it had a somewhat specific type of use. But for what I can see there a lot more to it.

[Ysarex]

What else I should know about Curves?

In your post you mentioned the RGB channels so I'm going to assume you're referring to the use of Curves and Levels as applied to RGB photos.

I almost never use Curves on my RGB photos.

Here's what else you should know: If you're sitting in front of an RGB photo and considering using Curves you should first ask yourself these questions:

What did I screw up in the RAW converter that's got me thinking about using Curves now? Shouldn't I go back and get it right before making it worse?

If you're not shooting RAW in the first place then you should ask yourself this question: Why am I considering using Curves on a camera-mangled RGB photo when I could have shot RAW and bypassed this problem in the first place?

After you answer those questions and you still need to use Curves that's fine. But if you're sitting in front of an RGB photo that needs a Curves adjustment the odds are that bad things have already happened to that photo to get it into that state and wouldn't it have been better to avoid those bad things in the first place.

Joe

[gerardo2068]

What else I should know about Curves?

In your post you mentioned the RGB channels so I'm going to assume you're referring to the use of Curves and Levels as applied to RGB photos.

I almost never use Curves on my RGB photos.

Here's what else you should know: If you're sitting in front of an RGB photo and considering using Curves you should first ask yourself these questions:

What did I screw up in the RAW converter that's got me thinking about using Curves now? Shouldn't I go back and get it right before making it worse?

If you're not shooting RAW in the first place then you should ask yourself this question: Why am I considering using Curves on a camera-mangled RGB photo when I could have shot RAW and bypassed this problem in the first place?

After you answer those questions and you still need to use Curves that's fine. But if you're sitting in front of an RGB photo that needs a Curves adjustment the odds are that bad things have already happened to that photo to get it into that state and wouldn't it have been better to avoid those bad things in the first place.

Joe

May be I express my self wrongly or we are not in the same page, but I find your post confusing (I'm new to curves). What I mean by RGB channels is that in the curves panel you can choose to adjust the red, green or blue color independently. So I was asking why I would want to do that? or in which situation I would want to use that?. I see many video they talk about using the Curves tool to improve the photo or sometimes to create a desire effect, like a faded pastel color (like old style photo) So I also wanted to know what other styles can you create with curves. Like in the example photos of kylehess10, The photo of the baseball player was improved a lot by using curves. I went in to youtube and I found a video on curve and it was well explain. Now I think I understand better. I'm not sure what you mean by RGB photo. Thank you for your input!

[Buckster]

What else I should know about Curves?

In your post you mentioned the RGB channels so I'm going to assume you're referring to the use of Curves and Levels as applied to RGB photos.

As opposed to...?

I almost never use Curves on my RGB photos.

What kind of photos do you use them on?

Here's what else you should know: If you're sitting in front of an RGB photo and considering using Curves you should first ask yourself these questions:

What did I screw up in the RAW converter that's got me thinking about using Curves now? Shouldn't I go back and get it right before making it worse?

If you're not shooting RAW in the first place then you should ask yourself this question: Why am I considering using Curves on a camera-mangled RGB photo when I could have shot RAW and bypassed this problem in the first place?

After you answer those questions and you still need to use Curves that's fine. But if you're sitting in front of an RGB photo that needs a Curves adjustment the odds are that bad things have already happened to that photo to get it into that state and wouldn't it have been better to avoid those bad things in the first place.

Joe

At this point, I think you're thoroughly confused, but maybe it's me. If you give a bit more explanation, I'm pretty sure that at least one of us is going to learn something in the process, so please do expound upon your thoughts here.

[KenC]

I agree that one should do most of the global curves adjustments in the raw conversion and that large global adjustments after that point might argue for going back and re-doing the conversion. However, there are always global curves tweaks that need to be done after other adjustments, and also there can be a lot of selective curves adjustment applied only to parts of the image, which really is not possible in raw conversion.

[gerardo2068]

I agree that one should do most of the global curves adjustments in the raw conversion and that large global adjustments after that point might argue for going back and re-doing the conversion. However, there are always global curves tweaks that need to be done after other adjustments, and also there can be a lot of selective curves adjustment applied only to parts of the image, which really is not possible in raw conversion.

If I remember right the curves panel in Lightroom may be a little more limited than the one in photoshop?
Also what about Curves in LR vs ACR?

[Ysarex]

What else I should know about Curves?

In your post you mentioned the RGB channels so I'm going to assume you're referring to the use of Curves and Levels as applied to RGB photos.

As opposed to...?

As opposed to the RAW capture. ACR does have a Curves tool and I do use it. Goal is to get tone response and color right in the RAW to RGB conversion. If you do the RAW to RGB conversion and then you need to use Curves to adjust the tone response, didn't you miss something?

I almost never use Curves on my RGB photos.

What kind of photos do you use them on?

I use Curves to adjust the tone response of my RAW files as part of the process to convert them to RGB. Once they're RGB that job should be done.

Here's what else you should know:...{snip}

At this point, I think you're thoroughly confused, but maybe it's me. If you give a bit more explanation, I'm pretty sure that at least one of us is going to learn something in the process, so please do expound upon your thoughts here.

I'm not confused, but I'll agreee I didn't do too good a job expressing myself.

I know it's common for a lot of photographers to shoot camera RGB photos and then to edit those. So I was saying that's not the way to get the best possible result.

Joe

[Ysarex]

{snip}....and also there can be a lot of selective curves adjustment applied only to parts of the image, which really is not possible in raw conversion.

Basically yes if you live in an Adobe centric world and most of us do (I do use ACR). However what you're describing as local tone adjustments is possible if you use a different converter. Capture 1 is very capable of processing a RAW file via multiple layers and tone and color adjustments applied locally.

Joe