Question on "Curves"

[JZaun]

I keep reading about adjusting curves. I thought, don't ask a dumb question eventually you will read what this is. :? Well I still haven't seen it :D . I have PSE2 and can't find any info. Is this something I need to know and use. I keep trying to do better in PS in order to go to raw but so far I do better with Jpeg. Is curves part of the answer?

Thanks

JZaun

[PhotosGuy]

I'm not sure just what info you're looking for here, but try Googling for [curves tutorial "Photoshop Elements"] without the []
You'l get 877 hits.

Here's one link:
Curves, Levels, or Contrast/Brightness?
http://www.arraich.com/ps6_tips_ccontrast1.htm

[Scottes]

Is curves part of the answer?

Curves are powerful but not always the answer. They allow changes in specific regions of color, separated or all at once. They are quite powerful, but can be a tad overwhelming for someone like me who can't see tiny differences in color, and they can be tricky to use. I have used them, but not often, so someone with much more experience with curves will tell you that they are the cat's meow.

If the problem is:
"The reds are too bright in the high end, but fine in dark and middle, and my greens are too weak in the dark end, need to be a touch dimmer at the high end, and the blues are perfect."

Curves are the answer to this problem (but probably not the only answer).


Rather than worrying about a feature, though, I'd worry about a problem you have. There are often many solutions to a particular problem.

[PacAce]

Jerry, unless you're planning on upgrading to Photoshop, I wouldn't worry too much about curves since it's not available with Elements. It can be a useful tool, though, if you had it.

[eric1]

curves gone wrong!
http://www.pbase.com/image/27965216.jpg
eric1

[eric1]

i find the best argument for raw is the control you have over exposure
and white balance. if you don't get the exposure right on, it's easy to adjust 2 full stops either way in C1Rebel. saved many a photo for me.
if you try that with a JPG file it is much harder, with all the masks you have to make. plus C1Rebel is fairly cheap.www.pictureflow.com

thanks,
eric

[Idoc]

Curves I have found coupled with levels can lead to some of the best results I have ever achieved. Levels does wonders but Curves really packs a punch getting tones, contrast, and other aspects correct looking.

It can go very wrong and is one of the more touchy and hard to understand techniques within PS (in my opinion). It's worth it to learn it, but be ready for many frustrated hours.

[BDM]

Jerry, unless you're planning on upgrading to Photoshop, I wouldn't worry too much about curves since it's not available with Elements. It can be a useful tool, though, if you had it.

You are right except that curves for Elements 2 are available by installing the CD which comes with The Hidden Power of Photoshop Elements 2 by Richard Lynch. There are a number of other neat aditions available too.

Bruce

[bikerider]

as idoc says, curves coupled with levels is quite powerful.......don't know if elements has channel mixer (ps7) but i've found adding this really sorts out colour correction.

[Jesper]

as idoc says, curves coupled with levels is quite powerful.......don't know if elements has channel mixer (ps7) but i've found adding this really sorts out colour correction.

PS Elements does not have Curves and also no channels, so no channel mixer.

Or rather, these things are present in PS Elements, but they are hidden in the user-interface. When you install the tools from the book The Hidden Power of Photoshop Elements 2 (http://www.amazon.com/exec/obidos/tg/detail/-/0782141781/qid=1082109492/sr=8-1/ref=sr_8_xs_ap_i1_xgl14/002-0076724-3541634?v=glance&s=books&n=507846) you can use Curves in PS Elements.

[CyberDyneSystems]

"Curves" is one of the oddest tools in PS.

There seems to be little to help you understand what the changes are doing.. those I know in the graphics design industry that rely on the curves adjustment a lot seem to have an intuitive sense of how to use the tool,.

Myself,. I can't get the hang of it.

I rely on the levels tool exclusively for now,. untill I can finally make heads or tails of what it is I am doing with curves..

I think part of the reason there is so little instruction/discussion is that no one really knows how to explian it.. :) lol


//another baffled individual :)

[Bytes U]

OK you guys will love this link, it helped me understand the use of curves. There is also a bunch of other photography lessons available at this site.

Petteri's Photo Lessons- Main Page (http://www.seittipaja.fi/data/Photography_lessons/a_Photography_lessons.html)

Direct link for Petteri's curves lesson (http://www.seittipaja.fi/data/Photography_lessons/Processing/Lesson_4/_Curves.html)...

[Roger_Cavanagh]

There an excellent explanation of curves in the first link in this section (http://www.rogercavanagh.com/links/links-01.htm#Adobe%20Photoshop).

Regards,

[stopbath]

Curves tool is quite simple in fact but difficult to explain.

The curves tool is remodeling how the pixels transgress from deep to bright. Usually they would step up by one level of brightness for each neighbor. So if you start at pure black (zero) and look at the next bright pixel, it will have a value of one, the next will have a value of two and so one until the last pixel value is 255 (after 255 steps). This does NOT mean that any pixel actually exists in the image of that value, but if one or more did, the value of it would now be changed once you click on OK.

Now as you move the line, you modify how the pixel values relate to the neighbors... Instead of 1 to 1 relationship, you can bow the line so that at the black end things progress really slowly, (1, 1, 1, 1, 2, 2, ...) and at the white end of things they progress quickly (..., 220, 225, 240, 245, 250, 255)

You can make various progressions to achieve various effects. Usually a modest application is all that is needed.

If you grab the line in the middle, you will modify the mid tones. If you grab the line at the top, it's the brights you modify. The bottom modifies the darks. If you move the dark straight up, and the brights straight down, you create a negative... The more flat the line, the more flat the image...

Of all the tools, I think curves is my most used...

[CyberDyneSystems]

Thjanks for these links,. it semi confirmed my intuition that both "curves" and "levels" are two seperate interfaces to take control of the same aspects of the image.. however what I did not realize is that with curves there is the ability to isolate the adjustments made more precisely...


...onve you have a "clue" how to use curves that is :wink:

I think these tutorials will get me well on my way!

Thanks.

[Scottes]

I've been futzing with Photoshop just about 1992, but as a hobbiest. So I've never really tried curves - because every time I do something goes haywire.

This may be difficult to explain with pictures but I know one of you PS gurus can explain it...


On one of my butterfly pictures the butterfly was a very bright orange. All the other colors seemed perfect except that the butterfly literally glowed orange. I wanted to reduce the orange "glow" back down to just orange without modifying anything else (or barely).

So I went into curves, choose the Red channel, and clicked on the line about 3/4 the way to the top. I didn't move the line, I just wanted to "anchor" it at that point. Then I clicked about halfway between that dot and the very top - so now I'm about 7/8ths the way to the top. I moved that dot down a bit, which bowed the entire line - limited somewhat by my anchor point. So I stuck another dot about 1/2 way up and moved the line back to where it belonged, thus creating 2 "anchors."

So now my Red curve was barely bowed along it's length, and somewhat bowed down in the top quarter.

The picture looked like crap. I was really expecting it to only modify my brighter reds, but I started seeing red fringes all over the place.

Was I on the right track to reducing that orange glow? Should I have selected the butterfly to limit the change (which would have been a PITA...). I ended up mucking with the R G & B channels which got pretty close, but it wasn't what I really wanted.


Any hints or tips?

[Idoc]

Scottes: I would like to try if you wouldn't mind posting the image. As CDS said before it is somewhat intuitive. I have learned some adjustments and can most of the time get the results I intend. I can't explain the process really but could note my steps through this image to show my work. I believe another fellow "Garethhhhh" is somewhat useful when it comes to curves also. I like these image correction challenges you have come up with, very intriguing :wink: