Tutorial on curves?

[pauly99]

Having just upgraded to PS CS and using such features as levels, maybe some slight saturation, a filter, and finally USM, can someone tell me how and where in the workflow to use curves?

[minotauro]

Personally i use curves either as an alternative to levels or as a fine tuning after levels.
With curves you can do some actions you can't with levels, i.e. correcting selected parts of the histogram without affecting the others.
there's a very good example of curves usage in http://www.outbackphoto.com/contest/index.html

[ianmcc]

Bruce Fraser in Realworld Photoshop (THE Pshop book I recomend to everyone) equates Levels to Automatic Transmission and Curves to driving stick. Both will get you there, but the stick shift will provide a bit more control. Once you get used to curves, you won't use levels.

[pauly99]

So, Luigi and Ian.... without taking words out of your mouths, what you are saying is that curves and levels both do the same thing but levels allows a little more tweaking than the former?

I really need to pick up a Photoshop book. Flying by the seat of my pants only goes so far. :rolleyes:

I'll see if the Bruce Fraser Realworld Photoshop book is at the local bookstore.

Thanks a bunch.

[dwbfoto]

I think they mean just the opposite -- curves give a little more control (am I right?).

[sandman]

Curves will allways give more fine control ,it's only a lot more difficult to master properly .
The new version 2 of the ex convertor, is a great way to learn where a certain point of a curve is . click on the photo and you can see where on the histogram it is. from that ,click on the histogram and a point is set on the curve , by moving it in and out you then see the effect on the photo.
It's a lot finer than levels and does take an awfull lot of experiance to use it properly , something i'm sadly lacking in.


Brian

[minotauro]

Yes, curves and levels do similar things and CURVES are more powerful, and more difficult to use.
On photoshop there's a way to bring points on the curves diagram from areas of the image.
Ctrl click on the areas of the image you tink are in need of adjustment, their location will be marked by a point on the curve that can be dragged.
I do recommend the reading of the curves workflow contest in digital outback...

[pauly99]

oops. I'm sorry. I mistyped. I now realize that curves will give you more control over the image. I'll play around with EX and Photoshop CS to see the differences when making changes via curves.

[jknights]

Yes, I tend to do an AutoLevels then tweak with Levels. I have just learnt this by trial and error so I dont know if this is the best way.

There are a few occasions when the colour balance is just way off and I really struggle, so I guess a Voegeli lesson would not go amiss.

Tom are you out there.?

[Claude Ollieuz]

About curves:
http://www.gurusnetwork.com/tutorials/photoshop/curves1.html

[pauly99]

Claude, thank you. That gives me a better understanding of curves. I like where you can locate values on the curve (a particular point on an image) and then manipulate according
to that specific point. :cool:

[pauly99]

My original image complete with dust on the CCD.

[pauly99]

and my image after cleaning the dust off (via Photoshop), using curves and a tad bit of oversaturation.

[ianmcc]

nice job on the curves!

For us <ahem> old time photographers, the curves dialog reminds me of plotting denistometer readings, and looking at the kodak data sheets of old comparing different emulsions!... But for someone who doesn't have that background I agree they are intimidating! Practise makes perfect, took me a while to feel comfortable using them. That Cmd click trick is handy to get plots of areas you want to tweak. And always make it an adjustment layer, so you can redo it over and over til your happy. While it's open, holding the OPT button changes the Cancel to Reset, a quick way to start over!!

Hard to believe, but Bruce Fraser also recomends color correction with that dialog! That's too tuff for me, I revert to the color balance dialog

Not to sound like a groupie but Bruce Fraser is the man!... I got hooked on his explanations of photoshop stuff at Creative Pro

Search for him here:
http://www.creativepro.com/front/home

Then pick up the Realworld Photoshop book. If you're in a real production enviroment, turning in files for eventual publication, this is a great book.

[jknights]

Nice job pauly.

[RacerX]

Looks like I need to learn another PS tool. Awesome pic Pauly!
I love the blue sky you pulled out against the light house colors really stand out. Hey, how about a tutorial on using curves?
If not, I'll settle for a good link tutorial. :D

Thanks . . .
Rick

[pauly99]

Rick, thanks for the compliment. I'm finding that using curves is taking over levels in Photoshop for me. Thanks to the links from Claude and Luigi and some good time (lots of time) playing around I found that the lighthouse image changed dramatically. I'm finding that if even there is lack of time or sheer laziness on my part, auto curves can make a quick good looking adjustment for you. I'm at the beginning stage of learning curves. Hopefully someone that has had plenty of practice could provide a tutorial.
Otherwise there are plenty of great folks out here to offer help or to point to some useful links.

http://www.creativepro.com/story/feature/18118-1.html

[RacerX]

Thanks for the link. I'll be off reading for awhile and testing to learn the old fashion way, hard work. :) Thanks Pauly

Rick

[seanmcclain]

Wow! That's pretty impressive pauly. Either you're a real natural or the curves dialogue has more applications than I thought. Probably a little of both. Thanks to all for the good links and tips. The ctrl-click command really is a great tip!