curves question

[Pauline]

Okay, got my new book (Creative photoshop lighting techniques) and I LOVE it. Now there is a section on curves where you go and change each channel separately to decrease or increase the amount of each colour. The curves that we have doesn't have this ability and I wondered if using the coloour balance in Grant's tools instead would be the same idea??

[Wendy]

Pauline ...

Well I never noticed that before ...

Actually adjusting colour with curves is pretty tricky so I would tend to use one of the other functions such as Colour Mixer or Colour Balance.


Wendy

[Pauline]

Okay, what would be the difference between using those two and using hue/saturation? Or is this just another --- 3 ways to do things?

[Wendy]

Pauline ...

Hue and Sat changes the colours just as one change but Colour Mixer lets you mix the individual colours ... its a much more complex thing.

If you use H&S then you couldn't just add a little more red ... its quite difficult to explain. Best thing to do it try out the colour mixer and just see how much more control it gives you ... you just can't get that sort of control with a Hue & Sat layer ...

Wendy

[Pauline]

Thanks Wendy!! This book has opened up a whole new world and so far I'm loving it. I have done some colour theory with my painting, so perhaps it won't be too difficult. I have a feeling I'll be very busy on here tomorrow!

[Carbone]

Pauline,

H&S adjust the luminosity values of every pixel. You can either make the colour more vivid (more saturated), more or less bright (until everything is white or bright) or even shift colour.

If you look at the Hue and Saturation dialog, you'll see two bars of colours at the bottom. If you adjust the Hue slider to the left or the right, you'll actually shift the colour of every pixels on your image. For example, if you slide hue to the right, then what's green will become blue. You can also select a specific Edit channel to adjust only one colour. But sill, you'll play on the luminosity (saturation, lightness).

Channel mixer let's you mix the colours, change them on the individual channel. You can reduce the amount of green, or blue, or red, but only this channel. Of course, it's not exactly pure.

Because each pixel is composed of 3 values (Red, Green and Blue), decreasing Red may push your colour towards the green, for example. Channel mixer will help when difficult colour correction is required.

Also, you don't actually change the luminosity of the pixels, only their colour values.

Contrary to many others, curves and I don't agree. We don't play well together. I prefer Levels and Channels rather then Curves.

Ray

[Pauline]

Thanks Ray. I'm going to try and digest this tomorrow morning with fresh eyes and some experimenting, which is really the only way to understand. Boy, I'm going to have a busy day tomorrow!! :lol:

[Wendy]

Ray ...

Curves just take a bit of getting used to ... you need time to play with the feature to get used to it :) :)


Wendy

[Carbone]

Wendy,

No hard feelings intended.. I just entirely share Jay Arraich's views on the subject :

http://www.arraich.com/ps8_CurvesCommentary1.htm

Ray

[Wendy]

Ray ...

I agree with him on Shadows/Highlight but not curves :) :)

I love curves http://www.millan.net/minimations/smileys/inlove2.gif (http://www.millan.net) and find the ability to make subtle changes with it is wonderful ... and Wow can you get some great effect with strange setting http://www.millan.net/minimations/smileys/electricf.gif (http://www.millan.net)


:lol: :lol: :lol:

Wendy

[Pauline]

This is all very interesting, and I just read the article. One thing that I have learned through my art is a lot of times people do things as they "think' they look not actually the way they look. Your mind perceives it one way and in actual fact it's not correct. It's hard for me to explain exactly what I'm getting at. There is a a book called "drawing from the right side of the brain" (never did work completely through it). In the exercises we had to draw a picture of a man sitting in a chair. The picture was up side down and we had to draw it looking at it that way. Because the mind didn't really recognize it as a man in a chair because it was upside down, you were forced to draw the shapes you saw not what you 'thought' you saw. It was amazing how accurate my drawing turned out when I flipped it around and compared it with the flipped version in the book. My 3 kids also did this exercise (they would have been I believe around 7, 9 & 11 then) Theirs was also very accurate.

And then of course there is the fact that we have the ability to manipulate the image to make it high key or low key. This debate I guess could be endless as to how much manipulation is correct and whether we're talking reality or art. I thank you both for the information, and I'm looking forward to spending more time with my book today! (up late last night and up early this morning! I'm anxious to get going!)

[Carbone]

Pauline,

I read the same exact book !!! It's a wonderful book for he or she thinks they're a lost cause at drawing. It's not very expensive (20$ I think), but it's worth every penny. And for anyone who don't use English as their primary language, that book as been translated (in French at least).

I, too, sometimes look at pictures and tell myself "I think they've overdone it", especially in sharpening and luminance (too saturated, too bright, too contrasted).

I remember back, in the film glory days, a subject would be clear without being absolutely sharp. And it was still considered a super shot! Lighting subtleties has also gone with the arrival of digital cameras because of the sensors' inhability to perceive the various shades of light (except, maybe, for the high end cameras).

Ray

[Pauline]

Ray, I believe you might be interested in "creative photoshop lighting techniques" by Barry Huggins. I got it yesterday and I'm thoroughly enjoying it!! My only complaint is that it doesn't come with a cd of the photos to practice on.

I'll also leave you with a wonderful quote from Freeman Patterson that I read this morning that sums it up perfectly. "The photographer must struggle to keep his own preconceptions from obscuring the truth." Which is a much more eloquent way of saying what I was trying to say earlier!!
The best way to learn is by really seeing and figuring out what is pleasing and WHY. I don't think there really is a right and wrong. It's all in the eyes of the beholder, as they say.

So now it's off to lessons!

[Carbone]

Pauline,

It says it all, indeed !

What is the book you got ? I did a search on Amazon.ca and came up with 4 different revisions... If you could point me towards the one you got, I'll ask Santa to include it in my xmas list :)

Ray

[Pauline]

Okay Ray. First off you don't want the newest one (I don't think it's out yet, but it's for CS2). The one I got is the older version. It has a blue cover, and there is a woman in red with a window shadow reflected on her in the top left. --The newer version has a close up of a face here). It's published by Lark books --we discovered that the brown cover one is the UK version. The press date is 2004.

Here's the link

http://www.amazon.ca/exec/obidos/ASIN/1579907601/qid=1131126896/sr=1-12/ref=sr_1_2_12/702-7295451-4684068

I also have his "Surreal digital photography" and love it. It's not for everyone, but I love turning things into unusual creations. That's where the eyeball in the rose idea came from.

[Carbone]

Thank you, thank you, thank you !!! :-D

Ray

[aandres]

Here's a link to some curves info from a very enthusiastic user.
http://www.thegoldenmean.com/technique/curves1.html
I'll also drop this into the Helpful Links forum.

Ariel

[Wendy]

Hi ...

Thanks for the link. It looks a very useful site :)


Wendy