You know, the odd way I learned to use PS shows. I learned it from reading Dan's Professional Photoshop. And one thing he hates is levels. He's a downright snob about it, and I guess I caught the disease from him.
By way of making sure I what you're doing here, is this conceptually similar to "pushing in the ends" to the edges of the histogram in a levels adjustment layer?
Tom K. wrote:
I am curious as too how much sharpening you did to the final large image.
No sharpening at all in the interest of not complicating the lesson. It looks sharper because it has good contrast. Now if you go ahead and sharpen it carefully, it will look even better. But you'll need a light hand. Grass like that has a lot of fine detail and contrast and is easy to oversharpen. Might try the light/dark halos technique.
Tom K. wrote:
I took another image and gave it a go. In fact I have been going through image after image and applying the techniques in this thread. The fact that I'm color blind saps some of my confidence because in reality I just don't know whether the colors are accurate or not. My eyes lie to me. I have an image here that I wanted to get the contrast in the sky much more pronounced than I ended up with. It's the L channel that I believe is making me ineffective on this shot. If I may be so bold I am posting a link to the original photo and the downsized final image I finished with. I really wanted to improve the contrast in the overcast sky. I just couldn't figure out how to do it. Unfortunately I forgot to do screen caps of the curves I applied in a b and L channels.
I still have a lot to learn. Book should be incoming next week.
BTW, where was that picture taken. Looks so familiar.
I've just read the tutorial for curve work & working with LAB colour & just had a couple of queries. I work as a designer & use photoshop CS2 everyday. I work mainly in CMYK or RGB if certain effects such as lens flare or whatever are being used. How do the comments for adjusting curves in LAB apply to CMYK or RGB? I normally adjust curves directly in CMYK, ususally on an adjustment layer. Should I change everything to LAB & then change back to CMYK? If so, how does the continual converting affect the final image for print?
Thank you Rutt for your time and the wonderful tutorial, it makes some sense now.
I do have a dumb question. Is there anyway to have the a & b boxes up on your monitor at the same time? Or is there some reason they shouldn't be
Don't think it is possible, unfortunately.
Would be nice, though. Just like being able to adjust the a & b curves symmetrically in one go - I'd like to see that possible.
Well, maybe not perfect.. but much better than the original posted on the whipping post.
Give yourself a pat on the back for being adventurous!
I just applied the basic recipe to your original, with 10% steepening of the A and B curves. My L curve looks a lot different than yours. I found a good shadow near the crotch of the guy on the viewer's right. What I didn't find was a good highlight. The lightest thing I found was the brightest patch of the arm of the second guy from the viewer's right. So I moved the light endpoint of the L curve toward the center so it was just to the left of this point. I added a bit of steepness through the mid tones with those two interior points. I didn't sharpen, as that's not really the issue here.
I didn't follow your description of your LAB curves. A picture is worth a thousand words; perhaps you could post a screen shot of the curves you are talking about.
And once you have the image in LAB, why not sharpen the L channel there?
Anyway, this image has a complexity which makes the simplest LAB recipe not work quite right. Those reds are very magenta, almost out of gamut as it is. So just blindly steepening the A curve won't work here.
Next I'd steepen just the B curve and not the A curve for this one because of that extereme magenta.
Give yourself a pat on the back for being adventurous! But, please, can you explain what your were trying to do when you varied the basic recipe and how the curves you wrote achieved it?
Note: My favorite way to compare before/afters like this is to load them both into photohop and copy one into a layer of the other. Then you just click on the layer eyeball to toggle back and forth and you'll see them in place. If this tip doesn't make sense, speak up and I'll go into detail.
Anyway, I don't mean to discourage experimentation. In fact you have skipped ahead a couple or 10 chapters here. But you should learn to crawl before you run with this one. Get the basic recipe just as I described it in the tutorial to work for you first and then start working through the more subsequent chapters and more advanced techniques here: http://www.dgrin.com/showthread.php?t=18203
First, I'd like to point out that the original posting for this image is in aRGB so that's one reason why it looks so washed out in all non-color-aware browsers. Just moving it to sRGB helps quite a bit.
I did basically the same thing as Rutt (followed the basic chapter 1 LAB color enhancement recipe of pusing in the A and B curves 10% symmetrically on each end), but I added the following things afterwards (just because this is a fun image to play with and learn from):
A steeper L-curve, but used blend-if and curve shape to keep from making the blown highlight areas worse.
A small amount of shadow correction in shadow highlights to bring a little detail back in the darker parts of the blue jeans.
A separate A-curve for just the faces (using a mask) to pull some magenta out of the faces while not affecting the arms.
Slightly brightened the faces with an L-curve on the same face mask.
Fixed blown highlights on the arms with both the impossible color fix and a little cloning
Tried to fix some of the blown highlights on the shoulders (though I was less successful here)
No sharpening added.
I must admit though, I prefer the faces a little magenta... this day was a (very rare) hot, hot, day, and these guys were really going for it. Like a row of grunting beetroot!
Yeah that rule about yellow and magenta balance in faces,