PS LAB Color, Chapter 16 -- Recipe for portraits

[rutt]

This chapter presents a recipe for portraits which Dan claims drastically improves their belivability. The recipe is easy to learn but it has a few decision points which I've found difficult to master. I've been practicing it for a few months now and also practiced in Dan's class. Now I'm getting consistently improved portraits, though I still make mistakes. Dan demonstrated with about 5 or 6 images in class and competed with his students on another 4 or five images and his results were consistently fantastic. Even if you follow the steps exactly as Dan presents them, the whole recipe can be applied in a minute or so, once you get the hang of it. I've introduced some automation which replaces a few of the repetitive steps and makes it even simpler to do.

The basic recipe:

1. Remove any cast. Dan says to do this in RGB, but really you can use your preferred method, good raw conversion, RGB curves, LAB curves, whatever. At the end of this step, your fleshtones should be warm, positive both A and B. (At least as much yellow as magenta.) The rule that B should be at least as positive as A is only a rule of thumb. Rosy cheeks, sunburn, makeup, cold wet days, sunset light, can all lead to exceptions. But in principle, it's good to find at least some flesh where this is true, perhaps on the neck. For darker complexioned people, the balance will tend to favor yellow and for lighter complexioned people it will tend toward balance with more magenta than yellow in the rosy cheeks, etc. Balancing on a known neutral area, perhaps a white shirt or grey hair often works. Important:Don't worry if you desaturate a bit at this point. As long as the fleshtones are warm, the recipe will add plenty of saturation soon.
   
2. Improve definition, depth, and sharpness by using the green channel as a luminosity blend. Examine the each of the red, green, and blue channels indivitually. Which is the better B&W version of the portrait? Usually the green channel is best by far and much better than a naive conversion to grey scale. So just use it for luminosity.
   
   Here's an easy way to make a luminosity blend from the green channel. Create a duplicate layer and select it. Image->Apply Image, and select the green channel of the current image. Change blending mode to luminosity.
   
   If your image has dark reds or purples, you'll have a problem at this point because they will be black in the green channel. Use blending options to exclude them from the blend.
   
   There's lots more to say about this step. Suffice to say, if you are good a B&W conversions, you'll get the best results by making the best B&W conversion and using it for the blend instead of the green channel.
   
3. Convert to LAB and flatten. Note the order.
   
4. Increase color saturation and variation Create a new layer and overlay blend it's A channel to itself and B channel to itself, varying the opacity of the blends for different complexions. This is one of the key decison points of the technique and the place I've had the most trouble. Dan rule of thumb is (a) fair skin, blue eyes, blonde hair: maybe 80% A opacity and 100% B opacity; (b) Dark skinned race: maybe 100% A opacity and 80% B opacity; (c) Else, equal (100%) opacity for the overlay blends.
   
   Dan's way of doing this is to use Image->Apply Image for each of the A and B channels with overlay mode selected and vary the opacity. I have an alternative which I think is a little easier to use unless you are Dan and have a lot of practice with the technique. See below.
   
5. Dial in the level of saturation and color variation introduced in the last step with the opacity slider for the new layer. Obviously, this is also one of the key decision points, but it's lots easier than the step above since you can just use your eyes to see what looks best to you.
6. Attempt an L curve move on the reduced opacity layer to increase contrast and establish better white and dark points. Because the layer has reduced opacity, it isn't possible to blow the highlights or plug the shadows by doing this, so it may be an easy way to get better facial detail. Don't try too hard. Often no move is fine or the best curve is a simple 3/4 tone bump.
7. Sharpen the L channel, usually both conventional sharpening, but avoiding flesh, and high radius sharpening.
8. Optionally, convert through RGB to CMYK and establish a deep rich shadow without plugging by steepening the K curve.

We need to discuss the decision point at step 4.

Prroably this seems like quite a lot of work, but, as I said, I have some automation which can help and it does go very fast once you get the hang of it. First I'll introduce the automation and then I'll walk though the process with an actual image.

The automation is a Photoshop action which replaces steps 2-4. Well actually it replaces steps 2, 3, and about half of 4. You still need to make the decision of how much A overlay vs B overlay to use. You can pick up my action here. It's a set containing two actions:

• Dan Margulis Portrait
• DM Swap AB

Once you have an image in RGB without a cast, use the Dan Margulis Portrait action. You'll end up with a LAB mode image with three layers. The topmost layer is "A overlay" and is just what it sounds like, the A channel overlayed with itself. The middle layer is the same thing for the B channel. And the original (after the green channel luminosity blend) is the bottome layer. At this point you can adjust the relative amount of yellow vs magenta overlay with the opacity sliders of the overlay layers. For Caucasians you'll probably want to lower the opacity of the A overlay layer or do nothing. Use the color sampler to chek the A/B balance of your image. Remember, you are trying to make sure that the basic skin tone has at least as much yellow (positive B) as magenta (positive A). Remember, this isn't iron clad. There will be some spots that don't obey: rosy cheeks and sunburn for example. Makeup is a huge stumbling block. For women, a spot on the neck or back of the hands is the best guide. If you need to lower yellow relative to magenta that is lower the opacity of the B overlay layer, perhaps for non-Caucasian individuals, use the action Swap AB first which will put the B overlay layer on top and adjust the blending modes accordingly. (If you can't figure this out, we can discuss at length.)

Once you get the balance right, you just merge down the top two layers and proceede with the recipe at step 5.

Warning: My action doesn't leave room for the blending options adjustment in step 2. This is something I'd like to improve and probably either I will or someone will eventually.

[i]Edit: Changed the link above to reflect a new more permanent location. Also the new action set contains a green luminosity => LAB action. I'll post a little more about it at the bottom of this thread.

Step by step example

OK, enough words, time for some action! Let's walk through the recipe with a portrait of mine, selected in part because it's easy. Here is the original:


Full size

If you actually look at the indivdual channels of this, there is a good case for the blue instead of the green channel as the best B&W version. The eyes are very drammatic, but it would bring out the freckles in a big way. A careful blend of the green and blue channels would probably yield the best result here, but for now we'll just follow the recipe blindly. In fact, I just ran my Dan Margulis Portrait Photoshop action:



and ended up with this LAB image:


Full size

At this point the layer palette looks like this:



OK at this point, some real by the numbers analysis is called for. The image is way too saturated, but is the color balance right. Your eyes won't tell you, but the Color Sampler tool will. I checked a number of places on her face and found that the there was as much yellow as magenta nearly everywhere on her face except those pink cheeks and lips. This girl just ran a cross country race, so you'd expect some pink in her face. Anyway, typical values are:

• Between the eyes: A=22, B=27
• Tip of the nose: A=21, B=29
• Neck in sunlight: A=21, B=30
• Freckle: A=46, B=52
• Rosy cheek in sunlight: A=43, B=31
• Reddest, darkest part of the cheek in shadow: A=28, B=0

This seems about right. When I frist started to use this technique the temptation was strong to enforce the B>=A rule throught the face, but that's a mistake which will result in too much yellow in places. These values are good and in this case, Dan's prediction that a dark haired Caucasian would want equal A and B channel overlay opacity works out.

So now we merge the top two layers and join the recipe at step 5. I played with the opacity slider of the top layer and arrived at this:


Original size

by using a 56% opacity on the overlay blend layer:



We are now at step 6 of the recipe, which calls for possible application of an L curve to enhance contrast. This image doesn't have a true highlight, I don't want to take that reflection on her forhead all the way to white or an impossible color; but the left eyelashes have a place that should be a true shadow. I used this L curve (still on the reduced opacity overlay layer) to open up the contrast:



And arrived here:


Full size

At this point I flattened in preparation for sharpening. This is a slight divergence from Dan's recipe in that he sharpens on the lowered opacity layer. I find this confusing, perhaps because I'm used to sharpening according to my own habbits. If you haven't already, you may want to read my basic USM tutorial here.

First I used conventional L channel USM sharpening on the L channel to bring out the gleam in her eyes, to make the eyelashes and eyebrows sharp. Since she is such a young healthy girl, I didn't have to worry about confining sharpening her skin. I'm sure this issue will come up with other examples and those who've been keeping up will be able to think of lots of ways to manage it. But for this image it was no problem. Here are the sharpening parameters:



and here is the result:


Full size

The final step is HIgh RAdius LOw AMount (HIRALOAM) sharpening (also on the L channel, very very important.) This takes a little practice, but it's a great thing to know how to do. Use the Unsharp Mask filter on the L channel and start out with the Amount slider set to 500 (all the way up.) and the Threshold slider set to 0 (all the way down.) Bring the Radius slider to 10 and keep increasing it until the large facial features (cheek bones, chin, eye sockets) are outlined. Too far and the face will start to go white. To little and you won't get the outlines. The right radius is very dependent on the image. Closer crops and higher resolution calls for higher radius. I've used values anywhere between 10 and 100 recently. For this image I settled on a radius of about 66:



At this point, don't expect the image to look good:


Full size

But you can see that is emphasizing the overall shape of here face by outlining the cheeks, chin, eyes.

Next, lower the Amount slider, until the obvious sharpening artifact become invisible. Start with 50 and try values ranging from about 40 to about 65. In this case I settled on 48:



with this result:


Full size

This will still look a little too harsh, but there are no obvious visible sharpening halos. Use the preview check box often while you do this to see how you are doing.

The final step is to soften the effect of HIRALOAM sharpening by raising the Threshold slider a bit. HIRALOAM sharpening is very sensitive to threshold, so be careful here. Too much and you'll lose the effect. Too little and it will look harsh. I settled on 6:



and here is the final state of my portrait:


Full size

Please compare it to the original and see what you think.

[rutt]

Practice Plan
I've been thinking about how to practice this technique. I've been practicing it for more than a month and had Dan's personal help, and I still don't feel that I've mastered it. Clearly, it's worth mastering, and once mastered it cleary can make a huge difference, especially for prints. Also, once mastered, it is very quick and easy. I've seen that in action. I believe that working as a group and providing each other feedback can greatly speed the process of mastering portrait post processing.

There are sereral places where important decisions go into the recipe:

1. Choosing the plate for the luminosity blend
2. Getting the color balance right
3. Deciding how much of the overlay blend to use
4. Choosing the radius for the HIRALOAM sharpening

As the scene becomes more complicated, other issues also enter in.

So, anyway, I've been thinking that instead of having everyone work on his/her own images, we'd do something different. In his classes, Dan has everyone work on the same set of images for an hour or so and then the entire class looks at the results together and tries to pick a winner. Sometimes there is a tie, which is a good thing as it shows that everyone has learned.

What I'd like to do here is emulate that process the best we can given the difference between live and a web BB. I'll pick a few images from the ones people are posting here: http://www.dgrin.com/showthread.php?t=22505 At first I'll make the decisions based on pedagogical issues -- some images are easier and some illustrate different issues. If there is anough interest and we keep at this for a while, other people can pick images to work on or we can figure out a process of some sort. I think it would be nice if the photographers considered it an honor to have their pictures chosen.

We'll all do our best with them. When you are done, don't post your results directly but rather send them to me. I think it improves the lesson if we don't share until we are all done. Once we are done, I'll post the results and we can try to come to a consensus about which ones work best.

There will actually be a prize for the winners: big, beautiful, delux prints of your versions of the portraits. I'll print myself and send to you and to the photographer. I don't do this lightly and Andy, Pathfinder, or Ginger can tell you that my prints are very nice.

Anybody want to play this game?

[DavidTO]

Originally Posted by rutt

Anybody want to play this game?

Sure.

[warszawski]

Originally Posted by rutt

Practice Plan
Anybody want to play this game?

yes, i am ready to follow your idea, so if i understand well, i can pick-up (?) one of existing pics and try to put it in the workflow described in CHapter16 of DAN Margulis book and send you the result, I would like to start with RAW file(s) , is it possible ?

[rutt]

Hold your horses for now. Sometime very soon I'll post a handfull of shots for the first assignment together with the best orignals I can find (raw if possible.)

[ziggy53]

Originally Posted by rutt

Practice Plan
Anybody want to play this game?

I would love to play, but I only have access to PS7. Is the process compatible to PS7 or is there anyone that would care to translate the process to PS7 compatible, or as close as possible? (HIRALOAM sharpening, for instance?)

Thanks,

ziggy53

[rutt]

Originally Posted by ziggy53

I would love to play, but I only have access to PS7. Is the process compatible to PS7 or is there anyone that would care to translate the process to PS7 compatible, or as close as possible? (HIRALOAM sharpening, for instance?)

Thanks,

ziggy53

There really is nothing in the basic recipe that can't be done in PS7. PS/CS has the shadow/highlight adjustment which can help some portraits a lot. PS/CS2 has surface blur which is really good for older women's skin. And for raw conversion with modern cameras, you need PS/CS2. If you need raw conversions, I'll provide them, so that won't be a problem. The other two issues might come up or not. They won't come up in most of the images so you can play on a level playing field most of the time.

[aporia]

Originally Posted by rutt

Anybody want to play this game?

I'm game. With head still spinning from reading the summaries over the last few weeks, I'm ready to jump in and give it a go. I've started to read Margulis this week and look forward to learning more about color theory and L*A*B* processing.

Thanks, Rutt, and others here for a great discussion thread.


Tom

[rutt]

Here is another example of what this technique does:



I accomplished this with a process very similar to the step-by-step I posted for the portrait of the young girl.

I still don't have enough of the right kind of shots for a first set of practice shots, but I'm hoping that I will soon.

I'm going to post a few more step-by-step examples in the meantime which illustrate some other issues. Stay tuned.

[warszawski]

original comes from Awais Yaqub http://www.dgrin.com/showpost.php?p=198141&postcount=12

recipe:
1) in RGB : New Layer ; Apply Image with channel "blue" ; mode=luminosity & opacity=50%
2) go to Lab : New Layer ; Apply Image with channel "a" ; mode=overlay & opacity=50%
3) paint on noise highlight with mode=color & blend mode IF top layer (select some interval of luminance)
4) go to RGB : stamp layers; duplicate layer ; filter high pass with mode= soft light; opacity 70%
5) in option: remove shadow on the left part of portrait

[rutt]

Another stepy-by-step

The point of this step by step is to illustrate the problem that can be caused by bright red or purple objects and a solution.

I started with this original:


Full size

1. Remove any cast. I checked for a cast here. This kid does have a ruddy complexion, not to mention some teenage skin problems. But when I measure on his neck and just to his left of his left eye, I get plausible balance measures: A=12, B=21 on the neck and A=15, B=20 near the eye, wouldn't want that any more yellow. Furthermore, the white on his shirt is reasonalby A neutral, leading me to believe that the color really is OK to start with here.

2. Improve definition, depth, and sharpness by a luminosity blend with the best channel. Here are the red, green, and blue channels of the original:


Full size

And here is what happens if I just use Image->Mode->Grayscale:


Full size

Which is the best B&W? The red channel and the naive conversion are nonstarters. I suppose we could make a case for the blue channel. But, as expected, the green channel is best, with better eye detail and less skin problems.

So I made a duplicate layer and used Image->Apply Image with 100% opacity and normal blending to apply the geen channel to the composite of the duplicate layer. At this point the image is B&W and looks just like the green channel since it has been applied to all three channels and they are now equal. But after I changed the blending mode to Luminosity, the image looks like this:


Full size

Click the eyeball for the luminosity blend layer on and off and see the effect. Looks pretty good on the face, eh? But not so good on the red cap and shirt. They are way too dark now. Why? Look at that green channel. Not much green in that black shirt or cap. And green is no being used as a luminosity layer.

We could attack this while still in RGB, but as we are on our into LAB, there is a better option. I converted the image to LAB, this time using Edit->Convert To Profile:



The luminosity blend does work better in LAB; the impossible dark colors are working in our favor:


Full size

Still, that cap and shirt are much too dark. (Use that eyeball again to compare the image with and without the green layer luminosity blend.)

The solution? Anyone who has been following along, especially chapter 8, should be ready to try blending options as a potential quick fix. In this case the quick fix is also a perfect fix. I used the Blend if sliders for the A channel to exclude the most magenta areas of the background layer from the blend:



And then I fine tuned with the L channel sliders to exclude the very darkest areas of the upper (green channel) layer from the blend:



Notice I didn't even have to split the sliders for this particular move. In this particular image, that red is so distinct that the sliders can describe it perfectly. See:


Full size

Now we have the good contrast and definition on the face from the green channel and have recoverd the original color of the shirt and cap. Looks good. Flatten and proceed.

At this point I added a variation. I wanted to be able to see deeper into those eyes. They are just too dark. A very careful use of shadow/highlight on the LAB layer seemed to help a lot:




Full size

This is the only thing from this example that can't be done in PS7 (or 6 for all I know.)

4. Increase color saturation and variation At this point I could have done it the way Dan actually does it:

1. Make a duplicate layer
2. Image->Apply Image of it's A channel to itself in overlay mode
3. Image->Apply Image of it's B channel to itself in overlay mode

Instead, I used my new Dan Margulis Portrait Action Set
Run the action 2. Make overlay layers to get to this point:




Full size

Dial in the level of saturation and color variation Of course this is way too much makeup for a kid who is already pretty bright in the first place. I merged the two top layers and played with the opacity to get this:




Full size

At this point be sure to use the eyeball to turn the layer visibility on and off. Does it really look better? Is something else wrong?

To me, it really does look better. This kid isn't that healthy looking to begin with, but this does make him look better. But there is a problem. The overlay has pushed parts of that shirt way out into the magenta startosphere. This could be easily fixed with some sort of a A curve, but even easier is to use blending options again, to tone down the very most positive A overlay blend:




Full size

This time I did have to split the sliders to prevent obvious transition lines between the blended and unblended areas.

Try for better use of contrast with an L curve on the reduced opacity layer At this point the image is still a little dark. There really is no proper white point, but the lightest parts of his face could be a lot lighter without looking blown, resulting a more open look because we'll use our contrast budget better.




Full size

This is one time you don't really have to worry about blowing highlights or plugging shadows with an L curve because it's being aapplied to a layer with reduced opacity. Check the numbers in the info pallette with the color sampler to make sure.

Sharpen Conventional USM sharpening brought out a nice gleam in the eye, some fine facial detail including peach fuzz on his chin, and some stitching in his hat and shift.




Full size

The final step is high radius low amount sharpening. Make sure the L channel is selected (but all channels are visible), set Amount to 500, Threshold to 0 and play with the Radius slider to look for a setting the emphasizes the major facial features, chin, cheek bones, eye sockets, forhead, the shape of the face. This is a closeup and a 8 MP image, so I ended up with a pretty high radius:



But I've had a little practice by now, and I can see this will do the job by looking at the (very ugly) image.



Being able to tell what it's going to do is one of the advantages of this method over the low pass filter.

At this pont I dialed back USM Amount to all but hide the huge halos and turned up the Theshold just a bit to make it less harsh.



Voila!


Full size

[jfriend]

Originally Posted by rutt

Another step-by-step

I started with this original:


Voila!

Very impressive result and an excellent writeup! Thank you for doing this. I'm amazed by the fine detail that comes out in the face and eyes and even the baseball cap.

[DavidTO]

Originally Posted by jfriend

Very impressive result and an excellent writeup! Thank you for doing this. I'm amazed by the fine detail that comes out in the face and eyes and even the baseball cap.

Yep. It's not a glamour treatment, that's for sure! My wife, for one, would not be happy if I posted a portrait of her with that much detail. Having said that, the reworked image has an immediacy that is just not present in the first. Great job, Rutt. Can't wait to play with it.

[Nikolai]

Originally Posted by rutt

Another stepy-by-step

This post and the whole thread is awesome! Thank you very much!

[rutt]

Originally Posted by DavidTO

Yep. It's not a glamour treatment, that's for sure! My wife, for one, would not be happy if I posted a portrait of her with that much detail. Having said that, the reworked image has an immediacy that is just not present in the first. Great job, Rutt. Can't wait to play with it.

We are going to do some glamour as well as harshness. The recipe has so many knobs that you can get what you want. The first step by step subject I posted is quite flattered by the technique. Or see:





Maybe I'll do one that flatters this kid. That wasn't my goal with this particular shot, but could be done. Hmm.

But a big part of the point of practicing this together is to learn how to use it properly. It's very easy to make a mess and my idea is that we can all help each other develop better judgement in application of this thechnique. I know I still feel I need this.

[rutt]

The images for the first practice set are now available. See: http://rutt.smugmug.com/gallery/975802

I added a few more images in order to get slightly better variation of gender, age, race, &etc. Not enough males, though. Next set, I hope we'll address that.

OK, here's the protocol. Please follow as closely as possible. I believe we'll all learn more if we do it this way.

1. Work with the best input possible. The gallery above allows downloading "Originals". Use them. If you don't know how, PM me and I'll help you.
2. In some cases, the RAW versions are available. In those cases, I've done my own raw conversion and explained what I did in the portrait caption. If you want the raw version, PM or email me and I'll arrange for you to get it. I don't think you'll need it, but I'm wiling to learn.
3. Do not crop. Do not resize. That will make it much harder to compare results.
4. Ditto, no healing brush or cloning for now. These things are best done last anyway. I will give one or more examples to show some flattering non-local techniques for aging skin and blemishes.
5. When you are done, save your finished work as a full sized highest quality possible jpeg. Do not reduce the size. Remember, I've promised very large prints to the photographers and to the best retouchers of each shot. This will work much better if we keep the quality and resolution high.
6. I've arranged the shots in what I think is a reasonable order, with what I think will be easier shots first. I might not be exactly right, but if we all do stick to it, we'll be able to evaluate the first batch of corrections sooner.
7. When you start to work on a shot, add a comment to it on the gallery page. When you are done, add another comment. That way I'll know when everyone is done. If you have a smugmug account, upload a full sized original to a private gallery there and send me an PM or email with the location. If you don't have a way of hosting a full sized original, let me know and we'll work it out.
8. I'm going to work on these shots, too, because I also want to refine my technique. The more people participate, the more we'll learn from each other.
9. When all the versions of a particular shot are done, we'll work together to decide which is the best version(s). In Dan's classes, I found this consensus judging process very instructive. I'll lead the process in that I'll set the format and moderate the process, but I wont' be the judge. The more input we get while we do this, the better our decisions will be.
10. If any questions, technical or otherwise, while you are working, please don't hesitate to ask them. The best way to do that is just to post here. If the question is technical, show your work so that others can learn as well.

[ginger_55]

OK, I can't get the first page to print out, I have no idea why, and I am almost out of ink.

ginger (I click on the one, it should be available to print then, shouldn't it?)

[rutt]

Originally Posted by ginger_55

OK, I can't get the first page to print out, I have no idea why, and I am almost out of ink.

ginger (I click on the one, it should be available to print then, shouldn't it?)

What is it exactly that you are trying to do and that isn't working? The gallery or my posts?

[ginger_55]

Originally Posted by rutt

What is it exactly that you are trying to do and that isn't working? The gallery or my posts?

I was trying to print your posts, so I could have them in my lap while I worked.

I got it printed, finally, to Step by Step example, then my printer went bonkers.

I am not an expert on this printer.........at all. It is a small cheap HP, I think, printer.

I am going to wait til bill gets home, or until I feel well enough to get the book and see if I can figure something out of that. I do not want a large size print of any photo that I gave you. Please, give it to someone else.

I do want to do a print of my grandson to give it to him for Christmas, I posted that photo on this forum. But as I understand, I am supposed to do these. I really do need this stuff printed out, don't know what is wrong here.

ginger

[rutt]

Originally Posted by DavidTO

Yep. It's not a glamour treatment, that's for sure! My wife, for one, would not be happy if I posted a portrait of her with that much detail. Having said that, the reworked image has an immediacy that is just not present in the first. Great job, Rutt. Can't wait to play with it.

I could have been a lot kinder to this poor kid, but frankly, that's not what I was going for here, nor what I was trying to illustrate. The practice set contains lots of examples that will need kinder treatments. Just to show it could be done, though, I went back and gave this kid a kinder treatment. Here's the original side by side with the kinder correction:


Full size

What did I do differently?

1. His skin is so bad, that the green lumonisoty blend brings out a lot of impperfections. I spread the blending options slider wider in the B channel wo some of his face was blended at less than 100% opacity.
2. Before the overlay blends, I used Surface Blur on a duplicate layer, to smooth some of his skin imperfections. Then I adjusted the blending options, to restrict the blur to skin only.
3. For both conventional and USM sharpening, I loaded an inverted L channel as a selection to sharpen more in the darkest parts of the image and less elsewhere.
4. When I was all done, I blending back the original at 30%. This is a favorite trick of Dan's. Keep the original around and use it to turn down all your great stuff, which sometimes looks better while you are doing it than afterwards.

I'm going to do two more step-by-steps before starting on the practice set myself. I want to show what I can do with an older person and also with a non-caucasian.