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LAB Color correction and Sharpening in Photoshop

February 14, 2020


Hello everybody welcome to a new
tutorial with PSD box I’m Andrei and it’s been a long time
since I published my last free tutorial here on YouTube and on my website and
truth is that I had some problems with my website some personal problems as
well and I couldn’t publish new tutorials or
even read my emails so I apologize for that I’m back into business the premium
websites and everything is now under one website which is psdbox.com because
people had lots of problems switching websites and I understand
it now everything is into one place and problem solved. Okay let’s go with
today’s tutorial. What I want to show you today is how to use the LAB color mode
to make color Corrections on an image and also how to create selective
sharpening in Photoshop. Of course what I’m going to show you today can be
done in different ways and also may be in RGB color space but I want to show
you how you can do it in the LAB color mode. So I got this image from
unsplash.com you can see I have the link over here if
you’re watching this from YouTube you will find the link on the video
description if you want to use exactly the same image but you can use any image
this is just for demonstration purpose it works on any image and if you’re
watching this from the website you’ll find the link on the web page as well. So,
let’s get started with this we’re going to start with the sharpening because if we
start with the color correction and then we sharpen the image, if you want to make
any kind of change on the color correction we have to throw away the
sharpening make the correction and then sharpen it again. So we’re going to start
work on the sharpening So the first thing we want to do is go
to Image>Mode and choose LAB color You will see that nothing happens a set that
flicker of their which indicates that Photoshop switched to LAB color space
the image is exactly the same but the only changes that you will see is for
example here on the blend modes menu you will see that some of the blend modes
are not available in this color space which is normal. Also if you go to
channels you will see that instead of having RGB for red green and blue we
have Lightness, we have Channel a and Channel B we’re going to talk about what
each of these layers mean a little later on when we’re going to make the color
correction but first let’s work on the sharpening as I said. So select the LAB
channel which is a composite select any of the selection tools I used the
rectangular marquee tool press Ctrl or Command+A to select the entire canvas
and go to edit copy merged the press Shift+Command+C or Shift+Ctrl+C on a PC
this will copy the whole thing now have to create a new channel by clicking this
new channel icon and we’re gonna paste that here with Control+V or Command+V
You will see that it’s going to paste it on black and white which is normal because
alpha channels do not have color information or at least it’s not gonna
show it on color in color so here what we have is an equivalent in black and
white of each of the colors that we have here on the LAB layer
You’re going to see that is not the same as the lightness. Okay, so if you
choose Lightness and then go to alpha 1 you will see that alpha 1 is darker
because here the only thing that we did is just convert those colors into black
and white while the Lightness only holds information about the light and shadows
not the color so it’s not a color conversion it’s just light information
Okay now have alpha 1 and this is the layer that we’re going to use to sharpen
our image we’re going to go to filter sharpen sorry stylize and choose fine
edges as I said we’re gonna sharpen the edges of the image but not
only the edges because you can see that we have some of the dark bits there as
well these dark parts of the image will be the ones that will be sharpened we’re
going to convert this into a mask so everything that is black will be the
parts that are…that will be selected and sharpened so not really a mask because
on a mask the white parts gets the effect that we are applying in this case
it’s the opposite. Now we want a little more contrast so I’m going to press
Control/Command+M to open the Curves and I’m going to move
the black point somewhere around here the more you move it to the right the
more black area you get and that means more of the image will be sharpened if
you only want to sharpen the edges you should move the white point as well to
this to the left and you can see that now we got rid of all the black bits in
between and only the highest contrast bits of the image are selected. We don’t
want to have that it’s too extreme so I’m going to put this somewhere around
there and the black somewhere around here now this depends on each image because
each image has its own contrast and it works like that, so I’m going to have it
somewhere there because I want inner parts of image to be selected to be
sharpened as well so not only the edges cuts going to look weird okay, so I’m gonna
press Ok and now because some parts of the edges are too sharp the transition
between black and white is too sharp I want to blur that slightly because if
I if I’m to sharpen this it’s gonna have a really sharp effect over here and then
we have a really more unsharpened effect here so the transition is not gonna be
really that good so I’m gonna go to Filter Blur and I’m going to choose the
Gaussian blur now we don’t need much of a
a blur here just one pixel you can see that one or if you have a really high
resolution image maybe two but not more than that something like we just
softened a little bit the edges remember this is not going to affect how sharp the
image is going to be the sharpening has nothing to do with this blur this is
just the transition between the sharpen area and the less sharp areas of the
image okay I don’t know if I explain myself but you’re going to see that in just
a second. Now we have this later ready I’m going to double-click here to change
the name and I’m going to name this edges press ENTER and I’m going to select the LAB channel to go back to the composite and go back to layers now this channel has
is there alone we’re going to use it right now I’m going to create a copy of my image
and I’m going to name this Sharp. With Ctrl/Command+J you can create copies
and now I’m going to go to SelectSharpen and I’m going to choose…
I usually like to use the Unsharp mask but you can
use any of the filters here make sure you go to 100% by pressing Command+1 or
Control+1 on your keyboard to see the image on the real size. Threshold, we’re
going to set it to zero because we already have our areas well selected and
the radius really depends on the size of your image. If you go too high you’re
going to start to see halos and really strange stuff which we don’t want about
1 for this canvas size and of course the amount really depends on your image
Try to just move around the image with the with the space bar you can click and
well look through the image to see how the image gets sharpened. I like this
area over here to assess my sharpening effect because we have highlights we
have shadows we have small details around here have medium details we have
edges so it’s a good point to assess our effect. I’m going to increase the
amount a little more and probably the radius slightly more. I don’t know if you
can see it on the video but if i deactivate and reactivate it you can see
how the effect looks like. It’s harder on the edges because that’s what we wanted
but we also sharpen the inner parts of the of the objects as you can see right
over here on these areas take a look ok now I’m going to click OK, and we’re done
with the sharpening. Let’s move on with the color correction. For that I’m going to
use a Curves adjustment. You can use Levels as well and since I have my
selection active I forgot to deselect by pressing Ctrl/Command+D I’m going to fill
this with white because I know I don’t need the mask here. Here on the Curves
you will see that we have exactly the same channels Lightness A and B. Now what’s
the a and what’s the B? Channel a contains information for red and green
and in fact if you move this line down you will see that you
green on the image if you move it up you add red or magenta. Actually I think it’s
cyan and magenta. And on the B we have blue and we have yellow. And this is all
we need to remove color casts from our image. Now let’s start with the a. The
difficult part here is judging what kind of color cast your image has. Now I think
there are more advanced ways of analysing your image but for this
tutorial I’m just gonna do it by eye I don’t know if you can use this these
eyedropper tools to kind of change how the image gets corrected. I like to use
it I like to make this manually I know this has some yellow cast on it because I
see it here on the whites. Actually you can I think you can use the information
already from window if you go to… if you check the info here from the window
choose info and when you move across an image you will start to see the image
here on CMYK. For example yellow you see have a big deal of yellow 20% 38% and
it’s kind of too much. But let’s do it the easy way. Let’s go to the B channel
because we need to take away some yellow, so I’m going to drag
this down a little. And actually I’m going to do it more on the whites than on
the shadows. I’m going to drag this down like so and probably leave this about
there. A little more right over there and on
the a channel you can add a little more green on some parts of the image, maybe
over there a little more red over there, back to
the B. Probably add more blue to the shadows really quickly just to show you
how you can tweak the images here. On the Lightness channel what you can do
is increase the lightness, actually the contrast of the image
without affecting the colors because we have no color information on this
channel. So you can darken the image you can increase the contrast a little.
Like so. Okay and that’s pretty much it that’s the color correction. Really quick
really basic it’s not something that’s really advanced but you can correct your
images like this. Now let me show you how the image looked without using the
curves. Before and after… we have more contrast and you can see that yellow
here on the white parts and the overall image is now gone. Also, the greens are
looking more green now not that yellowish, and that’s how it looks
like. Let me show the original image. This is what we started with and this is what
we have I’m going to zoom it and 100% so you can also see the sharpening, for
example in this area before and after I think it looks way better. Especially
over here. Take a look at this area as well before and after
okay? So this is how you can use the LAB color mode to make color corrections
and sharpening your images. I hope you liked this tutorial if you did if it’s
the first time you see my channel make sure to subscribe and also visit my
website PSD box comm you have lots of Photoshop tutorials there you have
playlists you have resources and all kinds of design stuff there that you may
like. So thanks for watching and see you next time

3 Comments

  • Reply rick b February 7, 2020 at 12:50 pm

    Great video!

  • Reply Marco Calia February 7, 2020 at 8:09 pm

    Bel video by Italia 🇮🇹

  • Reply Luis Ricardo Oyola Díaz February 8, 2020 at 11:00 pm

    Por qué no lo hicieron también en español como los de antes? 🙁

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