From color to grayscale

It probably looked less like Ansel Adams, and more like Anson Williams (the guy who played Potsre on Happy Days, which I'm told is a TV show that aired long before I was born, seeing as though I'm just 17 years old. which doesn't really explain how I came up with the chapter title "Back in Black" from AC/DC, which is another band that I guess my parents used to listen to. Freaks). Anyway, Photoshop has a number of different ways to convert from color to black-and-white that can give you dramatically better results than Photoshop's default conversion, which., .well., .emits a pungent odor not unlike a dachshund that dined on a leftover chaiupa. Which method is right for ycu7 Try them and find otic which one suits your style,

Using the Lightness Channel

This method of converting an RGB image to grayscale lets you isolate just the luminosity in the photo, separating out the color; and by doing so, you often end up with a pretty good grayscale image. However, because this uses the Lightness channel, we also add one little twist that lets you "dial in" a perfect grayscale photo almost every time.

Step One:

Open the color photo that you want to convert to grayscale using the Lightness method.

Step Two:

Go under the Image menu, under Mode, and choose Lab Color to convert your RGB photo into Lab Color mode. You won't see a visual difference between the RGB photo and the Lab Color photo— the difference is in the channels that make up your color photo (as you'll see in a moment).

Mode

B «map

Adjustments

Ouoton«

Duplicate...

Indexed Color .

Apply Image.. Calculations...

✓ RGB Color CMYK Color

image Size . Canvas Size...

Lab Color

Multichannel

Rotate Canvas

✓ 8 Bus/Channel

Crap

16 Bits/Channel

Rrvrj' AJ

CuUrr 1db>e

Histogram...

Assign Profile... Convert to Profile .

Trap

0

0

Channels

g

9

m

i*t

X-

9

Lightness

XI

[•

*

U2

9

b

X3

Go to the Channels palette and you'll see that your photo is no longer made up of a Red a Green, and a Blue channel. Instead, the luminosity (the Lightness channel) has been separated from the color data, which now resides in two channels named "a" and "b" (as shown here).

Iiwimw Itti

Iiwimw Itti

Step Four:

We're interested in the grayscale image that appears in the Lightness channel, so dick on the Lightness channel in the Channels palette to make it active (your photo will now look grayscale onscreen as it displays the current active channel).

Adobe Photoshop

Discard other channels?

Step Five:

Now, go under the Image menu, under Mode, and choose Grayscale. Photoshop will ask if you want to discard the other channels. Click OK. You'll notice that you now only have a Gray channel in the Channels palette.

Continued

The Photoshop Book tor Digital Photographers

Step Six:

Co to the Layers palette, click on the Background layer, and then press Command-J (PC: Control-)) to duplicate the Background layer. Switch the Blend Mode of this duplicated layer to Multiply, and you'll see the photo become much darker on screen.

y -

1 Ootan |ioo» p

ChuU

Oma)

K

1 .y»# 1 Q

Oe**

IM« lt#»

LeMai Screw*

uu D0091

0>q*»>

icf Lqnt

MrtL»**

V^UjW

lawarup«

tm ogr«

.J rP: 9

----.. '

Chances are, changing that top layer to Multiply (which has a multiplying effect) made your photo too dark. This is where you get to "dial in" your ideal tone. Just lower the Opacity for this layer in the Layers palette until you have the tonal balance you've been looking for.

^ilflMttlittLfcl

Step Eight:

Here's the final conversion from color to grayscale. This method gives you much more control, and depth, than just choosing Grayscale mode from the Image menu.

2SX(Uytr 1. Cray)

2SX(Uytr 1. Cray)

Custom Grayscale Using Channel Mixer

This has become the favorite of many professionals (and some will argue that this is the absolute best way to create grayscale photos from color photos) because it lets you blend together all three RGB channels to create a custom grayscale image, and it's easier to use (and more intuitive) than using the Calculations feature that I'll show you later in this chapter. Here's how it works:

Step One:

Open the color photo you want to convert to grayscale.

Step Two:

Choose Channel Mixer from the Adjustment Layers pop-up menu at the bor.tom of the Layers palette (as shown here). Channel Mixer is also found under the Image menu, under Adjustments; however, by choosing it as an Adjustment Layer, you have the added flexibility of being able to edit your grayscale conversion later in your creative process, or to change your mind altogether and instantly return to a full-color photo.

tnluj Cnlot C'Aduenl..

Layers

i

Piilrrn

z

i

». I ;

Curv«l Co'o« ftaUrx« ftnqtitncit.Centrist.

m #

9 J

Setefli»« C«tO«.

Criil'tni Uip %

Iflv«rt ThrnhoJd foiittut

Iflv«rt ThrnhoJd foiittut

ft

*

* ♦ M __

Channel Mixer

Output Channel Cray

«

H

Source Channels

* Cancel

Red

• 100

%

f load-

Creer

To

]%

Ö Prev»ew

)

Blue

ö

%

Coniunt

0

|x

^Monochrome

■P

By default, the Channel Mixer is set to blend color RGB channels. When you're using this tool to create a grayscale image, you have to turn on the Monochrome checkbox at the bottom of the dialog to enable the blending of these channels as grayscale.

Output Channel Gray

Source Channel* Red:

Output Channel Gray

Source Channel* Red:

Creen

--—*r

.40 *

Blue

1 •

[Ö i*

Constant

—+-

<

Cancel

: toad...

(

Save...

Mi Previr

Monochroei e

Channel Miner Output Channel Cray

Source Oannelt Red |*60 f«

Creen

Constant

Monochrome

Step Four:

Now that you're blending the channels as grayscale, you can use the three sliders to combine percentages of each channel to create your grayscale photo. When blending channels, a rule of thumb is to make sure that whatever your percentages are, they add up to a total of no more than 100% (as shown here).

Step Five:

You can tweak the overall brightness of your grayscale image using the Constant slider at the bottom of the dialog

Continued

Step Six:

Click OK and the Channel Mixer is applied to your photo to create a grayscale image.

Step Seven:

After you've clicked OK, if you decide you want to edit your Channel Mixer settings, just double click on the Channel Mixer layer in your Layers palette (as shown here) and the Channel Mixer dialog will appear with rhe last settings you applied to your photo. If you decide that you don't want your photo to be grayscale at all. just cliek-and-drag the Channel Mixer Adjustment Layer onto the Trash icon at the bottom of the Layers palette.

Ourr-el M-er

Output Chumi Cray touru Channel* ■tod

Output Chumi Cray touru Channel* ■tod

1 •-

Creen

|»40 j!

Due

I*-!i

ConiURt

FT1 —«-

H Monothrome

H Monothrome

Ansel Adams Effect Step One:

Cot a great shot of a mountainous landscape and want to convert it to grayscale with an Ansel Adams-style conversion (one with intense contrast and depth)? Try Jim DiVitale's great trick for an instant Ansel-like effect, just increase the Red to +160%, the Green to +140% (which adds up to 300,1 know), but then lower the Blue to -200% (bringing you back to 100%).

Channel Mixer

Output Channel Cray -¿H

Source Channel! Red ¡160 *

& Monochrome

[ 140 1

Blue

-200 \

Constant

—Û—

Output Channel Cray -¿H

Source Channel! Red ¡160 *

M Preview

Step Two:

Click OK to apply this "Ansel Adams" Channel Mixer setting, and you'll have a conversion that looks similar to the one shown here.

¡900 uouMvx.trf - u rx lUuwn «.*•• i. um kuu,

¡900 uouMvx.trf - u rx lUuwn «.*•• i. um kuu,

Calculations Method

If there's one dialog box in Photoshop that scares the living daylights out of people, it's the Calculations dialog. It's got an awfully intimidating layout for a dialog that simply lets you combine channels, and that's part of the beauty of it. After you learn this technique, you can "name drop" with it to impress other Photoshop uscjrs. For example, if you're talking color-to-grayscale conventions, just mention in passing, "Oh I don't use Channel Mixer. I do my conversions using Calculations," and they'll act like Puffy just walked in the room. Bling, bling!

Step One:

Open the color photo that you want to convert to grayscale using Calculations.

DCS007Q6JPG $ 100* (RGB)

DCS007Q6JPG $ 100* (RGB)

Step Two:

Co under the Image menu and choose Calculations to bring up the Calculations dialog. This scary-looking dialog lets you choose two channels from your photo that you can blend together to create an entirely new channel. That way, if you have one channel that looks toe dark, and one that looks too light, you can combine the two into one gloriously perfect channel (at least, that's the theory). After you realize that's what you're doing in Calculations, the dialog becomes much less intimidating.

calculation*

Sourc« 1 PSC00TQ6JPG ^

Layer Background i I Channel Red jwj|

Invert f Cancel > Preview

Source 2 DSC00706JPG

layer Channel Red

_ invert

Blending Multiply

Opacttv 100 X

Result New Channel

Sourc« 1 DSC00706 JPCjj: I

Channel Red B|

Sourc» 2 PSC0Q7Q6JPG W

Layer Background

Channel Creen «fj

Blending Multiply : |

Step Three:

So your job is to choose two channels from your color photo and blend them together (using the Blend Modes in Calculations) to create a new grayscale channel that looks better than if you had used Photoshop's default grayscale conversion. It's easier than it sounds. Tirst. start by choosing the Red channel in the Source 1 Channel pop-up menu. Then, choose Green in the Source 2 Channel pop-up menu, as shown here.

Source 1 DSC00706JPG ¡M

Layer Background Channel Cray • \

Source 2 DSC00 706JPG Sj

Layer Background Channel Creen : j

Blending Overlay I '

SouHiJ QSCX)70»JPC W

O-rtty Opacity fO 1»

MKIO"

Step Four:

In this case, with the Blending Mode set to Multiply and the Opacity at 100%, the photo looks too dark. So. to get a better-looking grayscale photo, you can: (a) try different channel combinations (rather than Red and Green, try Red and Blue, or Red and Gray, or Green and Blue, or Blue and Gray, etc.): (b) change the Blend Mode to something other than Multiply and see how it looks; or (c) lower the Opacity setting and see how a more sub-rip blending works

Step Five:

When you've come up with a combination that looks good to you. go to the Result pop-up menu at the bottom of the dialog (by "Result" they mean "what should Photoshop do with this new channel you've created?") and choose New Document. Click OK and a new document will appear with your custom-calculated channel as the Background layer. One last thing: In this new document. go under the Image menu, under Mode, and choose Grayscale.

Creating Duotones

For some reason, creating a duotone in Photoshop (a photo that uses just two colors), is immeasurably more complex than creating one with four colors (as in CMYK). You definitely have to jump through a few hoops to get your duotones to look and separate properly, but the depth added by combining a second, third, or fourth color with a grayscale photo is awfully hard to beat.

Step One:

Open the photo that you want to convert to a duotone. If you're starting with a color photo, you'll have to convert to grayscale first by going under the image menu, under Mode, and choosing Grayscale.

Step Two:

After your photo is converted to grayscale, you can go under the Image menu, under Mode, and choose Duotone.

Indr»e4 Color HCl Color CMYK Color

Cokw MukithtnoH

Auto* Profile Coflvtrt to PrOMt.

Indr»e4 Color HCl Color CMYK Color

Cokw MukithtnoH

Hlisogram

Step Three:

This might seem weird, but the first time you open the Duotone Options dialog, for some reason Adobe set the default Type of Duotone to Monotone (I know, it doesn't make sense). So, to actually get a duotone, you'll first have to select Duotone from the Type pop-up menu at the top left of the dialog.

Auto* Profile Coflvtrt to PrOMt.

O^otort* OpMat

1

1

1

_______

Ink 1

Si Pievtvw

Step Four:

Now that Duotone is your selected Type, you have to choose which two inks you want to use First, we'll look at Ink 1. The first box (the one with the diagonal line through it) is called the "Curve Box," and this is where you determine how the color you choose will be distributed within your photo's highlights, midtones, and shadows. You determine this distribution using a Curve. (Now don't stop reading if you don't know how to use Curves. You don't need to know Curves to create a duotone, as you'll soon see.)

Step Five:

The black box ro the right of the Curve Box is the Color Box (where you choose the color of Ink 1). By default. Ink 1 is set to the color black (that's actually pretty handy, because most duotones are made up of black and one other color). If you decide you don't want black as your Ink 1 color, just click the Color Box and Photoshop's Color Picker will appear so you can choose a different color.

1

J.*

t i.* *

CaMwn Colon

»■» r+Hl&am MM xummc

mgm » f ctmt *

\mmmmmm

;

' Omt

fB—|

■ ,— ■

^HBHHH^H

Trpr < coiai rwnt la km an»« idt* tot.

You'll notice that Ink 2's Color Box is blank. That's because it's waiting for you to choose your second ink color. To do so. click on the box to bring up Photoshop's Custom Color Picker, where you can choose the color you'd like from the list of Pantone^ colors. (Photoshop assumes you're going to print this duotone on a printing press, and that's why it displays the Pantone Coated colors as the default.)

Continued

Step Seven:

When you click OK in the Pantone Custom Colors Picker, the name of your Ink 2 color will appear beside the Color Box. Now that you've selected the two colors that will make up your duotone, it's time to determine the balance between them Do you want more black ia the shadows than your spot color? Should Ink 2 be stronger in the highlights? These decisions are determined in the Duotone Curve dialog for each ink, so click once on (he Curves Box next to Ink 2 to bring up the dialog.

Step Eight:

If you look at the set of fields on the right side of the dialog (as shown in Step Seven's screen capture), the default curve is flat. It mimics your black color in that equal amounts of orange (Ink 2) will appear in the highlight, midtones, and shadows. For example, in the field marked 100%, a value of 100 indicates that 100% shadow areas will get 100% orange ink. Hov/ever. If you wanted less orange in the shadows, type in a lower number in the 100% field (for example, in the capture shown here, I entered 80% for the 100% shadow areas, so now the darkest shadow areas will get 20% less orange, and will appear more black). For 70% ink density areas. I lowered it to 60%. and for the S0% midtone I entered 35%. When you enter these numbers manually like this, you'll see (hat Photoshop builds the Curve for you. Vice versa if you click-and-drag in the Curve—Photoshop fills in the amounts in the corresponding fields.

Duotone Curv*

50 3S X

50 3S X

KM7 M

m

n

.3

Type Duoton« Ij Ink 1 Black

( Owccl

Ink 2

Ink J Ink 4

PAN TONE Orange 021 C

Saw* fij Prrvirw f Overprint Colors— )

Step Nine:

If the idea of creating your own curve freaks you out, all is not lost. Adobe figured that first-time Duotoners might get the "willies," so they included a bunch of presets using popular colors and pre-built duotone curves. All you have to do is try some out to find the one that looks good to you. and use it. These duotone presets were loaded on your computer when you first installed Photoshop. To load them into Photoshop's Duotone dialog, first click the Cancel button in the Duotone Curve dialog we've been working in, and then click on the Load button in the Duotone Options dialog.

Horn k J Duotone

,1 Duotone*

► iß G»»v.'Bmk Ouotonri

,J Qvjdto

iß faxTOnIäj OwMo

iß Trnnn*»

iß frmru Duoionei

( wwd... y

Co to

' Add to favorite* v

( Cancel ^ tn-d

Step Ten:

The Load dialog will appear and by default Photoshop targets the Duotone folder on your drive. If for some reason it doesn't {it's been changed, or you don't see the Duotone folder), then the search is on. In this Load dialog, navigate to your Photoshop application folder. Look inside for a folder called Presets, and inside that look for a folder called Duotones. Inside that folder you'll find another folder named Duotones (you'll also see a folder called Tritones for mixing three colors and Quadtones for mixing four).

Continued

Step Eleven:

In the Load dialog, click on this Duotone folder, and inside that folder is (believe it or not) yet another folder called PAN-TONE Duotones. This is where Adobe carefully buried the individual presets, which you can choose from. Each color listed gives you four choices. The first one includes a duotone curve that gives you the strongest amount of spot color ink, progressing to the least amount with the fourth choice Try a couple out by double-clickmgon the duotone color that you want to load. You'll get an instant onscreen preview, so you can decide if the color and amount of Ink 2 is right. If it isn't, click Load again and pick another from the list to try.

Step Twelve:

When you've got the combination that looks right to you, click OK and the duotone is applied to your photo (as shown).

llOT

J *AVtOMWf> DwDlcmn 0)

J IVo«

J :». »-,,01« t» i

i MMTCmtm CVCWWI

J lMo>M«atf«VM/

I

J *ttcu ftoow

J • « V >

J iiiowtt^W»'

J

J n>»c—*iM i

J »* M I

J lt**«fOT*MJ

J • u 1

Step Thirteen:

Okay, you've got what looks like a perfect duotone (onscreen anyway), but if it's going to press, before you save your file, you have to do a couple of simple but absolutely critical steps to make sure your duotone separates properly. Go under the File menu and choose Print with Preview. When the Print with Preview dialog appears, click on the Show More Options checkbox (as shown). Make sure the pop-up menu just below the checkbox is set to Output.

Halftone Screens

Use Printer's Default Screens

Diamond 1

__ Use Accurate Screens ^ Use Same Shape for All Inks

Auto Screens Printer 2540 dots/inch : j

Screen 150 |' lines/Inch gj ( Cancel > 0 Use Accurate Screen*

Halftone Screens

Use Printer's Default Screens

f OK

Ink Ink 1 (Black)

Cancel

Frequency 1414 lines/Inch [T-j

( Load... )

Angle *S degrees

' Save... )

Shape Diamond

( AutO... }

Q use Accurate Screens

0 Use Same Shape for All Inks

As your duotone sits right now, both colors have the same screen angle. This will likely cause a distracting pattern (called a moire pattern) to appear across your entire photo when printing on a printing press. To avoid this, you have to make Photoshop assign separate screen angles for your duotone. You do this by clicking on the Screen button in the Print Preview dialog. This brings up the Halftone Screens dialog. Click the Auto button to bring up the Auto Screens dialog.

Step Fifteen:

In the Printer field of the Auto Screens dialog, enter the dpi of the device your duotone will be output to. (In this case, I entered 2S40, the resolution of the imagesetter that the prepress depart ment of our print shop uses.) Then call the print shop that's printing your duotone, and ask them at what line screen your job will be printed. Enter that number in the Screen field. Also, turn on Use Accurate Screens (it could help, depending on the imagesetter that is used, otherwise, it will be ignored. Either way, no harm done).

Step Sixteen:

Click OK to close the Auto Screens dialog with your new settings. You'll see in the Halftone Screens dialog that the screen frequencies have now been set for you. Don't change these settings or you'll undo the "Auto Screens" function you just applied (and risk ruining your print job).

Continued

Step Seventeen:

Click OK in the Halftone Screens dialog, and those settings are saved. Now, the trick is how to embed that information into your duotone so it separates and prints properly. Easy—save your duotone as an EPS (choose EPS from the Format pop-up menu in the Save As dialog). This will enable you to embed the screen info into your file to make sure it separates properly on press.

Step Eighteen:

After you choose EPS as your file format, you'll be presented with the EPS Options dialog (shown here). You only have to choose one option: Include Halftone Screen. The screen angles that you set earlier are now included with your file. Click OK to save your file, and now your duotone is ready to be imported into your page-layout application.

NOTE: When creating duotones. we recommend always printing a test to your coloi inkjei to make sure it separates correctly (giving you just two plates: one black and one with your color tint).

ANOTHER NOTE: Again, if you're printing straight from Photoshop to a color inkjer printer or some other desktop printer, you can skip all this "setting screens, halftone dialogs, etc." and just hit print. These extra steps are only necessary if you're going to output your duotone for reproduction on a printing press.

M Int lud» Halflon« kmn _ »«cJuö» Transfer »unoon PD»tScnpt Con:' Mjrugrmrrt

Learn Photoshop Now

Learn Photoshop Now

This first volume will guide you through the basics of Photoshop. Well start at the beginning and slowly be working our way through to the more advanced stuff but dont worry its all aimed at the total newbie.

Get My Free Ebook


Post a comment