Adobe 13101332 User Guide - Page 126

Compensating for dot gain in film using transfer functions

Page 126 highlights

Adobe Photoshop Help Using Help | Contents | Index Producing Consistent Color (Photoshop) Back 126 To create a grayscale or spot-color profile based on a custom dot gain: 1 Print a hard proof with calibration bars included. (See "Setting output options" on page 473.) 2 Using a reflective densitometer, take a reading at one or more marks of the printed calibration bar. 3 Do one of the following: • In Windows and Mac OS 9.x, choose Edit > Color Settings, and select Advanced Mode. • In Mac OS X, choose Photoshop > Color Settings, and select Advanced Mode. 4 Under Working Spaces, for Gray or Spot, choose Custom Dot Gain. 5 For Name, enter the name for the custom profile. 6 Do one of the following: • Using your densitometer readings, calculate the required adjustments, and enter the percentage values in the text boxes. For example, if you have specified a 30% dot, and the densitometer reading is 36%, you have a 6% dot gain in your midtones. To compensate for this gain, enter 36% in the 30% text box. • Click to add an adjustment point in the dot gain curve, and drag the point to change its value. The value then appears in the appropriate text box. • Click OK. 7 Save the custom profile. (See "Saving and loading working space profiles" on page 119.) To create a grayscale profile based on a custom gamma: 1 Do one of the following: • In Windows and Mac OS 9.x, choose Edit > Color Settings, and select Advanced Mode. • In Mac OS X, choose Photoshop > Color Settings, and select Advanced Mode. 2 Select Advanced. 3 Under Working Spaces, for Gray, choose Custom Gamma. 4 For Name, enter the name for the custom profile. 5 Specify the desired gamma value, and click OK. 6 Save the custom profile. (See "Saving and loading working space profiles" on page 119.) Compensating for dot gain in film using transfer functions When using CMYK color profiles, you cannot customize dot gain settings. However, you may be able to compensate for dot gain from a miscalibrated imagesetter by using transfer functions. Transfer functions enable you to compensate for dot gain between the image and film. For example, the Transfer function makes 50% dots in the image print as 50% dots on film. Similar to dot gain curves, the transfer functions let you specify up to 13 values along the grayscale to create a customized transfer function. Unlike dot gain curves, transfer functions apply only to printing-they don't affect the image color data. Using Help | Contents | Index Back 126

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
  • 164
  • 165
  • 166
  • 167
  • 168
  • 169
  • 170
  • 171
  • 172
  • 173
  • 174
  • 175
  • 176
  • 177
  • 178
  • 179
  • 180
  • 181
  • 182
  • 183
  • 184
  • 185
  • 186
  • 187
  • 188
  • 189
  • 190
  • 191
  • 192
  • 193
  • 194
  • 195
  • 196
  • 197
  • 198
  • 199
  • 200
  • 201
  • 202
  • 203
  • 204
  • 205
  • 206
  • 207
  • 208
  • 209
  • 210
  • 211
  • 212
  • 213
  • 214
  • 215
  • 216
  • 217
  • 218
  • 219
  • 220
  • 221
  • 222
  • 223
  • 224
  • 225
  • 226
  • 227
  • 228
  • 229
  • 230
  • 231
  • 232
  • 233
  • 234
  • 235
  • 236
  • 237
  • 238
  • 239
  • 240
  • 241
  • 242
  • 243
  • 244
  • 245
  • 246
  • 247
  • 248
  • 249
  • 250
  • 251
  • 252
  • 253
  • 254
  • 255
  • 256
  • 257
  • 258
  • 259
  • 260
  • 261
  • 262
  • 263
  • 264
  • 265
  • 266
  • 267
  • 268
  • 269
  • 270
  • 271
  • 272
  • 273
  • 274
  • 275
  • 276
  • 277
  • 278
  • 279
  • 280
  • 281
  • 282
  • 283
  • 284
  • 285
  • 286
  • 287
  • 288
  • 289
  • 290
  • 291
  • 292
  • 293
  • 294
  • 295
  • 296
  • 297
  • 298
  • 299
  • 300
  • 301
  • 302
  • 303
  • 304
  • 305
  • 306
  • 307
  • 308
  • 309
  • 310
  • 311
  • 312
  • 313
  • 314
  • 315
  • 316
  • 317
  • 318
  • 319
  • 320
  • 321
  • 322
  • 323
  • 324
  • 325
  • 326
  • 327
  • 328
  • 329
  • 330
  • 331
  • 332
  • 333
  • 334
  • 335
  • 336
  • 337
  • 338
  • 339
  • 340
  • 341
  • 342
  • 343
  • 344
  • 345
  • 346
  • 347
  • 348
  • 349
  • 350
  • 351
  • 352
  • 353
  • 354
  • 355
  • 356
  • 357
  • 358
  • 359
  • 360
  • 361
  • 362
  • 363
  • 364
  • 365
  • 366
  • 367
  • 368
  • 369
  • 370
  • 371
  • 372
  • 373
  • 374
  • 375
  • 376
  • 377
  • 378
  • 379
  • 380
  • 381
  • 382
  • 383
  • 384
  • 385
  • 386
  • 387
  • 388
  • 389
  • 390
  • 391
  • 392
  • 393
  • 394
  • 395
  • 396
  • 397
  • 398
  • 399
  • 400
  • 401
  • 402
  • 403
  • 404
  • 405
  • 406
  • 407
  • 408
  • 409
  • 410
  • 411
  • 412
  • 413
  • 414
  • 415
  • 416
  • 417
  • 418
  • 419
  • 420
  • 421
  • 422
  • 423
  • 424
  • 425
  • 426
  • 427
  • 428
  • 429
  • 430
  • 431
  • 432
  • 433
  • 434
  • 435
  • 436
  • 437
  • 438
  • 439
  • 440
  • 441
  • 442
  • 443
  • 444
  • 445
  • 446
  • 447
  • 448
  • 449
  • 450
  • 451
  • 452
  • 453
  • 454
  • 455
  • 456
  • 457
  • 458
  • 459
  • 460
  • 461
  • 462
  • 463
  • 464
  • 465
  • 466
  • 467
  • 468
  • 469
  • 470
  • 471
  • 472
  • 473
  • 474
  • 475
  • 476
  • 477
  • 478
  • 479
  • 480
  • 481
  • 482
  • 483
  • 484
  • 485
  • 486
  • 487
  • 488
  • 489
  • 490
  • 491
  • 492
  • 493
  • 494
  • 495
  • 496
  • 497
  • 498
  • 499
  • 500
  • 501
  • 502
  • 503
  • 504
  • 505
  • 506
  • 507
  • 508
  • 509
  • 510
  • 511
  • 512
  • 513
  • 514
  • 515
  • 516
  • 517
  • 518
  • 519
  • 520
  • 521
  • 522
  • 523
  • 524
  • 525
  • 526
  • 527
  • 528
  • 529
  • 530
  • 531
  • 532
  • 533
  • 534
  • 535
  • 536
  • 537
  • 538
  • 539
  • 540
  • 541
  • 542
  • 543
  • 544
  • 545
  • 546
  • 547
  • 548
  • 549

U
sing H
elp
|
C
on
t
en
ts
|
Inde
x
B
ack
126
Adobe Photoshop Help
Producing Consistent Color (Photoshop)
U
sing H
elp
|
C
on
t
en
ts
|
Inde
x
B
ack
126
To create a grayscale or spot-color profile based on a custom dot gain:
1
Print a hard proof with calibration bars included. (See
S
etting output options
on
page
473
.)
2
Using a reflective densitometer, take a reading at one or more marks of the printed
calibration bar.
3
Do one of the following:
In Windows and Mac OS 9.x, choose Edit > Color Settings, and select Advanced Mode.
In Mac OS X, choose Photoshop > Color Settings, and select Advanced Mode.
4
Under Working Spaces, for Gray or Spot, choose Custom Dot Gain.
5
For Name, enter the name for the custom profile.
6
Do one of the following:
Using your densitometer readings, calculate the required adjustments, and enter the
percentage values in the text boxes.
For example, if you have specified a 30% dot, and the densitometer reading is 36%, you
have a 6% dot gain in your midtones. To compensate for this gain, enter 36% in the 30%
text box.
Click to add an adjustment point in the dot gain curve, and drag the point to change its
value. The value then appears in the appropriate text box.
Click OK.
7
Save the custom profile. (See
S
a
ving and loading w
or
k
ing spac
e pr
ofi
les
on page
119
.)
To create a grayscale profile based on a custom gamma:
1
Do one of the following:
In Windows and Mac OS 9.x, choose Edit > Color Settings, and select Advanced Mode.
In Mac OS X, choose Photoshop > Color Settings, and select Advanced Mode.
2
Select Advanced.
3
Under Working Spaces, for Gray, choose Custom Gamma.
4
For Name, enter the name for the custom profile.
5
Specify the desired gamma value, and click OK.
6
Save the custom profile. (See
S
a
ving and loading w
or
k
ing spac
e pr
ofi
les
on page
119
.)
Compensating for dot gain in film using transfer functions
When using CMYK color profiles, you cannot customize dot gain settings. However, you
may be able to compensate for dot gain from a miscalibrated imagesetter by using
transfer functions.
Transfer functions enable you to compensate for dot gain between the image and film. For
example, the Transfer function makes 50% dots in the image print as 50% dots on film.
Similar to dot gain curves, the transfer functions let you specify up to 13 values along the
grayscale to create a customized transfer function. Unlike dot gain curves, transfer
functions apply only to printing—they don’t affect the image color data.