Silver Fa st Ai
Figure 4.61 Selecting one of the HDR modes left not only cancels any existing adjustments, it grays out their menus to ensure that no additional processing is performed on the scan. Here are the image adjustment tools in normal mode top right and again in HDR mode bottom . location on every scan. Since different brightness settings were used for each scan, SilverFast can blend composite pixel data to form a wider dynamic range. It is much like merging two exposures, one light, one dark, and...
Cumulative Curves
The effects of the Point Curve and Parametric Curve are cumulative. If contrast adjustments are applied to both windows , each setting will be applied to the image when it is rendered as a gamma-corrected TIFF or JPEG file. Figure 4.39 I've added colored overlays here to differentiate the four slider regions you define in the Parametric Curve. Yellow indicates the Shadows, green shows the Darks, cyan identifies the Lights, and magenta defines the Highlights. At right, you can see I have...
Apple and the Gamma 18 Mystery
Why did Apple choose a gamma of 1.8 for its graphics rendering Common wisdom has it that this gamma was a closer match to the output of its LaserWriter printers. Remember those This fudge was an early attempt to match the monitor to the print, without benefit of soft proofing and other color management tools. Photoshop also includes dot gain settings of 10, 20, 25, 30, and 35 percent as working space options. Once again, this was an attempt to simulate the behavior of an output device in this...
A Raw Conundrum
For all of the benefits of raw files mentioned earlier, I am compelled to note one potentially significant limitation. Every camera manufacturer understandably wants to apply proprietary enhancements to their raw captures so that their images outperform the competition. Unfortunately, this has led to a proliferation of undocumented raw file formats. If you own digital cameras from more than one company, you've got multiple file formats that can only be fully decoded via raw converter software...
Linear Capture
Regardless of the color filter array technology, all sensors capture data in a linear fashion. That is, a sensor will always record a 2x increase in luminance as twice as bright. What's the big deal, you say Well, human vision perceives light in a subjective and decidedly nonlinear manner, as Figures 4.20 and 4.21 demonstrate. We never register a doubling of luminance as being twice as bright. We will not even perceive identical luminance increases in the same way if one occurs to pixels in...
Demosaicing Algorithms
Back in Collecting Photons, I discussed the fact that most digital cameras only capture one-third of a scene's actual color information. To produce a full color image, the missing pixel data must be interpolated from existing color values. This process is referred to as demosaicing. All software vendors have their proprietary algorithms for computing missing color data, and there is no shortage of debate among photographers as to the best raw conversion engine. But, in general, the math...
Reading the Negative
Obviously, you cannot capture detail or sharpness that does not exist on the negative, so it is important to examine the film on a light box with a loupe during the image selection process. You need to identify areas of subtle highlight and shadow detail, as well as determine whether there is sufficient sharpness in areas of primary focus. Not every image has to be tack sharp to be effective, of course. Abstract expressions of form and shape can produce a compelling narrative. But it's...
Resampling Pixels
After an image is digitally captured, there is no shortage of options for changing the number of pixels contained within the file. Downsampling refers to the act of throwing out pixels in order to reach a smaller print size or resolution, as seen in Figure 4.8. This is a relatively harmless procedure. The only drawback is that drastic reductions produce a less sharp result. Selecting Photoshop's Bicubic Sharper algorithm when downsampling is an effective way to compensate for this loss....
Tools Palette
The Marquee tool M is most often used for selecting broad swaths of an image when hard edges and abrupt tonal transitions are not a concern. You simply click and drag until the area you want to select is within the marquee's boundaries. You have the option to choose a rectangular or elliptical shape. You can also select a single row or column of pixels. See Figure 5-6 for Marquee tool options. Figure 5.6 In addition to Normal, the Marquee tool can be set to a Fixed Ratio or Fixed Size. Setting...
ColorControlled Black and White
PrintFIX PRO 2.0, the hardware software profiling bundle from ColorVision, has added some features that bring monochrome output squarely into a color-managed workflow. As in its previous version, PrintFIX PRO 2.0 can be used to generate color profiles by measuring patches from a supplied color target. What sets this package apart, however, is the ability to print an Extended Grays target, like the one shown in Figure 3.45. Measuring this target with the bundled spectrophotometer characterizes...
QuadTone RIP Big Control Small Price
Like many great ideas, the genesis of QuadTone RIP QTR grew out of frustration. Its creator, Roy Harrington, had a printer and ink combination that was no longer supported with a printer driver on his operating system of choice. This motivated him to write a shareware program, based on open source code, which could serve as a printer driver for his large format Epson. Roy's background as a black-and-white photographer led him to add support for a number of third-party monochrome ink sets, as...
ICC Profiles and Negative Film
ICC scanner profiles do not apply to negative film, whether color or black and white. Remember that the goal of using a profile is to render the original as faithfully as possible. This is very useful for slides and prints, but not for negatives. It's rare that you'll want to reproduce an orange film mask or an inverted-color image To address this situation, most scanning software offers a range of settings tailored for specific film emulsions that automatically neutralizes the mask and...
Mastering Digital Black and White
A Photographer's Guide to High Quality Black-and-White Imaging and Printing Professional Technical Reference 2007 Thomson Course Technology, a division of Thomson Learning Inc. All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system without written permission from Thomson Course Technology PTR, except for the inclusion of brief quotations...
Color to Monochrome Conversion
At first glance, having to convert every raw file to monochrome can seem like an unfair burden placed on black-and-white photographers. Wouldn't it be great to just have a grayscale digital camera instead Until that camera becomes commercially available, we can take solace in the fact that powerful conversion tools exist that allow for a level of control over hues and saturation that were simply not possible with panchromatic film even with a bag full of filters. The fact that ACR is bundled...
Highlight Recovery
I mentioned in the sidebar Blown Highlights Lost in Space that in-camera histograms are less than reliable indicators of highlight clipping when you're shooting raw. But what happens when you really have clipped the highlights ACR includes a Recovery slider that can reclaim some clipped highlight data, as shown in Figures 4.36 and 4.37. I'll emphasize the word some because impressive though it is, the Recovery feature is not magic. In highlights where only one channel is clipped, Figure 4.33 If...
Grayscale ICC
QTR attracts much attention as an inexpensive alternative for generating high quality black-and-white output. Its most significant contribution from a color-management perspective, however, is the bundled QTR-Create-ICC tool. This single piece of software allows anyone with a spectrophotometer to create an ICC-compatible grayscale profile, regardless of the monochrome ink set they have installed. You simply print a provided grayscale target and measure the density of its patches. The result is...
Piezography and the Quad Black Revolution
Jon Cone's Piezography system was the first commercially available method of producing fine art black-and-white prints in the digital darkroom. A large part of its appeal lay in the fact that it was developed for use on desktop Epson printers, providing a low-cost entry to fine art printing. Until the debut of Piezography in 2000, getting even a satisfactory monochrome print from an inkjet was an exercise in frustration. The Epson printer drivers provided a limited tonal range. Shadows blocked...
Wet Mounting
Unless you own a drum scanner, you may not be familiar with the technique of wet mounting film. One of the great benefits of a drum scan is that the film is mounted directly to an acrylic drum and wrapped tightly, ensuring a consistent plane of focus over the entire area of the film, as shown in Figures 2.24 and 2.25- But in high-resolution scans, placing film in direct contact with an acrylic Figure 2.24 Wet mounting on a drum requires a specialized mounting station on which to lay out and...
Test Charts and Images
The stated goal of a color-managed workflow is predictable, consistent results. An important element in maintaining such a system is determining not only when there is a problem, but also identifying the culprit. When a print no longer matches what you see on the monitor, is the problem with the on-screen display or the print output An easy way to visually track the behavior of a device is with a test image. It does not have to be as precise or elaborate as the test files shown in Figures 2.47...
Building the Digital Darkroom
One of the more daunting tasks confronting any digital photographer is choosing among the large number of hardware and software options. In this chapter, I'll take an in-depth look at the tools you need to outfit your digital darkroom. A credit card and a quick trip to any big box retailer will allow you to generate a print from a digital file. But producing the highest caliber of digital output requires identifying tools that will complement, if not enhance, your creative vision. The digital...