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Using the Photoshop Curves Tool

Using the Photoshop Curves Tool
The Photoshop curves tool is perhaps the most powerful and flexible image transformation, yet it may also be one of the most intimidating. Since photographers effectively paint with light, curves is central to their practice because it affects light's two primary influences: tones and contrast. Tonal curves are also what give different film types their unique character, so understanding how they work allows one to mimic any film — without ever having to retake the photograph. Similar to Photoshop levels, the curves tool can take input tones and selectively stretch or compress them. If you follow two spaced input tones, note that their separation becomes stretched as the slope of the curve increases, whereas tones get compressed when the slope decreases (compared to the original diagonal line). Note: curves and histograms shown above are applied to and shown for luminosity (not RGB) The curves shown above are two of the most common: the "S-curve" and "inverted S-curve." Inverted S-Curve Related:  Courbe de tonalité / Tone curVe

courbe des tonalités LR 4 sur Tuto.com Ce tuto vidéo "Courbe des tonalités avec Lightroom 4" fait partie d'une formation complète qui vous permettra de découvrir plus en profondeur Lightroom. Découvrez sans plus attendre la formation "Lightroom 4 : Les fondamentaux" dans laquelle vous retrouverez cette vidéo et tous les fichiers source utilisés par le formateur.Les fichiers source ne sont pas fournis dans les vidéos vendues à l'unité. La courbe des tonalités sert à corriger plus finement le contraste dans des zones précises de l'image. Jetez un oeil à ces autres tuto Lightroom 4 Pour vous faire un avis, voici un extrait de quelques secondes. La version complète et téléchargeable de ce tuto Lightroom 4 de 5 minutes est proposée dans une résolution plus grande que l’extrait suivant : video2brain , Editeur pro Toutes les formations de Video2brain Gilles Théophile, auteur dans cette formation Toutes les formations de Gilles Théophile Témoignage des clients de video2brain Lire les autres témoignages D'autres tuto de video2brain

Image Posterization Posterization occurs when an image's apparent bit depth has been decreased so much that it has a visual impact. The term posterization is used because it can influence your photo similar to how the colors may look in a mass-produced poster, where the print process uses a limited number of color inks. This effect ranges from subtle to quite pronounced, although one's tolerance for posterization may vary. Any process which "stretches" the histogram has the potential to cause posterization. Stretching can be caused by techniques such as levels and curves in Photoshop, or by converting an image from one color space into another as part of color management. Visually inspecting an image is a good way to detect posterization, however the best objective tool is the histogram. Note the tell-tale sign of posterization on the right: vertical spikes which look similar to the teeth of a comb. Posterization occurs more easily in regions of gradual color transitions, such as smooth skies.

Photography, Cameras and Taking Better Pictures Tone Curve Lightroom Tutorial This extract is from chapter 4 of the Wiley title 'Lightroom 4: Streamlining Your Digital Photography Process' by Nat Coalson. After adjusting the settings on the Basic panel, you can further refine the photo's contrast by manipulating specific tone ranges with the Tone Curve panel (see Figure 4–26). If you’ve used curves in Photoshop or other software, the Tone Curve panel may seem familiar to you. Most photos probably won’t need the Tone Curve You should usually focus the majority of your tone adjustment work on the Basic panel instead of the Tone Curve, which is becoming outdated in the era of parametric processing. Parametric Curve Lightroom’s default Tone Curve is parametric: it adjusts sections of the tone scale, rather than from individual points. Adjust the curve to increase or decrease contrast in specifi c areas of the tonal range. Figure 4-27 You can adjust the Tone Curve in the following ways: Figure 4-28 Region Sliders Figure 4-29 Point Curve Point Curve Presets Inverted curves

Using the Photoshop Levels Tool Levels is a tool in Photoshop and other image editing programs which can move and stretch the brightness levels of an image histogram. It has the power to adjust brightness, contrast, and tonal range by specifying the location of complete black, complete white, and midtones in a histogram. Since every photo's histogram is unique, there is no single way to adjust the levels for all your photos. The levels tool can move and stretch brightness levels in a histogram using three main components: a black point, white point and midtone slider. All examples below will use the levels tool on an RGB histogram, although levels can also be performed on other types of histograms. When considering adjusting the black and white point levels of your histogram, ask yourself: is there any region in the image which should be completely black or white, and does the image histogram show this? If the image is fully black while dragging a black or white point slider, then no clipping has occurred.

UK Commercial photography - Northlight Images Réglages et Courbe [2/2] Si vous avez bien suivi l’article de la semaine dernière, vous avez du voir qu’il reste quelques réglages de bases que nous n’avons pas encore abordés. Aujourd’hui, on va donc s’intéresser à la clarté, la saturation et la vibrance. On va aussi aborder la courbe des tonalités histoire de démystifier cet outil bien pratique. N’hésitez pas à participer au sondage : “Quel logiciel de développement utilisez vous?” à la fin de l’article. Voici les derniers points de la partie réglages de base : la section Présence. Son effet? Son effet? Son effet? On a vu la semaine dernière comment lire l’histogramme et comment ajuster les réglages pour avoir une photo bien exposée : l’exposition, la lumière d’appoint, les noirs, la récupération, la luminosité et le contraste. L’outil courbe se décompose en 5 parties: 1. On est content maintenant qu’on sait ça mais, comment on utilise la courbe ? La courbe se lit “de bas en haut et de droite à gauche”. Sélectionnez l’outil.

Understanding Digital Camera Histograms: Tones and Contrast Understanding image histograms is probably the single most important concept to become familiar with when working with pictures from a digital camera. A histogram can tell you whether or not your image has been properly exposed, whether the lighting is harsh or flat, and what adjustments will work best. It will not only improve your skills on the computer, but as a photographer as well. Each pixel in an image has a color which has been produced by some combination of the primary colors red, green, and blue (RGB). Each of these colors can have a brightness value ranging from 0 to 255 for a digital image with a bit depth of 8-bits. A RGB histogram results when the computer scans through each of these RGB brightness values and counts how many are at each level from 0 through 255. The region where most of the brightness values are present is called the "tonal range." Lighting is often not as extreme as the last example. A histogram can also describe the amount of contrast.

Making prints match your screen The other day Keith was asked if calibrating and profiling a monitor would make someone's screen match their prints? Some thoughts and potential solutions for this common problem. This article was written several years ago and has (Sept 2010) been updated with some newer links and information. Can my prints ever match my screen? The short answer is no, ...but the reasons may be much more varied than you first thought, and with care you can get the two very close. Hopefully this short guide (and the links to other more detailed information) will be of help? After profiling and calibrating your monitor... Let's assume that you have read all the articles about how important it is to have your monitor calibrated. You are not quite happy with the quality of prints you are getting and decide to buy a screen calibrator like the Spyder4express or even the basic Pantone Huey. Does this now mean that your prints will look better? Well maybe, but it really is only part of what you need to know... Remember:

Mastering Lightroom: How To Use the Tone Curve Panel In this short tutorial I will show you how to use one of the easiest and most powerful tools found in Lightroom – the Tone Curve. In my previous tutorial about black & white conversions , I briefly showed you how to use the HSL Panel’s Luminance section to control the lightness of separate colors of the image. Using the Tone Curve Panel is very similar as it also allows you to control the lightness and darkness of various parts of a given photograph, however, rather than altering separate colors, the Tone Curve tool controls certain ranges of actual tones in the image. What Is It? The Tone Curve represents all the tones of your image. While all of this may sound very technical, it is in fact quite simple to adjust. Region Curve and Point Curve Lightroom has two different Curves you can work with. But then there is another Curve you can use if you do need to make adjustments not possible with the Region Curve, and it is called Point Curve. The Easy Part 1) How To Make Your Image Pop

Tutorials – Sharpness Sharpness describes the clarity of detail in a photo, and can be a valuable creative tool for emphasizing texture. Proper photographic and post-processing technique can go a long way towards improving sharpness, although sharpness is ultimately limited by your camera equipment, image magnification and viewing distance. Two fundamental factors contribute to the perceived sharpness of an image: resolution and acutance. Acutance High Low Resolution For digital cameras, resolution is limited by your digital sensor, whereas acutance depends on both the quality of your lens and the type of post-processing. Photos require both high acutance and resolution to be perceived as critically sharp. Acutance: High, Resolution: Low Acutance: Low, Resolution: High Acutance: High, Resolution: High Sharpness also depends on other factors which influence our perception of resolution and acutance. Low Noise, Soft High Noise, Sharp Sharpness also depends on viewing distance.

Camera metering modes matrix pattern evaluative center spot partial Digital SLR camera metering modes Understanding metering modes is important for every photographer if they are to take correct exposures. To improve your photography you need to know when to set your digital camera on matrix, pattern, evaluative, center weighted metering, spot and partial metering. Metering modes can be one of the most frustrating settings for beginners to SLR photography. If you have ever taken an under or over exposed photograph using program mode (P), aperture priority (A Nikon, AV Canon) or shutter priority (S NIkon, TV Canon), chances are you've set the metering mode incorrectly. Metering systems work by measuring the amount of brightness within a scenery or object, then sets the exposure accordingly. What metering modes are you likely to find on your digital camera The majority of digital SLR cameras will give you a choice of at least three different metering systems. Matrix metering on Nikon cameras is called either Pattern or Evaluative on other models.

Tonal Adjustments in the Age of Lightroom 4 The Power of Curves In Photoshop, my primary tonal adjustment tool has been the Curves Adjustment layer. I would wildly guess that 85% of the adjustment layers in my Photoshop files are curves. Working with Shadows This was a snapshot made by my friend Karl Kroeber (see his real work at www.karlkroeber.com), and is a jpeg file. Some very dark shadows The dark trees above are almost completely black. Now Photoshop does offer what could be called a predecessor to the new Lightroom Shadows and Highlights sliders, but it works in a very different way, and not quite as well. Shadows Lightened using Photoshop's Shadows/Highlights Adjustment But, importing this jpeg into Lightroom 4 (or opening it into Adobe Camera Raw 7), provides a great result using the Shadows slider, with minimal halo problems (below). Shadows Lightened Using Lightroom 4's Shadows slider This tonal legerdemain must be very hard, because it took Adobe many years to get it working this well. Working with Highlights May, 2012

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