Match Color
The homogeneity of all the images in a series of photographs is essential. Density, contrast, hue, and saturation are key elements. Source files often contain disparities, which Photoshop can resolve with its Color Match adjustment.
Series of images are designed through associations of similar themes or subjects. But they still need to be tuned. Most often, like a tuning fork in music, a reference photo serves as a model for the other images in terms of hue, saturation, brightness and contrast. In general, adjustments to brightness and contrast, with a view to overall consistency, pose no great difficulties. Hue and saturation adjustments, on the other hand, are trickier to master.
Workspace Organisation
Photoshop offers a quick and efficient way to match colors between two images. It can be found in the Image > Adjustments > Match Color menu. But before using it, a few preparations are necessary to make the job easier. Open your reference image in Photoshop, then the one you’ll adjust to balance its appearance. We recommend working on 16-bit rather than 8-bit images (switch to Image > Mode > 16 Bits/Channel if you’re working on a Jpeg).
As the color match setting is not an adjustment layer or a Smart Filter, we will work on a copy of the image background (Layer > Duplicate Layer…). Background copying is only necessary on the image to be modified, not on the reference image.
Adding the reference image next to the target image makes observing the adjustment’s effects easier. To do so, select Window > Arrange > 2-up Vertical.
Photoshop Color Match
The Color Match setting can consider the entire source image or a selection. The latter is used to match a specific color. Use the Selection Rectangle tool to locate the dominant color zone. In our example, we’ve done this in the middle of the image, on the blue in the reflections of the building’s glass cladding. Once these preparations have been made, select the target image, then Image > Adjustments > Match Color…
Source And Destination Images
The Match Color window has two frames. Above is the Destination Image (the image being modified), and below that of the reference image. The latter is curiously named Image Statistics. In this lower frame, the Source field indicates the reference file. The Layer field is actually the Background. In our example, we match two different images which are two different files. We could also use the color match setting to homogenise not two different files, but two different layers in the same file.
Adjustment Sliders
As we’ve selected the blue in the building reflections in the source image, we can check or uncheck this selection to calculate the colors that will be applied to the target image. The preview shows the difference with and without the selection. The Luminance slider increases or decreases the brightness of the target image, with a default value of 100. The Color Intensity slider adjusts the saturation of colors in the target image with a default value of 100. The Fade slider has the same effect as the opacity of a layer. As we have applied the color match on a separate layer, we prefer to play with the layer’s opacity by leaving this slider at 0. The Neutralize option automatically removes any dominant color in the target image. As we’re looking for the dominant color here, we uncheck the option.
Discover the photography courses at Spéos
Spéos offers various training courses ranging from simple one-week photography workshops (initiation and advanced level) to 3-year courses. The long courses to become professional photographers allow you not only to master all the photographic techniques and its vocabulary (blurs, hyperfocus, sharpness zone, depth of field, backlighting, focal length, shutter release, autofocus, wide-angle, rule of thirds, etc.), but also all the stages of shooting and image processing.
Visiting the school allows you to discover the premises, the studios and the equipment, and is undoubtedly the best way to familiarize yourself with your future way of working. This is why, in addition to the open days, Spéos offers throughout the year personalized visits by appointment to come and discover the school with a member of the team.
Text and photos: Philippe Bachelier, teacher of Printing techniques at Spéos
