Photographic compositing has been with us since the dawn of photography. The merging of two or more separate images into one is seen as a way of extending our creativity. In the digital age, of course, this has become a whole lot easier with the use of Photoshop’s layers and blend modes. As well as compositing different images, layers and blend modes can be a great way to improve the look of your images. Today we are going to look at five of the best blend modes for a photographer, but before we start we should briefly look at what a blend mode is.
What is a Blend Mode?
In layman’s terms, a blend mode works out specific differences between two layers, the upper layer and the lower layer. Depending on the blend mode, these differences can be in exposure, contrast, color or other factors. The blend mode then uses this information to merge the two layers together.
The blend modes can be found on the top left of layer palette once there are two or more layers available. To use a blend mode, select the upper of the two layers that you wish to blend. Another useful tool to be aware of when using blend modes is the Opacity slider, this is found to the top right of the layers palette.
This is an excellent mode for outdoor photography such a landscapes particularly if they look light and washed out. A useful technique is to create a curves adjustment layer to reduce the highlights a touch, then apply the multiply blend mode. This has the effect of darkening the image by the equivalent of one stop. If your image is now too dark, you can back the blend mode off a little using the Opacity slider.
This is useful mode for boosting contrast within an image. If you have a flat, low contrast image you can get an instant contrast boost by duplicating the original layer and applying the Soft Light blend mode. Again, the effect can be backed off using the opacity filter but if you need a further contrast boost, duplicate the upper layer again, the Soft Light mode will also automatically copied to the new layer.
Overlay is in many ways similar to Soft Light in that it is a contrast based mode. One of its most powerful uses is in adding graduated filters to flat skies. To do this, create a blank layer above your original. Using the graduated fill tool with a neutral graduation selected, drag the fill tool down from the top to about two thirds of the way down the image. Apply the Overlay blend mode to this graduated layer and you will see the graduated filter effect darkening your sky. Again, you can back this effect off using Opacity slider. You can also apply the Soft Light mode to this for a more subtle effect.
Lighten is an excellent mode for merging identical shots with different exposures. For example, if you took a series of identical shots of a cityscape through sunset and wanted to merge a night image with an earlier, lighter image that had more detail, Lighten would be the mode to use. It works by removing all the dark areas from the upper image and bending purely the lighter areas into the layer below.
This mode is extremely useful for boosting contrast without affecting saturation. Normally, when you boost the contrast of an image using either levels or curves, the color is also boosted, often leading to an over saturated feel. To avoid this, create a duplicate adjustment layer, either curves or levels, carry out your contrast adjustment, then switch the blend mode to luminosity.
The combination of layers, adjustment layers, blend modes and opacity combine to make the layers palette in Photoshop one of its most powerful functions. They give us the ability to work on specific elements of an image such as contrast or luminance without affecting other elements. Although they might seem a little daunting at first, blend modes, and in particular the five listed above, are a powerful tool in the photographer’s post production workflow.