Chris Gatcum shows you how to add focus to your wildlife photographs
WHETHER it be feather or fur, the textures in a wildlife image can really bring your subject to life. However, these details can also be difficult to reveal. Without a degree of sharpening, details can blend into a single homogenous tone, especially if you need to crop your shot to make your subject more prominent in the frame. All digital images benefit from a certain degree of sharpening, no matter how expensive (or otherwise) your camera and lenses are, simply because of the way in which digital images are formed. There are two options when it comes to choosing where you sharpen your images: in-camera or in your image editing software. If you record raw files, software- based sharpening is the only option, and even if you shoot JPEGs, sharpening your images in your editing program is the better option.
In the example here, extreme levels of sharpening
SOFTWARE USED Adobe Photoshop Cs5 SKILL LEVEL ■■■■■ TIME TAKEN 10-15mins KEY TOOLS Layers, Unsharp Mask, Masks are required, but this can have an adverse effect on surrounding areas that do not require sharpening quite so much. This usually results in obvious halos and increased noise, but there are ways to avoid these unwelcome artefacts while still optimising the sharpness of the subject. Here’s how it’s done.
Software tips and techniques Retoucher’s guide
1. Open your image and select the Crop tool. In this shot the squirrel is too small in the frame, so I’ve created a tighter, slightly less conventional, square crop. Unfortunately, zooming in on the subject in this way exaggerates the slight softness in the fur, which is what we will be resolving.
2. It’s a good idea to perform any editing on a duplicate layer so you can revert to the original picture if you need to, or blend and fade your edits for greater control over the end result. To do this, select Layer>Duplicate Layer from the main menu to create your working layer. I’ve named my duplicate layer ‘Sharpening layer’.
3. There are numerous ways that you can sharpen an image, but I employ a fairly traditional technique based around Photoshop’s Unsharp Mask (USM) filter. Start by converting the image from RGB to Lab mode using the lmage>Mode>lab Color menu option. When asked if you want to flatten your layers, choose Don’t Flatten.
4. Open the Channels palette and select the Lightness channel. This will allow you to sharpen the detail in the image without affecting the colour channels, which reduces the chance of introducing coarse sharpening artefacts.
5. Open the Unsharp Mask filter (Filter>Sharpen>Unsharp Mask] and set the Amount, Radius and Threshold. For this image, settings of 250,1.5 and 25 were set respectively. Don’t be afraid to oversharpen the image at this stage, as you can fine-tune it later.
6. Now that the entire photograph is sharpened, switch back to RGB mode (lmage>Mode>RGB Color). Again, when asked, select Don’t Flatten.
7. The next step is to apply the sharpening selectively, so that it affects only the main subject. Again, this is to prevent unwanted artefacts from creeping in. With your sharpening layer selected, choose Layer>Layer Mask>Hide All. A black rectangle will appear next to the layer thumbnail, indicating a layer mask that is concealing the sharpening.
8. To reveal the sharpening, select the black mask icon and then choose the Brush tool. With white set as the foreground colour, ‘paint’ the image where you want to apply the sharpening. This will remove the mask in that area, revealing the sharpened image behind it. Switch the foreground colour to black to paint areas back in.
9. When you are happy with the mask, adjust the opacity of the sharpened layer to refine its intensity and blend it with the raw’ background image. The end result increases the apparent sharpness of the subject, without introducing unwanted artefacts into the surrounding areas or affecting them in any other way.
