Dave Stevenson
All of which I’ve covered here before, but there’s one thing that routinely makes me wish I’d stuck with 35mm. Not for long, obviously, but the presence of dust in my images is a stark reminder of digital’s Achilles’ heel. With film, dust problems were generally limited to a single frame. Then, the frame would be wound into the canister, and the next frame would be dust-free.
Not so with digital. If dust gets into your camera and glues itself to the sensor, you’re stuck with it, either until the dust falls off the sensor, or until you employ a blower to get it off yourself. I’ve got a reasonable amount of faith in the anti-dust mechanisms employed by the likes of Nikon, Canon and Sony, but, particularly with fast cameras, a speck of dust only needs to adhere itself to your sensor for a few minutes to prove a recurrent irritation once your images are on your Mac. On a camera that shoots upwards of 8fps, for instance, you’ll be looking at perhaps dozens of shots requiring post-production attention.
The best cure is prevention, as the saying goes, but while I’d like to tell you I take scrupulous care when changing lenses in the field, time – and nature in particular – doesn’t wait, and I’d rather deal with dust spots and cleaning than miss the moment. The drawback, apart from raising the odds of expensive internal damage, is that dealing with dust is an everyday reality. Luckily, spot-healing is something that’s been part of Photoshop since I can remember, and Lightroom offers similarly powerful tools. Indeed, considering the sheer mathematical complexity of healing spots in your images, it’s amazing that Lightroom works as well as it does in a single click.
A more recent discovery, however, was spurred by the unwelcome appearance of a few dozen images, each sporting identical dust spots. The shots were taken over the course of a few days, and the pace was frenetic enough that it prevented careful checking. The result? Hundreds of dust spots that needed sorting out before more general retouching could start. Luckily, Lightroom came to the rescue.
Lightroom doesn’t make a huge deal of it, but it’s possible to apply the same processing to a series of images with the Sync button. The name doesn’t help: ‘Sync’ suggests duplicating files across several devices, but in this case it means synchronising edits across a range of images.
The first step is to fix one image. If your shots are from the same few days, dust spots should be roughly the same size and in the same place – the only thing that will make them change at all will be a change in your camera’s aperture. Using Lightroom’s dust controller is simple enough: Q selects it and the square bracket keys ([ and ]) make it smaller and larger.
Removing dust could barely be simpler, particularly on uncomplicated areas such as continuous blue sky. Areas of intense detail, such as foliage, require a bit more thought. With your mouse pointer sized to obscure the dust spot, click and drag to determine where Lightroom will sample. Drag the cursor around until the dust is seamlessly removed. Repeat until dead, or until all the dust spots in your image are obscured.
The result is one totally dust-free image. However, you’ve also inadvertently made a map of where the dust spots will be on the next few images and one of Lightroom’s hidden tricks is the ability to use that map on other images. Tap G to take you back to an overview of your library and select all the images that suffer from identically placed dust spots. Shift-click to select them one by one – or, as in cases where you’ve made a quick collection, Cmd-A will grab the whole group. Hit Sync Settings at the bottom of the right-hand column.
This opens the fantastically-powerful Synchronize Settings window, from which you can duplicate edits and effects across as many images as you want. In this case, we’ve done nothing to the first image except remove dust, so check the Spot Removal box and hit Synchronize. Simple – an entire range of images fixed for dust. Lightroom even distinguishes between landscape and portrait photos and applies your changes intelligently.
Almost, anyway. Every image is different, and dust spots will be more or less noticeable on different images depending on your camera’s settings and the scene you’re shooting. In this image, the main area of dust has been cleaned, but the clear blue sky on the left of the frame was obscured in our reference image. In this case, it’s simple enough to just add another healing spot. In the future, however, if you suspect dust could be a problem in your shoot, it pays to take a picture of something plain – a wall, or continuously coloured sky – at the smallest aperture available before you begin. That way, when you get back to your Mac, you’ll have a ready-made, worst-case scenario image to create a dust map that you can use for syncing to your other images.
