If you use a digital SLR, it’s hard to avoid dust spots on the sensor. But if you’re using Capture One, you can fix the dust on one image and then apply the same correction to a whole batch.
You can do this because sensor spots don’t move. Once you’ve got a spot, it’ll be in the same place every time (unless your camera’s dust-removal system dislodges it, or you clean the sensor manually).
Capture One Pro has a spot removal tool that’s pretty effective at removing dust spots from images, and it does this by using pixels from nearby areas of the image. So all you have to do it tell it where the spot is on one image, and then apply the same adjustment to the rest.
Dust patterns do change, so you can’t use the same ‘fix’ indefinitely, but it certainly works well for batches of images from a single shoot. It is wise to glance at the results at the end, though, just to make sure the fix isn’t visible. The spot removal tool works well on areas of plain tone or texture, but it may occasionally mess up an important bit of image detail. If so, try removing the repair from that image – in areas with lots of detail you may find the spot is less obtrusive than the repair.
Anyway, I’ve got the perfect ‘dusty’ camera to use for this example. I took a series of shots on a Fujifilm FinePix S3 Pro, a camera with no dust removal system, and they’ve all got a dark dust spot just above the centre of the frame.
01 What dust spots look like
Actually, dust spots don’t all look exactly like this, but it’s pretty typical. Dust spots are dark and diffuse – the dust is actually on the surface of the low-pass filter in front of the sensor and slightly ahead of the plane of focus, which is why they’re not completely sharp. I’ve zoomed in to 100% so that the dust spot – and the repair – is easier to see.
Capture One’s Spot Removal panel is in the Details tooltab. There are two options: Dust and Spot. You might think the Dust option would be the obvious one, but having tried both out I’ve found the Spot tool is better – for this job, at least.
02 Click to remove
Here’s the Spot Removal tool in action. The mouse cursor becomes a circle with a set of crosshairs in the centre. The idea is that you place the crosshairs over the centre of the spot, adjust the size of the tool so that it’s just larger than the spot (you can use the square bracket keys as a shortcut), then click to remove it.
03 Fixing more spots
That first spot is gone in an instant, and you can use the same technique on any others – you can make other repairs different sizes, too. You can modify or remove them, but you don’t select them directly; instead, you need to use the pop-up menu in the Spot Removal panel (shown here on the left).