Dust spots are an unfortunate fact of life when shooting with a DSLR. Thankfully, Lightroom has tools that help to remove ‘dust bunnies’ from your images. However, dust is not the only enemy, especially for underwater photographers. We also have to contend with backscatter.
In the (rather ordinary) image of a nudibranch above, we can clearly see lots of spots and speckles. These spots are not dust spots, they are backscatter – the light from my strobes hitting some of the tiny particles suspended in the water, reflecting the light back into the camera
Hopefully, if you use Lightroom (and you really should be as it is a great all-in-one image editing and management package) then you already know about the spot healing brush (Shortcut Q)? As the name suggests, this is the tool to use if you are trying to clone out or heal parts of an image, maybe due to dust spots, backscatter, or even a piece of rubbish spoiling a pristine beach (although it would be better to actually remove the offending item before taking the photo)
Whilst working on this spotty image I remembered an additional option that is often overlooked when using the healing brush. Visualise spots (Shortcut A, when the clone brush is activated – or use the tickbox that is highlighted in red in the above image) presents a very basic black and white image, where dust spots show up as white specks on a black background, making them glaringly obvious.
As can be seen in the image above, finding the blemishes is much easier when the image is in such a contrasty black and white format.
The strength of this negative style image can be adjusted simply by moving the slider, highlighted in red in the above image. This helps to find the smaller specks that were not so obvious with a lower setting. It is down to you as to how far you go with spot removal.
I hope this post helps you with the thankless task that is dust removal.
You can buy (for instant download) Lightroom 6 from Amazon here.