A long exposure photo of the London Tower Bridge just around sunset.

Don’t worry, River Thames was just as muddy as ever. One of the reasons I love post-processing so much is because I can do whatever I like. I am not married to reality, like a documentarist. I am an artist. I process my photos until I get something I like. I don’t particularly like a muddy river, and the blue one looks much better.

But how did I make the water blue?

I made a virtual copy of the image in Lightroom. I now had two identical photos. On one, I started to play with the HSL panel to make the water blue. This made the rest of the image look terrible, but that’s OK, that is why I made a virtual copy.

When I was happy with the water, I selected both images, and exported them to Photoshop as Layers, and then I blended the water into the normal photo, and the result is this image.