Underwater photos enhancement guide
Saturday, August 25th, 2007I was inspired to write this after reading kennysia’s post on underwater photography. I have noticed that the underwater photos look so washed out as they are all very bluish and green.
Water absorbs colors at different depth. When diving deeper, the loss of color will leave you with only blue, black and very little yellow. You will need to get an external flash or attach a colour filter to reduce the bluish cast and maintain the clarity that you expect from your digital camera.
Seems to me many casual divers stop short of getting more accessories after investing in a digital camera with underwater casing. It is understandable because a color filter kit and external flash can be quite costly. So how do you get a more lifelike underwater photographs without spending more money?
Here’s a quick and easy solution…  edit underwater photos using Adobe Photoshop! I will share with you the method that I found from here awhile back. I need to write this down so that I can always refer back to this post the next time I go diving.

This is the sample image that I used.
1. Load the image into Photoshop.
2. Create two extra layers (Layer->Duplicate Layer). You will now have three layers altogether.
3. Select the middle layer and fill it with 50% grey. This is done by going to Edit->Fill and select “50% grey”. Now the middle layer is completely grey.
4. Select top layer and change it’s blending from “Normal” to “Luminosity”. This can be done by going to Layer->Layer Options and select “Luminosity” as the mode.
5. Merge top layer with middle layer (Layer->Merge Down) so that only two layers remain. You will see that your image is now in black and white.
6. Create a new layer on top of your existing layers and fill this layer with red. To do this, select your foreground color and set the color to R: 255 G: 0 B: 0. Then, Edit->Fill and select “Foreground Color”.
7. Change the new all red layer blending mode to “Multiply”. You should now see a top layer completely in red, a middle gray layer and the original layer of your image at the bottom.
8. Merge down the top layer into the middle layer. You will get a very dark red image.
9. Select the merged layer and change the blending mode to “Screen” and merge it to the bottom layer.

Nemo looked more lively now.
10. Run auto levels if you are still not satisfied with the result (Image->Adjust->Auto Levels).

Here’s the final result after adjusted using auto levels.

