This is the second blog in the series to explain how I edit my underwater photos in Adobe Lightroom. In this section I will explain how I change the exposure and contrast.
Please Click here to read the first blog post.
Exposure is the measurement of lightness and darkness within an image. A correctly exposed image has a good balance between the two. There will also be no area which is too bright or too dark.
A good way to measure the exposure is to use a histogram.
If the image is overexposed or too bright the graph will lean to the right.
If the image is underexposed or too dark the graph will lean to the left.
These three histograms are screenshots from lightroom. I used the same image and adjusted the exposure to create my example histograms. Notice the arrows in the top corners of the histogram. On the overexposed histogram it is highlighted blue and on the underexposed, green. You will also notice that the graph itself has different colours in different areas. This is to show you the exposure of each colour and not just the general exposure. This can help to give an idea of which parts of the image are over or under exposed.
With underwater photography you will often find that the blues are towards the right side of the histogram. This is generally because the top section of the image will be blue water. As we get deeper under the water we loose light and therefore the top section of our image is often brighter than the bottom. Meaning that the blues are often the brightest part of the image.
Water is denser than air and therefore light travels a shorter distance through it. This affects the colour, contrast and sharpness of the images you will produce. We have already discussed the colours in the previous blog post. Now lets talk about the contrast.
A contrast is a striking difference between two things. In the case of photography it is referring to the differences in tone. Usually light or dark tones but it can also be between different colour tones.
This is the before and after shots of a silhouette taken on the U.S.A.T Liberty Wreck.
The only thing I changed on this image was the contrast. I used the contrast slider under the basics tab and moved it to the right.
For this image I used two Inon Z240 strobes to light up the anemone and clownfish. The left strobe was closer to the anemone and left some unpleasant highlights on that side of the image.
I started the editing on this image by moving the highlights slider all the way to the left to completely remove the bright spot.
Next I added a tiny bit of contrast by moving the contrast slider slightly to the right. This made the anemone stand out from the background a bit more.
Finally I reduced the overall exposure a little more. This made the anemone stand out even more.
This image was taken at about 20 meters on a cloudy day, using a single Z240 strobe which I positioned above the subject.
I started by increasing the exposure of the image using the exposure slider and moving it to the right.
I then increased the contrast a tiny amount.
The image was finished with some white balance changes.
This is an image taken in bad visibility of the U.S.A.T Liberty Wreck. The bad visibility reduced the contrast of the image even more.
The first thing I did was increase the contrast by moving the slider to the right.
The next thing was to increase the overall exposure.
I then increased the contrast again
Then I focused on changing the colours and removing some spots, before reducing the blacks to make them darker.
As you may have worked out I was having trouble getting the image to stand out.
My final option was to increase the clarity. This makes the details of the image stand out more.
This did the trick. However it did make a lot of particle in the water also stand out. I finished the image by removing these particles.
In my next blog I will explain how I remove spots and marks from my images.
If you would like to learn more about Adobe Lightroom please download my PDF Lightroom course.