Post-Processing for Beginners: Intermediate Photoshop

This image was shot on the same dive as the tutorials below. The final result was accomplished using only the techniques in this tutorial

By Andrew Marriott

Photoshop is a monster—there’s no way around it. What makes it great is that there are so many ways to accomplish similar effects, and this means that there are nearly endless ways to begin to master it. In these tutorial videos, we show you just one way to go about things. It is highly recommended that you jump in and play with things on your own. Many of the techniques we share are things that were discovered via trial and error. There is no single formula for success.

In this series of tutorials, we focus on steps that go beyond the basic adjustment buttons. Those buttons are critical, but it is important to move beyond them and onto some of the icons on the left side of the screen. If you were asked what the most annoying thing in your underwater pictures is, backscatter would surely be among your top three. To help with this, we’re focusing on removing backscatter and noise from your photos. To go along with this, we also introduce some more advanced masking techniques, and finally we use color filters to replicate the effect of using colored filters on your housing.

The images chosen for this tutorial were from a very green and murky dive on the wreck of the Olympia Maru in Coron, Philippines. These shots were chosen as they were the worst that were shot during this entire trip! You always want your post-processing to be subtle, but for the sake of this tutorial, we are going throw a box of hammers at you. None of this was rehearsed: These videos were recorded in a single take so there was no practice. You get to see the process in all its trial-and-error glory!
 

Another shot from this same dive using only these basic techniques

Backscatter Removal and Noise Reduction

Backscatter is the bane of underwater photography. Nothing ruins a great shot quite like seeing a giant blizzard appear after you’ve hit the trigger. You can eliminate most of this problem while you are shooting. It’s all about strobe positioning and having the cones of light from your strobe intersect right at your subject. Taking an additional moment to properly set your strobes will save you an hour in post. This tutorial is for those of us who forget to set our strobes, were too lazy, or we just plain forgot.

The key to getting rid of those pesky snowflakes is the Spot Removal tool. This is probably the single most powerful tool for underwater photographers in Photoshop. In just a few clicks of the band-aid button, we can get rid of those annoying spots that appear in almost every image. Ever wondered how professional photographers have no backscatter in their images? Well, now you know the dark secret!
 

Here is our starting point: too dark, a lot of backscatter, composition is off, and colors are wrong
 

Our first image is of a juvenile lionfish and some black coral, which is orange, of course. The RAW file was very underexposed. In Lightroom, we increased the exposure, decreased the highlights and deepened the shadows. The goal was to make the subject visible, which we failed to do in camera. There was a second shot taken right after this that was correctly exposed, but for the sake of practicing our post skills, let’s tackle the harder one.
 

In Photoshop, our first task is to get rid of the most egregious backscatter. If we had spent an hour clicking madly away, we could have eliminated most of it, but you probably wouldn’t want to watch that video. After erasing the backscatter, we move into some mild noise reduction. This is a subtle step, and you can probably do it just as well in Lightroom using the slider there.

Our last task is to add some color filters. You can do this on the camera, but then you will be stuck with that color in your RAW file. It’s usually better to shoot auto white balance and then use these software filters to accomplish the same effect—but in this case it is “non-destructive.” Finally, we discover that you often don’t want to apply an effect to the entire image. To selectively apply effects, we use masking, but as you see in the videos it’s not always just black and white.
 

The result after a few minutes in post. We could really clean this up if we spent the time

Intermediate Masking

Aside from layers, masks are the most powerful aspect to Photoshop. They let us selectively hide or expose portions of layers. What many users don’t realize is that a mask does not just have to be black or white. By applying different shades of gray on our mask we can alter the opacity of the mask. A 50% gray color on a mask will reduce the opacity of the mask 50%. This may seem somewhat arcane at first, but if you know Photoshop and masks, you will realize the power of using the gray scale.
 

Our second prize-winning image! Once again too dark, too much backscatter, and too much green
 

The use of grays in our masks allows us to create subtle edges. There is nothing more distracting than a hard edge in a Photoshop effect; it is a dead giveaway to what you did, and it just looks sloppy. The first way to combat hard edges is to adjust the hardness of your brush. Big, soft-edged spray patterns make excellent subtle edges. You can take it to the next level by adding shades of gray to the mix. Make your masks black in areas you want to completely cover, and then work gradually towards white the further you get from these points. It takes more time, but the results are incredible!
 

In this second image, we use masks to cover up our noise reduction. We need to do this, as when we reduce the noise, we lose detail. In this case, we masked the fish to preserve the detail in them. When creating masks, make sure to use the backslash ( ) key, as it will add a red color to your workspace showing where the mask is covering.

The image was badly underexposed, but we fixed this in Lightroom beforehand. There is substantial backscatter that is removed using the spot removal tool, and finally we use color filters to correct the color balance. Keep in mind that you can mask color filters. This is useful if you need to color-correct a background but want to preserve the color revealed by a strobe in the foreground. Apply a filter and then mask off the foreground—problem solved!
 

Our final result. Not perfect, but at least it is viewable. Remember, we picked the worst images for these examples!

Color Filters

The color filter tool is a fast and easy way to color-correct. It works very well for underwater photos, as we are usually in need of red or magenta. Instead of doing this on your camera, let Photoshop do it for you. In post, you can selectively mask, change density, tweak exact color and apply different blending methods. No physical filter will give you this level of control. So, unless you are shooting video, color filters are best left to Photoshop. The more time you spend in Photoshop, the more you get a sense for what you need to do to get the correct coloration.
 

This one is brutal—more backscatter than water!
 

In these photos from Coron, I knew that a violet filter at about 20% density would be perfect. The final image of the three was also the first time we stacked filters. In this case we used the violet filter for an image wide correction, and then we went back in and added a warm filter to only the mast using a mask. This image was also the worst in terms of backscatter; in fact, there was more backscatter than water visible!

It would have been impossible to click on all the backscatter in this shot using the spot removal tool. Luckily there is a solution to this, and that is to apply a type of noise reduction filter. If you choose Filters > Noise > Dust & Scratches, you can blur out backscatter. Originally created for the restoration of old, scanned photos, this filter is an animal when it comes to killing backscatter. Set it to a radius of six pixels and it will blur out most particles.
 

There is a cost to using this filter, of course, and that is the loss of detail. For this reason, this filter works best when your background is out of focus. A sharp background will be lost, so make sure you are okay with this. In this example, we apply the filter and then use a mask to cover up the mast. This preserves detail only in the mast and allows us to blur out much of the remaining backscatter. You will need to play with this tool to get to the point where you can create natural-looking images, but remember that in Photoshop if you can imagine it, then you can do it.
 

It may not win any competitions, but at least you can tell what you are looking at

Final Thoughts

The best way to learn Photoshop is to pick a couple of tools and play with them on a variety of pictures. Only when you have a good handle on these tools should you move on to something new. Photoshop is often viewed as having a steep learning curve. This is true, but it is better to think of it as a thousand smaller learning curves associated with each tool. Viewed as a whole, it looks incredibly complex, but when you break it down into smaller pieces, it becomes much more manageable. Trial and error is the best way to learn, so don’t be shy—jump in and give it a go!