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Tutorial - Sky Swapping and reflection

I've had a few people hit me up after recently posing an image recently asking for tips on sky swapping and reflections, so I thought i'd go all out and post a step by step tutorial on exactly how to do it.

If you're anything like me you've watched plenty of youtube vids on how to do the above but find most of them to either be so effn complicated they can't be followed, or too simplified that what you end up creating looks nothing like what you expected. So here we go:

Sky Swapping

Okay so firstly,  to do this, you're going to need an image with a good sky. There's plenty online you can grab, but to be honest i've never found anything too amazing outside of those paid stock image websites. Pro tip: When you're out shooting and your lucky enough to score a colorful sunrise/sunset, take a few shots of just the sky to keep for these sort of occasions.

Also,  keep in mind when you're shooting that this process is much, much easier when you have a well defined horizon. Even if you have trees ect along the horizon, a good amount of contrast between the ground and the sky is what you need. I'll explain this in more detail in a minute.

Before you upload the main image and the sky into Photoshop, it's a good idea to make sure you've applied the same settings or preset to both images (including white balance, this is important). This will help make sure the colors are similar between the two. I should also mention at this point, you've gotta have an image with the correct lighting to match the sky as well. A high contrast, daylight image with shadows is going to look ridiculous when matched up with a dark red sky.

So, load the base image as your background layer into photoshop, then your sky as the next layer.  The sky I used was from an image snapped in landscape format, where as the the base image is in a 4x5 portrait format. From here you should drop the opacity of the sky layer down to about 50-60%, this is just so that you can move and resize the sky layer into the position you want, while you can still see the base layer. You can see in my image I moved the light source of the red sky inline with the train tracks in the main image.


Once you've done this, push the opacity of the sky layer back up to 100%, select your main image layer, and make the sky layer invisible. From here go about selecting the sky in the base image using the quick selection tool. This shouldn't take too long if you have a high-contrast horizon, but it's not going to be exact. Once you've got the sky selected, hit "select and mask" and then go for the "refine edge" tool. Hit the plus icon, and run the brush over all the surfaces that the quick selection tool didn't get. This can actually be the most time consuming process, and won't always work too well if you dealing with low-ish contrast between the ground and sky. Take your time with getting the edge right, as it'll make the final image look that much better.

Quick Select.jpg
I've got the "minus brush selected in this image, but make sure you hit the "positive" brush to refine the edge

I've got the "minus brush selected in this image, but make sure you hit the "positive" brush to refine the edge

Once you've got the selection down pat, hit OK and then click on the sky layer to make it active. Make it visible again, and hit the "add layer mask" button. Voila, you should have your new sky.

Layer Mask done.jpg

Just so you know: I used to hate Photoshop. I tried to watch tutorials, but every time "layer mask" came up I would get the shits and just turn the computer off, until I came across someone who made the explanation simple... The best way to describe a layer mask is as a window between two layers. If the layer mask (window) is black, you can't see anything through it, if it is white, you can see everything through it. What we've done above, is select all the ground detail and create a layer mask, blocking it all out of the sky layer in this area. Hopefully this makes sense. It confused the shit out of me for so long!

The image isn't going to look perfect at this point, but that's probably because the exposure balance is off between the two. In my image the foreground is too bright. To fix this, you want to create a curves adjustment layer and position it between the two layers. This way it will only affect the foreground. If you haven't played with curves adjustment it basically lets you adjust exposure and contrast in your image. If you want to adjust the exposure, click in the very middle of the line running between the bottom left and top right, and drag down toward the bottom right a fraction, this will darken the foreground a bit.


Once you've got the balance right, save it, and go back into Lightroom and make any finishing touches you want to.


I did this after going back into lightroom and making a few minor adjustments (radial filter around light source, and darken/brighten a few other areas) so I'll assume we're working with a new image here.

First up, select what you want to reflect using the rectangular marquee tool, and copy it to a new layer. Select that new layer, then go to the transform menu and select flip vertically. Use the "move" tool to drag it down, it should snap into position at the bottom of your original selection. You might be happy with the image at this point, but an absolute mirror image reflection usually doesn't look all that realistic as it can look too perfect.

Reflection 1.jpg

There are two things you can do next. I didn't do this on the above image, but you can select the reflection layer, and add in a motion blur from the filter menu. Play around with the amount of blur you like but you're best to use an angle of zero degrees.

Next is the trick part. If you want to add realistic looking ripples you need to create or download a displacement map. When I was working out how to do this i managed to find a few useful tutorials online that will explain to you how to do it.

It's late, i'm tired, i'm just going to give you the displacement maps i've created.

Copy this link into your browser to download them.

All you need to do now, is select the reflection layer, then go to the filter menu. Select, distort then displace. 

The tutorials I've watched suggest using totally different settings, and i haven't been able to really work out what they mean, but the horizontal and vertical scale settings i used are below, and seemed to work okay. Once this part is done you should have the ripples in the reflection but you might find the reflection layer pushes up a bit into the original layer. You can fix this up by adding a layer mask to the reflection layer, and then using a black brush over the areas that have pushed over. See shot below.

Reflection 2.jpg

Hopefully you're now good to go!

This might all seem confusing as hell, and like i said, i've seen and read so many tutorials and half of them are just absolute shit. Leave a comment or question below and I'll see if i can help you out!

Simon ClaytonComment