Photoshop Tutorial : Cross Processing In LAB Mode
Another one of those effects that has been around for donkeys years, but still worth while seeing how it will turn out on one of your images. You will find loads of different ways of doing this, this is the way I choose to do it. So lets get started, you can borrow my image below to practise on if you like ….. copyright is mine etc.,
Because you can use this effect on a colour and a B&W image, we may as well set this up right from the start. Firstly, you need to make a new file from the one you have open – so go to Image>Duplicate in the top tool bar and when the dialogue appears, either name the new file or leave the default name. Click Ok to accept and then click back on the original file and duplicate the background layer. Open a B&W adjustment layer and click OK to the default.
Click back on the copy file … the one without the B&W adjustment layer, and go to Image>Mode and choose LAB and then the Don’t Flatten option. Click on the top layer and then click on the Channels Palette. Click on the A channel and then go to Image>Adjustments>Equalize, then click on the layer that says LAB (you might have to put a pair of sunglasses on LOL) and then click on the Layers tab at the top of the layers palette.
You are now going to drag this layer over to the other image. Make sure you have the move tool selected, press V on the keyboard. Hold down the Shift key on the keyboard (this will centre the image) and then drag the other to the other image. Your layer stack should look like the image below. I have the B&W adjustment layer turned off for now.
Change the blend mode of the layer to Colour and drop the opacity of the layer to around 30%. The percentage will vary depending on what size image you are working on. You will also need to add a blur to this, because as you can see, it is a bit bitty. Go to Filter>Blur>Gaussian Blur and I used a Radius of 5 pixels.
You could also add a mask at this stage if you wanted to hide some of the effect. So, on to the next part. Go back to the copy layer where you did the edit on the A channel and step back so that you just have the 2 layers ago. Click on the Channel tab at the top of the layers palette and then click on the B channel. Go to Image>Adjustments>Equalize click on the LAB layer and then click on the Layers tab at the top of the layers palette. Take the layer over to the other image in the same way as you did before and do the same adjustments, you should now a layer stack that looks like the image below.
This is where the fun begins for you. Try different blend modes on the 2 layers, add the B&W layer into the mix ……. play and have fun 🙂
I have merged the 2 layers together and changed the blend mode to Overlay. Added a mask to the layer and used a 50% gray over the grass area. Added a selective colour layer set to Absolute and Whites – added 10% Yellow. And that’s it. You could have used the B&W adjustment layer if you wanted, I chose not to. Remember that you don’t have to use both the A and B channels you can just use one of them. Below is a comparison image and then the single image.