“Blend If” sounds just like you stop talking suddenly half way through.
True story 🙂
All joking aside, Blend If is actually an underrated tool in Photoshop. It’s hidden in Layers Style and it’s rarely used or not normally mentioned by photographers.
This is because most of them don’t know it exists or even how to use it.
It’s the EASIEST way of blending in Photoshop.
I highly recommend try this out because you can add this to your arsenal in the art of blending!
The Seldom Seen “Blend If”
So, where do you find it?
You can access the menu for Blend If by double-clicking a layer in the Layers Panel to bring out the Layer Style panel. If your layer is locked as background, double click to convert it to a layer first before double-clicking it again to bring out the layer style.
Once the Layer Style panel is opened, by default, this is what you see (picture above). On the left, you will see a list of things and on top is the Blending Options.
There are lots of other things in the middle but all you need to pay attention to is at the bottom – the Blend If slider adjustments.
There are 3 parts ofBlend If you should know about:
- The drop down menu is set to gray by default. Click to change to any of the red, green or the blue channel.
- This layer: changes you make here will only apply to the layer you are working on.
- Underlying layer: change you make here will apply to the layer underneath.
How Blend If Works
Blend If Gray
I usually keep it to gray. Essentially this tells Photoshop to blend the image based on the luminosity value of the pixels, a bit like luminosity masks.
Blend If works well if there is a good contrast in your image because Photoshop can separate different parts of the image more easily.
If your image has a low contrast, then you can go to the channels panel and inspect the red, green and blue channel to see if any of the channels can separate what you want to blend better. You can then click on the drop down menu to select that channel to blend.
Changes on the slider bar will only affect the layer you are working on.
Note there is an arrow (circled in red) on each end. The left arrow is for the blacks and the right arrow is for whites (you can see the value from 0-255).
Why is it not shadows and highlights instead?
Because it’s “Blend If Gray” and it works on the luminosity value of the pixels.
Feel free to download the PSD file in this tutorial and work together to help you understand better.
(1) If you move the arrow for blacks to the right (towards whites), the blackest blacks will start to disappear on the layer you’re working on. In other words, pixels to the LEFT of the black arrow will be transparent and pixels to the RIGHT of the black arrow will be visible. (picture below)
(2) If you move the arrow for whites to the left (towards blacks), the whitest white will start to disappear on the layer you’re working on. In other words, pixels to the RIGHT of the white arrow will be transparent and pixels to the LEFT of the white arrow will be visible. (picture below)
Changes on this slider bar will affect the layer underneath and NOT the layer you’re on.
(1) If you move the black arrow to the right (towards whites), the blacks that are underneath the current layer will be revealed.
(2) If you move the white arrow to the left (towards blacks), the whites that are underneath the current layer will be revealed.
Splitting The Arrows
You may have already noticed that there is a vertical line in the middle of each arrow. If you hold down opt (Mac) or alt (Win) + click to move half of the arrow, it will split.
Moving half of the arrow makes the changes smoother on the image, similar to the feathering effect.
You can first move the arrow (in full) to a point and then split it to fine tune your adjustment.
Example 1: Blending 2 Images
What does all this mean in practical terms? How is this going to help in your workflow?
Let’s look at some examples.
I took this in Northumberland Nationa Park in England. I was unlucky because the weather was foggy all day long. I walked to this famous Sycamore Tree and this is what I got.
Now we are going to add some beautiful sky (picture below) to make the image more cheerful! You can download the images I use for demonstration.
Follow these steps:
- Open up both files as layers in Photoshop with the blue sky image on top of the tree image. The sky image is smaller so go ahead and resize and make it larger to fit the frame.
- Select the blue sky image and double click to bring out the Layer Style panel.
- Because we want the foreground of the underlying layer to be revealed, we will use the arrows in the Underlying Layer.
- Move the black arrow in the Underlying Layer to the right to about 140, split the arrow and move the right half of the arrow further to the right to about 190.
That’s it! It is THAT SIMPLE! The result is a clean and perfectly blended image.
The foreground is too bright considering the light source is coming from below the hill. You can use the Overlay Gradient in the Layer Style panel to add some shadows to make it more natural.
Example 2: Protecting Shadows Or Highlights
The use ofBlend If is not only restricted to blending images. You can use it with curves tool, levels tool, hue/saturation, photo filter, literally anything you can think of.
Image how powerful Blend If can be if you master it and apply it to your workflow.
The possibilities are endless!
We are going to use the image of Castle Sant’Angelo that I took in Rome, Italy.
It was taken at sunrise. You can see the beautiful golden light coming from the right.
I quite like the cobblestones in the foreground but the sky is a bit too bright for me. If I apply a curves adjustment to darken the sky, the foreground will become even darker.
To protect the shadows in the foreground, all you need to do is:
- Double click the curves adjustment layer to bring out the Layer Style panel.
- We want the blacks on this layer (the curves adjustment layer) to disappear, so we will make adjustments on the slider bar on This Layer.
- Drag and move the black arrow to the right to about 30, split it and move it further right to about 140.
This is what you should see after.
As you can see, the highlights have been toned down and the beautiful details in the shadows are still visible. The result is a more balanced, beautiful image.
Blend If is an easy-to-use tool in Adobe Photoshop to help you blend your images or adjustments rapidly without any complicated steps.
It’s an underrated, powerful tool that you should consider trying.