Adjusting individual parts of an HDR image in Photoshop can be a complex task. Your goal should be to do this in a way such that each change can be switched on and off and be undone individually. This is usually called non-destructive editing. In Photoshop, the most important image adjustments can be applied as adjustment layers. An adjustment layer is a separate layer that contains the information of the adjustment. For example, a Levels layer can be used to increase the contrast of an image. You can easily switch on and off this increased contrast effect by switching on and off this layer. You can also make several different Levels layers and apply different contrast settings to compare them. This is one of the major advantages of Photoshop over most other image editing tools.
Assume that you are working on a photos with some white buildings, a few blue windows and the sky. Most probably, you want to adjust each one of these elements separately. This means that you may have 2, 3 or more adjustment layers for each of the elements. Very quickly, this can get too complex to manage.
The best way of dealing with this complexity is to make use of groups. A group can be added to a Photoshop project via the “Create new group” button at the bottom of the Layers palette. The idea is to structure a photoshop project into the different regions which require different treatment (e.g. the sky, the building, the lawn, etc.) and to create a group for each of these regions. The adjustment layers necessary for a specific region will be added to this region’s group.
For example, when you start working on the sky,
- Add a group and give it the name “sky”. Giving expressive names to groups helps you maintain an overview over your project.You can do this by double-clicking on the group. This will open the following dialog.
- Create a selection that only reveals the sky.
- Select the “sky” group by clicking on it.
- Turn the selection into a mask (using the Create layer mask button in the Layers palette). Your “sky” group now has a mask such that anything you place in this group only applies to the sky. None of the adjustment layer placed in the group requires a mask of its own.
- While the group is highlighted, add a Levels adjustment layer using the Adjustments palette. The new Levels layer will be automatically placed inside the group. Adjust the contrast of the sky by changing the setting of the Levels layer. This will not affect any other part of the photo.
- Highlight the “sky” group (or any other layer already in this group) and add a Saturation adjustment layer. Again, the new layer will be placed in the “sky” group, affecting only the sky.
To try something different, you can also create a duplicate of an existing group with all contained layers and masks. Simply drag the group onto the “Create new layer” button at the bottom of the Layers palette. You can switch on and off an entire group (by clicking of the eye icon left of the group) or change its opacity in the same way it is done for an individual layer. This is a very convenient way of grouping related adjustments and treating them as a unit.
In order to be able to quickly identify your groups, you can also change their color. This has nothing to do with the colors in your image. It only changes the color of the group (and all layers in it) in the Layers palette. Simply double-click on the group in the Layers palette to bring up a small dialog that lets you assign a name and a color to the group.
Groups may also be nested. So you can create a group inside a group. This can be very handy if you want to work on a part of the image that is contained within a part that you have already created a mask for. For example, if you want to work on the clouds in your image, place a new group called “clouds” inside the “sky” group. Select the clouds and create a mask for the new “clouds” group without bothering about the other parts of the image.
I create a new group for any complex adjustment, leading to projects that may have up to ten groups.