Lightroom’s Adjustment Brush

Adobe Lightroom has two effective tools to adjust specific areas of a photo: the adjustment brush tool (ABT) and the graduated filter tool (GFT). There are actually three tools including the Radial Filter but it is effectively an adjustment brush with a radial effect, something I don’t use. Rather than applying image adjustments to the entire image these tools affect only certain zones. Because the Graduated Filter has its own features and controls, it is covered in a separate post.

All the adjustments that can be applied globally are available for the ABT. These include: color temperature, tint, exposure, contrast, whites, blacks, highlights, shadows, clarity, dehaze, saturation, sharpness, noise, moiré, defringe and color.

There are more precise ways to target specific areas but they are only available with Photoshop and a PS plug in from Tony Kuyper, the TK 7 Panel. These programs allow for masking based on highly specific brightness values plus color, saturation and hue. This is pixel based masking which selects only pixels in a particular range and is more precise than the ABT and the GFT.  However, this is a relative comparison; Lightroom tools do a very satisfactory job in lots of situations. Plus there are luminosity and color masking functions with the ABT and the GFT but again masking via PS and the TK 7 software is far more precise and comprehensive.

I start photo processing by adjusting the overall global values such as exposure, contrast and placement of lights and darks. I often have to favor a particular zone such as foreground or sky, get this one zone right and subsequently adjust the remaining zones with the graduated filter tool that can be applied across the photo horizontally. Once the photo’s overall adjustments are set, I use the ABT and GFT to target specific areas such as lightening dark shadows or emphasizing highlight areas.

Adjustment Brush Use

Activate tool – click control panel icon or hit K key.

ABT effects are painted over the image with a round tip whose diameter, edge feathering, flow and hardness can be set to different values. The brush is used like a paint brush and dragged over image areas to be affected. Drag the brush with the left side of the mouse held down to apply the effects.

Brush characteristics are selected from the options at the bottom of the tool panel.

Size – The diameter of the brush inner circle controlled by the slider or keyboard keys: right bracket key to enlarge and left bracket key to reduce.

Cross Hairs in the Brush Center – this is the spot where pixels to be modified are sampled. Therefore, the larger the brush diameter the greater the chance that you will have gaps in coverage. So, double check the coverage by using the “show/hide visibility” option which colors the painted areas with light magenta, or display the actual black & white mask by tapping the O key. You will see any gaps and uneven coverage. I usually paint with this option checked so I can see my work as I go along.

Feather Size – this is the width of the band around the center circle that gradually blends the hard center effect into surrounding areas. The wider the feather, the softer and less obvious the transition. Control via slider or Shift key and the  +/- keys.

Flow– modify flow values to allow the use of multiple paint strokes over an area to build an effect. With the flow at low settings you go repeatedly over an area to build the effect but it in a controlled manner. Flow does not affect the degree of adjustment set. If you have +1.0 stop of exposure set, no matter how many strokes you make the adjustment will not exceed this exposure value.

Density – Sets the amount or strength for the adjustment effect selected.

ABT “pins” – where you start an adjustment is marked by a round pin. If you have made multiple ABT edits, their pins will be visible on the image.

Edit– click an existing ABT pin to go back and modify the effects. A round pin shows where you started a new ABT effect and if you left click on it, the pin becomes editable.

Auto Mask – check box to activate this option which applies a mask to the areas outside the areas you paint.  The areas you paint are colored magenta and these are the areas for adjustment. Masking prevents bleed over into adjacent areas as long as they are sufficiently different in color and tone. To give the program good input information on what you want adjusted, start painting well within the adjustment areas and not near or on a transition zone. ABT auto masking is not be as precise or refined as Photoshop techniques.

View the actual mask – it may help to look at the actual mask that has been created by taping the O key. A black and white, full screen size mask appears showing the selected areas white and the mask protection areas black. White reveals pixels and black protects them. This view will certainly show gaps caused by the cross hair not passing over important pixels. Tap the O key again to close this view.

Magnify the Image – It often helps to work on the image in magnified view such as 100 %. Work will be slower but a lot easier and far more precise.

Erase – clicking “Erase” switches the tool into an eraser to subtract from existing adjustment areas. Very helpful for cleaning up adjustments that have spilled over into adjacent areas.

Apply Multiple Adjustments Within a Single ABT Application – Usually only one or two adjustments are dialled in but there is no limit.

Proportional changes to multiple ABT areas – if you want to modify multiple areas and have the changes applied equally to all of them at once, put your cursor over a pin, click it and drag on the pin with the left mouse held down. A left drag decreases the effects and right drag increases effects.

Assign a group of setting to a single brush application – the letters A and B at the top of the options box allow assignment of two different brush type settings. You might want one to be a soft, large feather, moderate density brush. The other could be a narrow feather, hard edge brush. Just establish your adjustment parameters and click A or B and they will be assigned for further use with this brush. The forward slash key toggles between A & B brushes.

Have fun and enjoy the tool; it does a good job in a skilled hand and you don’t have to use Photoshop unless you want high precision and more control options.