How to Use the Object Selection Tool in Photoshop 2020

Testing the Object Selection Tool in Photoshop 2020

The Object Selection Tool lets you draw a rough rectangle or lasso around a subject and have Photoshop figure out the precise edges automatically, powered by Adobe Sensei. Three real test images — people against a plain wall, a group of pelicans with nearly identical edges, and a woman in a busy, similarly-colored background — show exactly where this tool excels and where it still needs manual help.

Getting Started with the Object Selection Tool

The tool lives inside the same dialog as several other selection tools, and switching between drawing modes is quick.

1. Open Select and Mask

   Go to Select > Select and Mask, then press W to switch to the Object Selection Tool. Choose either the rectangle or lasso mode — both work about the same, they just differ in how you draw the rough area around your subject.

Example One: A Subject Against a Plain Wall

The first test is close to ideal conditions — a subject standing against a plain white wall, with other people nearby who need to stay untouched.

2. Draw a Rough Rectangle Around the Subject

   With Object Subtract enabled, drag a rectangle loosely around the subject, even if it catches part of another person nearby. The tool is smart enough to isolate just the intended subject from that rough area.

3. Refine with Alt/Option to Subtract Detail

   Hold Alt/Option and draw over any small areas the tool incorrectly included, like a stray bit of background, to subtract them from the selection.

Where This Selection Still Needed Manual Cleanup

Output to a layer mask and the result held up well overall, but the edge around detail similar in color to skin — like part of a dress — needed manual correction. Painting black onto the layer mask to remove an area, then switching to white to paint the correct edge back in, closed most of these small gaps quickly. Even so, with a chunk missing from her leg, Aaron would not put the whole figure on a new background; using only the top half of the subject makes this cutout totally usable.

Example Two: Overlapping Subjects with Nearly Identical Edges

The second test is intentionally harder — a group of pelicans with almost no color difference between one bird and the next, making it difficult to tell where one subject ends and another begins.

4. Lasso Loosely Around the Subject

   Switch to lasso mode and draw loosely around the pelican you want to select, adding more detail with additional lasso strokes and holding Alt/Option to exclude background wherever the tool needs help.

Getting a Cleaner Edge with the Pen Tool

For a quick mockup, the automatic result is genuinely usable. For professional or portfolio work, the edge came out slightly jagged. To get a cleaner one, click the layer mask, go to Window > Properties and bring Density down a little so you can see behind the mask. Trace a clean outline around a detail like the bird’s beak with the Pen tool, right-click, choose Make Selection and feather it by about 0.4 pixels, then bring Density back up. Go to Select > Inverse so the selection covers the part to hide, and press Shift + Delete to fill it with black on the mask. That produced a noticeably cleaner edge than the automatic tool alone.

Example Three: A Subject in a Complex, Similarly-Colored Scene

The third test pushes the tool further still — a subject where the surrounding colors are close enough to her own that separating the two is genuinely difficult.

5. Draw a Rectangle and Refine with Lasso

   Start with a rough rectangle around the subject, then switch to lasso mode and hold Alt/Option to subtract unwanted elements, like another person’s hand caught in the selection. Hold Shift to add missed areas, like a bit of shirt fabric the rectangle didn’t fully capture. Part of the hand would not subtract, which is fine: after outputting to a layer mask, circle what is left with the regular Lasso Tool and press Shift + Delete to fill it with black on the mask.

Where the Refine Edge Brush Struggles Most

The Refine Edge brush inside the Select and Mask dialog is built for exactly this kind of detail work, and it does try to separate hair strands from a busy background — but on genuinely difficult hair-and-background combinations, it visibly struggles to get a clean separation, which is where a manual approach with tools like precise, channel-driven object masking still outperforms the automatic tools.

When to Rely on the Object Selection Tool vs. Manual Refinement

Across all three examples, the pattern held steady: the plainer and more contrasty the background, the better the automatic result, and the busier or more similar in color the background gets, the more manual cleanup is worth the extra time. For quick mockups or testing whether a composite idea works at all, the Object Selection Tool alone is often enough. For client work or portfolio pieces, pairing it with the Pen tool or a dedicated hair-cutting technique still produces a noticeably cleaner result, and it fits naturally into a broader background changing and removing workflow once the subject is fully isolated.

Why This Approach Works

The Object Selection Tool uses Adobe Sensei, Adobe’s artificial intelligence, to work out the edges inside a rough boundary you draw, so it only has to refine an area you’ve already pointed it toward. In all three tests it did best where the subject stood out clearly from the background, which is why edges made of similarly-colored detail, like hair against a textured background, remain the hardest case for any automatic tool to solve well. For a closer look at how the companion Select Subject tool handles that same trade-off, this look at cloud-processing improvements to Select Subject is a useful comparison.

Final Thoughts

The takeaway across all three tests is consistent: this tool genuinely speeds up the rough cutout stage, but the final edge quality still depends on how much contrast exists between subject and background. Plain backgrounds get you most of the way there in seconds; busy or similarly-colored ones still benefit from a manual pass before the result is ready for client or portfolio use. Treating the Object Selection Tool as a fast first draft, not a finished cutout, is what makes it genuinely useful rather than a shortcut that creates more cleanup work later.

Quick Reference: Keys, Menus and Settings

• Open the toolSelect > Select and Mask, then W
• Set it upMode: Rectangle or Lasso; Object Subtract on
• SubtractAlt/Option + drag over what doesn’t belong
• Check the edgeOutput To: Layer Mask, then Shift-click the mask
• Cleaner edgeWindow > Properties, lower Density; Pen tool path, right-click > Make Selection, feather about 0.4 px
• Fill the mask blackShift + Delete (Shift + Backspace)
• Add to the selectionShift + drag around what was missed