We’ve all wished we could remove people from a busy scene or, conversely, populate a quiet one, whether during a shoot or in post-production. Discover how Photoshop can help you control pedestrian traffic in your images.
Every photographer has faced the dilemma of waiting for a scene to clear or, conversely, wishing for more people to liven up a shot. One standard solution is using a neutral density filter, which allows for extended exposures of several seconds or minutes. This technique makes passersby and moving objects disappear, though a tripod is essential.
Another approach, besides long exposure, involves taking multiple shots of the same scene with varying levels of activity. Whether the camera is tripod-mounted or handheld, post-production in Photoshop can then combine these images to create a seamless result. This allows for either the complete removal of all traces of people, creating a deserted look, or the illusion of a bustling, very busy space.
Before merging images in Photoshop, it is essential to harmonize their density, contrast, and color.
Consistent Framing and Processing
To ensure visual harmony, all photos must maintain consistent density, contrast, and colorimetry. Any inconsistencies should be rectified during post-production. For optimal results, select at least two images. There is no upper limit, but please note that including more images will increase processing time. It is crucial for the framing to be similar, if not identical, across all chosen shots. This consistency allows for effective overlapping views, which can be utilized to either remove passersby or, conversely, create a bustling scene. When capturing your images, take multiple shots. This provides greater flexibility in selecting the most suitable photos for your project.
Layer stack in Photoshop
To open images as layers in Photoshop from Lightroom, right-click and select “Edit in > Open as Layers in Photoshop.” Suppose you are working with a large number of images or have a less powerful computer. In that case, you can optimize performance by adjusting Lightroom’s external editing preferences to TIFF, Adobe RGB, 8 bits, and 300 dpi. Otherwise, it is generally recommended to use ProPhoto space and 16 bits when feasible.
Aligning layers
In Photoshop, select all layers (Select>All Layers) and then align them (Edit>Auto-Align Layers) in auto mode, without lens correction. You can disable/enable each layer to check that the alignment is correct. If there is a noticeable misalignment, you can delete a layer or adjust it manually.
Layers are stacked in order of selection in Lightroom. The first item in the list is placed at the top of the stack, and the last item is placed at the bottom. You can rearrange the layers if necessary. Then select all the layers to align them. All layers are selected manually or via the Select > All Layers menu.
The layers are aligned (Edit > Auto-Align Layers) in auto-projection mode, without checking the lens correction options.
The automatic projection mode is ideal for aligning images with identical or slightly different framing. Lens corrections are not needed because they are already done in the Lightroom development module.
Converting layers to smart objects
To automatically remove passers-by in an image, provided their positions don’t overlap between layers, follow these steps:
- Select all layers.
- Convert them into smart objects: > Smart Objects > Convert to Smart Object.
- Change their stacking mode: Layer > Smart Objects > Stack Mode > Median.
This process will make moving subjects disappear. If any visible traces of passers-by remain due to overlap (e.g., a partial body), you will need to manually edit the layers and use masks to erase the characters.
Layers are converted to smart objects
While the Median stacking mode typically removes subjects not common to stacked images, ghost images persist in our case due to overlapping passersby. Therefore, manual intervention with masks will be necessary.
Stacking with masks
To create masks, go back to the stage where all layers are stacked and aligned. For each layer, except the bottom one (which acts as the base and remains unmasked), add a black mask by selecting the layer and choosing Layer > Layer Mask > Hide All. This action automatically fills the masks with black. Then, using the brush tool with a white foreground color, brush over the mask of the layer directly above the base layer to remove passers-by. Continue this process with additional brush strokes as needed on the masks of the upper layers.
Creating a Deserted Scene: Removing People
To remove people from your image, you will use layer masks. Add black masks: for each layer, go to Layer > Layer Mask > Hide All. This will add a black mask to every layer except the bottom layer, which serves as your base. Reveal deserted areas: on each mask, paint with a white brush to selectively reveal the deserted areas from other layers, effectively replacing the passersby.
Show all passersby
If you want to make the pedestrians in each image visible, you can do so in a similar way, but with white masks associated with the layers. Select Layer>Layer Mask>Reveal All. But this time, paint over the pedestrians in black so that they appear in each of the masks of the layers above the base. Masking is challenging for pedestrians whose bodies overlap with those of others. However, Photoshop’s selection tools, such as the Object Selection tool, make it easy to detect contours.
To reveal the pedestrians, we follow a similar process. We add a white mask to each layer by selecting Layer > Layer Mask > Reveal All. Then, we paint black on the masks for each passerby, effectively replacing them with an empty area. The layers are aligned, ensuring that each character is seamlessly integrated into the image without any offset from the other pictures in the layer stack.
Discover the photography courses at Spéos
Spéos offers various training courses ranging from simple one-week photography workshops (initiation and advanced level) to 3-year courses. The long courses to become professional photographers allow you not only to master all the photographic techniques and its vocabulary (blurs, hyperfocus, sharpness zone, depth of field, backlighting, focal length, shutter release, autofocus, wide-angle, rule of thirds, etc.), but also all the stages of shooting and image processing.
Visiting the school allows you to discover the premises, the studios and the equipment, and is undoubtedly the best way to familiarize yourself with your future way of working. This is why, in addition to the open days, Spéos offers throughout the year personalized visits by appointment to come and discover the school with a member of the team.
Text and photos: Philippe Bachelier, teacher of Printing techniques at Spéos