2.1 Introduction to Photoshop

Adobe Photoshop is a professional raster graphics editor used to create, edit, retouch and combine digital images made of pixels. First released in 1990, it has become the industry-standard image editor for photographers, graphic designers, architects and interior designers, and it is now offered mainly through Adobe Creative Cloud subscriptions on Windows and macOS computers, with lighter versions for tablets and the web. In interior design practice, Photoshop is the main tool for improving photographs and renders, building photo-realistic mood boards and presentation boards, and showing clients how a space will look with new colours, finishes and furniture. Example: an interior designer refurbishing a doctors' lounge at a private hospital photographs the existing room, then uses Photoshop to change the wall colour, replace the flooring and add new sofas, so the board of directors can compare the "before" and "after" views.

Uses of Photoshop in interior design

• Photo retouching: Correcting brightness, colour and perspective in site and project photographs.
• Render post-production: Adding lighting effects, people, plants, sky views and atmosphere to 3D renders.
• Before-and-after visualisation: Showing proposed colours, materials and furniture on photographs of the existing space.
• Mood boards and material boards: Combining images, textures and colour swatches into one composition.
• Coloured plans and elevations: Adding colour, textures and shadows to CAD drawings for presentation.
• Texture creation: Preparing seamless textures, such as wood, fabric and stone, for 3D rendering.
• Portfolio and marketing images: Enhancing photographs of completed projects for portfolios and social media.

Key capabilities of Photoshop

Advantages of Photoshop for interior designers

• Industry standard: Widely used, so files and skills are accepted by clients, studios and printers.
• Powerful image editing: Handles complex photo editing and compositing with high quality.
• Non-destructive editing: Layers, masks and adjustment layers allow changes without damaging originals.
• Extensive resources: Many tutorials, brushes, textures and plug-ins are available.
• Integration: Works well with other Adobe programs and common 3D rendering software.

Limitations of Photoshop

• Subscription cost: Ongoing payments can be expensive for students and small studios.
• Steep learning curve: The many tools and options take time to master.
• Hardware demands: Large files need a powerful computer with plenty of memory.
• Raster-based: Not ideal for logos, signage and line work that must scale, which suit vector programs.
• Large file sizes: Layered files take up a lot of storage space.

Steps for starting Photoshop and creating a new document

1. Launch Photoshop: Open it from the Start menu, the Dock or the Creative Cloud app.
2. View the Home screen: See recent files, learning resources and options to create or open files.
3. Click New file: Open the New Document dialog box.
4. Choose a preset or custom size: Select a print preset such as A3, or enter width, height and units.
5. Set the resolution and colour mode: Choose about 300 pixels per inch for print or 72 to 150 for screen, and RGB colour.
6. Name the document: Type a clear name for the file.
7. Click Create: The blank canvas opens, ready for work.

Key Photoshop terms for beginners

• Canvas: The working image area.
• Pixel: The tiny coloured square that makes up the image.
• Layer: A separate level of image content stacked with others.
• Selection: An area chosen for editing, shown by a moving dotted outline.
• Smart object: A layer that keeps the original image data so it can be resized without quality loss.
• History: The record of recent actions that can be undone.