Adobe Photoshop – Comprehensive Study Notes

Adobe Photoshop Overview

• Photoshop is a professional-grade bitmap and photo-editing application that belongs to the Adobe Creative Cloud (CC) suite.

• Widely regarded as the “benchmark” for digital image solutions in fields such as photography, graphic design, web design, advertising, animation, game art, and motion graphics.

• Designed for both raster and limited vector workflows, combining pixel-level precision with mathematically defined shapes, paths, and type.

• Supports non-destructive techniques, meaning edits can be revised or removed without permanently damaging the underlying pixels.

• Seamlessly integrates with other Adobe CC programs (Illustrator, InDesign, Lightroom, Premiere Pro, After Effects, etc.) so assets can flow across different media pipelines.

Key Terminology & Foundations

• Resolution
  • Defined as dots per inch (dpi) for print or pixels per inch (ppi) on screen.
  • Higher resolution ⇒ more detail but larger file sizes and heavier processing.
  • Formula: $\text{Resolution} = \frac{\text{Number of Pixels}}{\text{Physical Length (in inches)}}$.

• Raster (Bitmap) Graphics
  • Composed of a grid of individual pixels, each holding color information.
  • Ideal for detailed, continuous-tone imagery such as photographs.
  • Quality degrades when scaled beyond native resolution (pixelation).

• Vector Graphics
  • Constructed from mathematical descriptions of shapes (points, lines, curves, fills).
  • Infinitely scalable without loss of quality.
  • Examples: logos, icons, typography created in Illustrator.

Photoshop Interface & Home Screen (2021 or Higher)

• Upon launch, a Welcome/Home screen appears with three key panels:
  • "Create New" – quick access to document presets.
  • "Open" – browse to existing files.
  • "Recent" & tutorial thumbnails – revisit projects or launch guided lessons.

• Updates panel highlights new CC features, tips, and learning resources.

Adobe Creative Cloud Integration

• Files can be saved directly to Creative Cloud Libraries for cross-app usage.

• Shared color swatches, type styles, and graphics can sync between Photoshop, Illustrator, and InDesign.

• Lightroom round-trip editing: send RAW photos to Photoshop for advanced retouching, then return to Lightroom with layers preserved.

Creating a New Document (Step-by-Step)

1. Click "Create New" on the Home screen —or choose File ▸ New… (shortcut: Ctrl + N on Windows, Cmd + N on macOS).

2. In the New Document dialog, select a Preset Category:
   • Photo • Print • Art & Illustration • Web • Mobile • Film & Video

3. Example procedure (Print workflow):
   • Choose the "Print" tab.
   • Select Letter size (8.5 × 11 inches).
   • Confirm resolution, e.g. $300\,\text{dpi}$ for high-quality print.
   • Color Mode defaults to CMYK for print; switch to RGB for screen-based output.
   • Click Create to generate the canvas.

Placing, Opening, and Transferring Images

• Official method:

  1. Home screen ▸ Open → navigate via OS file explorer → select → Open.

• Drag-and-Drop method:
  • From Windows Explorer/Finder, drag any supported file (JPEG, PNG, PSD, RAW, etc.) onto the Photoshop Home screen or an open document.

• Recent Files method:
  • If a file thumbnail appears in the Home screen’s "Recent" list, click it to reopen instantly.

Core Editing Concepts & Non-Destructive Workflow

• Layers
  • Each element (photo, text, adjustment) sits on its own layer and can be reordered, grouped, hidden, or blended.
  • Layer Styles (fx) apply effects such as drop shadows or strokes without altering original pixels.

• Adjustment Layers
  • Non-destructive tonal and color tweaks (Brightness/Contrast, Levels, Curves, Hue/Saturation, etc.).
  • Can be masked to affect only specific regions.

• Masks & Compositing
  • Layer Mask = grayscale bitmap controlling transparency (white = visible, black = hidden).
  • Vector Mask = path-based, resolution-independent stenciling.
  • Enables complex collages, sky replacements, or selective edits.

• Color Management
  • Photoshop supports multiple color spaces (sRGB, Adobe RGB, ProPhoto RGB, CMYK, Lab).
  • Soft-Proofing simulates output devices to ensure accurate color reproduction.

• Exporting & Saving
  • Native format: PSD (preserves layers, masks, smart objects).
  • Lossy web share: JPEG (adjust quality slider).
  • Lossless transparency: PNG-24.
  • Print or archival: TIFF.
  • Quick Export As PNG/JPEG can be configured in Preferences.

Practical Workflow Example (Letter-Size Flyer)

• Step 1 – Create new $8.5\,\text{in} \times 11\,\text{in}$, $300\,\text{dpi}$, CMYK.

• Step 2 – Drag high-resolution stock photo into canvas → converts to Smart Object so scaling remains non-destructive.

• Step 3 – Add text layer using Type Tool; apply Character panel adjustments (tracking = $20$, leading = $14\,\text{pt}$).

• Step 4 – Insert Adjustment Layer ▸ Hue/Saturation to shift entire color palette; clip it to background photo only.

• Step 5 – Create Layer Mask on photo, use soft black brush at $30\%$ opacity for vignette fade.

• Step 6 – Save master as Flyer_v01.psd, then choose File ▸ Export ▸ Export As… PNG for web preview, or File ▸ Save As… PDF for press.

Ethical, Philosophical & Professional Considerations

• Truth in Imaging: Over-retouching can mislead audiences (e.g., body-shape manipulation in advertising). Ethical retouchers disclose edits or abide by industry standards.

• Copyright: Always secure proper licenses for stock imagery or obtain model releases.

• Color Accuracy: Mismanaged color profiles can waste client budget on reprints; perform calibrated monitor checks.

• Accessibility: Provide alternative text descriptions for web graphics; ensure color contrast ratios meet WCAG guidelines.

Quick Reference: Frequently Used Shortcuts & Specs

• New Document: Ctrl/Cmd + N

• Open: Ctrl/Cmd + O

• Save: Ctrl/Cmd + S; Save As: Shift + Ctrl/Cmd + S

• Undo/Redo: Ctrl/Cmd + Z (toggle); Step Backward: Alt/Option + Ctrl/Cmd + Z

• Zoom: Ctrl/Cmd + Plus/Minus; Fit on Screen: Ctrl/Cmd + 0

• Brush Size: [ ] keys; Hardness: Shift + [ ]

• Toggle Layer Visibility: Eye icon or Alt/Option + Click to solo a layer.

Connections to Other Lectures & Real-World Relevance

• Color Theory (from previous design lecture) directly informs Curves, Levels, and Color Balance adjustments.

• File Formats discussion (upcoming session) will expand on lossy vs lossless compression introduced here.

• Real-world job roles: Photographers rely on Photoshop for RAW retouching; UI designers export layered assets to XD or Figma; pre-press technicians convert RGB artwork to CMYK with soft-proofing.

Numerical & Statistical References

• Print industry standard resolution: $300\,\text{dpi}$.

• Web standard resolution: $72$–$96\,\text{ppi}$ depending on device.

• Common color bit depths: $8$-bit/channel ((2^{8}=256) levels), $16$-bit/channel ((65{,}536) levels).

• Maximum PSD dimensions (as of PS 2021): $300{,}000 \times 300{,}000$ pixels with Large Document Format (PSB).