Prompt Engineering Tutorial for Nano Banana

By Example — with Real Prompts and Outputs

Prompt at https://gemini.google.com/

Google Nano Banana (like MidJourney, DALL·E, or Stable Diffusion) responds to highly descriptive prompts. The more structured, visual, and contextual your input, the closer the output matches your intent.

Core Principles

1. Specificity Over Generality

• Vague: "a nice portrait"
• Better: "hyper-realistic studio portrait with professional lighting"

2. Visual Hierarchy

• Start with the main subject
• Add environment/background
• Specify lighting and mood
• Include technical details

3. Professional Photography Language

• Use camera terminology (85mm lens, f/1.4, shallow depth of field)
• Reference lighting setups (Rembrandt lighting, studio lighting)
• Mention photography styles (editorial, cinematic, fine art)

Anatomy of Effective Prompts

A well-structured prompt typically includes:

1. Subject Description (who/what)
2. Pose/Action (body language, positioning)
3. Environment (background, setting)
4. Lighting (type, direction, mood)
5. Style (aesthetic, genre)
6. Technical Specifications (camera settings, composition)
7. Mood/Atmosphere (emotional tone)

🔹 Example 1: Professional Branding Portrait

Prompt Used:

Original Image:

Generated:

✅ What Worked Here

• Subject grounding: “of the uploaded photo” ensures consistency.
• Pose instructions: “hands inside the pockets, leg casually crossed” avoids random posture.
• Context & setting: “smooth light-gray wall, professional studio lighting” makes it brand-safe.
• Extra elements: vector portrait + typography = personal brand identity.

💡 Takeaway Rule:For branding prompts, combine subject grounding + posture + context + design elements (like logos or text).

🔹 Example 2: Cinematic Black & White Portrait

Prompt Used:

or

Style Metadata:

• Style: cinematic, moody, introspective
• Lighting: soft side lighting, high contrast shadows
• Camera: Leica SL2-S, 85mm f/1.4, shallow DoF
• Mood: thoughtful, reflective, timeless

Generated:

✅ What Worked Here

• Mood anchoring: “moody, cinematic, introspective” frames the emotional tone.
• Photography realism: camera & lens details simulate professional photography.
• Lighting control: “Rembrandt light” + “high contrast” = timeless look.

💡 Takeaway Rule:For artistic portraits, describe mood, lighting style, and camera lens to mimic photography realism.

🔹 Example 3: Corporate Headshot

Prompt:

Generated:

✅ Why This Works: It creates a clean, realistic image suitable for resumes, LinkedIn, or official documents.

🔹 Example 4: Futuristic Branding Poster

Prompt:

💡 Use Case: Great for AI events, keynotes, or futuristic branding material.

Generated:

🔹 Example 5: Magazine Editorial Style

Prompt:

💡 Use Case: Stylish professional portfolios or publications.

Generated:

🔹 Example 6: Abstract Creative Variant

Prompt:

💡 Use Case: Event banners, creative keynote posters, or website hero images.

Generated:

📝 Best Practices for Prompt Engineering in Nano Banana

1. Anchor the Subject

   • Always mention: “of the uploaded photo” to retain likeness.

2. Control the Scene

   • Use environment cues: background, wall, lighting, props.

3. Specify Style & Mood

   • Example moods: cinematic, corporate, fine art, futuristic.

4. Borrow from Photography

   • Camera/lens terms like 85mm f/1.4 create realism.
   • Lighting terms like Rembrandt, softbox, backlight help shape mood.

5. Add Branding Elements

   • Vector logos, text overlays, geometric accents.

6. Iterate in Layers

   • Start broad (“corporate portrait”), then refine with poses, props, typography.

Advanced Techniques

1. Layered Lighting Descriptions

Primary: soft key light from camera left
Secondary: subtle fill light to reduce shadows
Accent: rim light from behind for separation
Ambient: warm studio ambiance, controlled spill

2. Composition Rules

Rule of thirds placement, subject positioned at left intersection
Leading lines from architectural elements
Negative spaceon right side fortext overlay
Shallow depth of field with bokeh background blur

3. Color Psychology Integration

Warm golden hour tones for approachability
Cool blue shadows for professionalism
High contrast blackand white for timeless elegance
Muted earth tones for organic, natural feel

Style Categories

Corporate/Professional

Creative/Artistic

Fashion/Editorial

Lifestyle/Personal Branding

Common Mistakes to Avoid

❌ Too Vague

Bad: "nice portrait of a person" Good: "professional headshot with studio lighting and neutral background"

❌ Conflicting Styles

Bad: "vintage film aesthetic with modern digital clarity" Good: "vintage-inspired styling with modern professional photography techniques"

❌ Overcomplicating

Bad: "surreal artistic avant-garde experimental abstract conceptual portrait" Good: "creative portrait with artistic lighting and thoughtful composition"

❌ Missing Key Elements

Bad: "person standing" Good: "confident business professional standing against clean white background, professional studio lighting, corporate headshot style"

Best Practices

1. Use Reference Photography Terms

• Studio lighting: key light, fill light, rim light, background light
• Natural lighting: golden hour, blue hour, window light, overcast
• Moods: dramatic, soft, high-key, low-key, moody, bright and airy

2. Specify Camera Equipment When Needed

Shot with professional DSLR camera85mm portrait lens for flattering compression
f/2.8 aperture for subject separation
ISO 100for maximum image quality

3. Include Environmental Context

Modern corporate office environment
Clean white seamless backdrop
Urban rooftop with city skyline
Natural outdoor setting withsoft shadows

4. Layer Your Descriptions

Start broad, then add specifics:

1. Subject type: "Professional business portrait"
2. Add specifics: "of a confident executive"
3. Include environment: "in a modern office setting"
4. Specify lighting: "with soft natural window light"
5. Add technical: "shot with 85mm lens, shallow depth of field"
6. Define mood: "conveying leadership and approachability"

5. Use Structured Formatting

Method 1: Paragraph Style

Method 2: Categorized Style

Method 3: JSON Structure (for complex requirements)

{
  "subject": "professional business portrait",
  "pose": "confident standing position, direct gaze",
  "environment": "modern corporate office",
  "lighting": {
    "primary": "soft natural window light",
    "secondary": "subtle fill lighting"
  },
  "camera": {
    "lens": "85mm",
    "aperture": "f/2.8",
    "style": "professional headshot"
  },
  "mood": "confident, approachable, executive presence"
}

Advanced Example Templates

Template 1: Corporate Executive

Template 2: Creative Professional

Template 3: Lifestyle/Personal Brand

Quality Control Checklist

Before submitting your prompt, verify:

• [ ] Subject is clearly described
• [ ] Pose/positioning is specific
• [ ] Lighting type and direction are specified
• [ ] Environment/background is detailed
• [ ] Camera/technical specs enhance the vision
• [ ] Mood and style are clearly communicated
• [ ] No conflicting elements
• [ ] Professional photography language is used
• [ ] The prompt flows logically from main subject to details

Conclusion

Effective prompt engineering for nano banana combines artistic vision with technical precision. By following these principles and studying the examples provided, you'll be able to consistently generate professional-quality portraits that meet your specific requirements. Remember: specificity, structure, and professional photography terminology are your keys to success.

Practice with these templates, adapt them to your needs, and develop your own style of prompt engineering. The more specific and well-structured your prompts, the better your results will be.

Appendix A: Professional Photography Language Reference

A Comprehensive Guide to Photography Terminology for AI Image Generation

Usage Guidelines for AI Prompts

Combining Technical Terms

Example Structure: "Professional portrait shot with 85mm lens at f/1.4, creating shallow depth of field with creamy bokeh. Rembrandt lighting setup using softbox as key light, subtle fill light to control shadows."

Balancing Technical and Creative

• Use 2-3 technical terms per prompt maximum
• Combine with creative descriptors for mood
• Prioritize terms that affect the final aesthetic
• Avoid conflicting technical specifications

Common Effective Combinations

Corporate Professional:

• "85mm lens, f/2.8, even studio lighting, neutral background"

Artistic Portrait:

• "Shallow depth of field, dramatic side lighting, black and white, high contrast"

Environmental Portrait:

• "35mm lens, natural window light, environmental storytelling, documentary style"

This appendix serves as a reference guide for understanding and effectively using professional photography terminology in both traditional photography and AI image generation prompts.

Camera Equipment & Technical Specifications

Lenses & Focal Lengths

Portrait Lenses (85mm-135mm)

• 85mm lens: The gold standard for portraits; provides natural perspective with subtle compression
• 105mm lens: Slightly more compressed than 85mm; excellent for isolating subjects
• 135mm lens: Maximum compression for dramatic effect; requires more distance from subject

Standard Lenses (35mm-50mm)

• 50mm lens: "Normal" lens that mimics human vision; versatile for environmental portraits
• 35mm lens: Wider field of view; good for environmental storytelling and context

Wide Angle Lenses (14mm-35mm)

• 24mm lens: Wide perspective; can create dramatic environmental context
• 35mm lens: Moderate wide angle; includes more environment without distortion

Aperture Settings (f-stops)

Wide Apertures (Shallow Depth of Field)

• f/1.4: Maximum background blur (bokeh); extremely shallow focus
• f/1.8: Strong subject isolation; creamy background separation
• f/2.8: Good separation while maintaining some background context

Medium Apertures (Balanced Focus)

• f/4.0: Moderate depth of field; good for environmental portraits
• f/5.6: Standard portrait aperture; sharp subject with blurred background

Narrow Apertures (Deep Focus)

• f/8.0: Sharp focus throughout most of the frame
• f/11: Maximum sharpness across the entire image

Camera Types & Formats

Professional DSLR/Mirrorless

• Canon 5D Mark IV: Full-frame professional camera
• Sony A7R IV: High-resolution mirrorless system
• Nikon D850: Professional DSLR with exceptional detail

Medium Format

• Hasselblad: Premium quality with distinctive look
• Fujifilm GFX: Modern medium format digital

Film References

• 35mm film: Classic film format with characteristic grain
• Medium format film: Larger negative size for superior quality

Lighting Terminology

Studio Lighting Setup

Key Light

• Primary light source illuminating the subject
• Usually positioned 45 degrees from camera axis
• Determines the overall exposure and main shadows

Fill Light

• Secondary light that reduces shadow contrast
• Typically softer and less intense than key light
• Positioned opposite the key light

Rim Light/Hair Light

• Back light that creates separation from background
• Highlights the edge/outline of the subject
• Creates depth and dimensionality

Background Light

• Illuminates the backdrop separately from subject
• Controls background tone and separation
• Can create gradients or even illumination

Lighting Patterns

Rembrandt Lighting

• Classic portrait lighting creating small triangle of light on shadow side of face
• Key light positioned high and to one side
• Creates dramatic, artistic mood

Butterfly Lighting

• Light directly in front and above subject
• Creates butterfly-shaped shadow under nose
• Flattering for most face shapes

Split Lighting

• Light positioned 90 degrees to side of subject
• Half the face in light, half in shadow
• Creates dramatic, moody effect

Loop Lighting

• Slight variation of Rembrandt with softer shadows
• Small shadow loop from nose on cheek
• Natural, flattering look

Light Quality Descriptions

Hard Light

• Direct, undiffused light source
• Creates sharp, defined shadows
• High contrast between highlights and shadows
• Example: Direct sunlight, bare flash

Soft Light

• Diffused or bounced light source
• Gradual transition between light and shadow
• Even, flattering illumination
• Example: Overcast sky, softbox, umbrella

Directional Light

• Light with clear direction creating modeling
• Reveals form and texture through shadows
• Creates three-dimensional appearance

Flat Light

• Even illumination with minimal shadows
• Reduces texture and dimension
• Good for eliminating imperfections

Natural Lighting Conditions

Time-Based Lighting

Golden Hour

• First/last hour of sunlight
• Warm, soft, directional light
• Long shadows and golden color temperature
• Most flattering natural light for portraits

Blue Hour

• Period just after sunset/before sunrise
• Even, soft blue-toned light
• No harsh shadows
• Romantic, moody atmosphere

Overcast

• Cloudy sky acting as giant softbox
• Even, diffused lighting
• No harsh shadows
• Consistent light throughout day

Midday Sun

• Direct overhead sunlight
• Hard, unflattering shadows under eyes and nose
• High contrast
• Generally avoided for portraits

Direction & Quality

Window Light

• Soft, directional natural light
• Size of window affects light quality
• North-facing windows provide consistent light
• Can be modified with curtains or diffusion

Backlighting

• Subject between camera and light source
• Creates rim lighting effect
• Can produce lens flare or silhouettes
• Dramatic and atmospheric

Side Lighting

• Light coming from subject's side
• Reveals texture and form
• Creates natural shadow patterns
• Good for dramatic portraits

Depth of Field Terminology

Focus Effects

Shallow Depth of Field

• Small area in sharp focus
• Background/foreground heavily blurred
• Created by wide apertures (f/1.4, f/1.8)
• Isolates subject from environment

Deep Depth of Field

• Large area in sharp focus
• Background remains recognizable
• Created by narrow apertures (f/8, f/11)
• Good for environmental context

Bokeh

• Quality of out-of-focus areas
• Smooth, creamy blur is desirable
• Affected by lens design and aperture shape
• "Good bokeh" = pleasing background blur

Focus Fall-off

• Gradual transition from sharp to blurred
• Rate depends on aperture and focal length
• Longer lenses create faster fall-off

Composition & Framing

Classic Rules

Rule of Thirds

• Frame divided into nine equal sections
• Subject positioned at intersection points
• Creates more dynamic composition than centering

Leading Lines

• Lines in image that draw eye to subject
• Can be architectural elements, natural features
• Creates depth and guides viewer attention

Negative Space

• Empty areas around subject
• Provides breathing room in composition
• Can be used for text overlay in branding

Framing

• Using elements to create border around subject
• Windows, doorways, natural elements
• Draws attention to subject

Portrait-Specific Framing

Headshot

• Cropped at shoulders or upper chest
• Focus on face and expression
• Standard for corporate and acting portfolios

Three-Quarter Length

• Cropped at mid-thigh or knee
• Shows more body language and pose
• Good balance of subject and environment

Full-Body

• Shows entire subject from head to toe
• Includes more environmental context
• Requires careful attention to posing

Environmental Portrait

• Subject shown in their natural environment
• Context tells story about person
• Balances subject with surroundings

Photography Styles & Genres

Commercial Photography

Corporate Headshots

• Clean, professional appearance
• Even lighting to minimize shadows
• Neutral backgrounds
• Conservative cropping and composition

Executive Portraits

• Authoritative and confident mood
• Higher production value
• Environmental context of success
• Premium lighting and retouching

LinkedIn Profile Photos

• Approachable but professional
• Clean background
• Direct eye contact
• Conservative business attire

Editorial Photography

Magazine Style

• High production value
• Creative lighting and composition
• Fashion-forward styling
• Artistic interpretation of subject

Documentary Style

• Natural, candid moments
• Environmental storytelling
• Authentic expressions and poses
• Less controlled lighting

Fashion Photography

• Emphasis on styling and clothing
• Creative poses and expressions
• High contrast or dramatic lighting
• Artistic composition

Fine Art Photography

Portrait Art

• Artistic interpretation over commercial appeal
• Creative use of light and shadow
• Unique perspectives and compositions
• Emotional or conceptual storytelling

Black and White

• Emphasis on form, texture, and contrast
• Timeless, classic aesthetic
• Dramatic lighting effects
• Removes color distractions

Color Temperature & White Balance

Color Temperature Scale (Kelvin)

Warm Light (2700K-3200K)

• Candlelight, tungsten bulbs
• Golden, orange tones
• Cozy, intimate feeling
• Good for romantic or comfortable moods

Neutral Light (3200K-5500K)

• Studio strobes, flash
• Balanced, natural skin tones
• Professional standard
• Most flattering for portraits

Cool Light (5500K-7000K)

• Daylight, overcast sky
• Blue-white tones
• Clean, modern feeling
• Can appear clinical or professional

Very Cool Light (7000K+)

• Shade, blue sky
• Strong blue cast
• Can create mood or technical issues
• Often corrected in post-processing

Post-Processing Terms

Basic Adjustments

Exposure

• Overall brightness of image
• Affects highlights and shadows
• Global adjustment affecting entire image

Contrast

• Difference between lightest and darkest areas
• High contrast = dramatic, punchy look
• Low contrast = soft, muted appearance

Highlights/Shadows

• Selective adjustment of bright/dark areas
• Recovers detail in blown highlights
• Opens up dark shadow areas

Advanced Techniques

Dodge and Burn

• Selectively lighten (dodge) or darken (burn) areas
• Enhances natural light patterns
• Adds dimension and modeling to face

Color Grading

• Adjusting colors for mood and style
• Separate control of highlights/shadows
• Creates signature look or brand consistency

Skin Retouching

• Removing blemishes and imperfections
• Smoothing while maintaining texture
• Professional standard varies by use case

Professional Photography Equipment

Studio Equipment

Softbox

• Fabric diffusion panel over light source
• Creates soft, even illumination
• Various sizes for different effects
• Most common studio modifier

Umbrella

• Reflective or shoot-through diffusion
• Broader, softer light than direct flash
• Portable and easy to set up
• Less controlled than softbox

Beauty Dish

• Large, shallow reflector
• Soft yet directional light
• Popular for fashion and beauty work
• Creates distinctive catch-light pattern

Grid/Honeycomb

• Restricts light spread
• Creates more directional beam
• Prevents light spill
• Good for background separation

Modifiers & Accessories

Reflector

• Bounces light back onto subject
• Fills in shadows naturally
• Available in various colors (white, silver, gold)
• Essential for outdoor portraits

Flag/Gobo

• Blocks or shapes light
• Creates shadows or negative fill
• Controls light spill
• Professional lighting control

Diffusion Panel

• Large translucent material
• Softens harsh sunlight
• Creates even illumination
• Portable solution for location work

Quality Descriptors

Image Quality Terms

Tack Sharp

• Extremely sharp focus
• No motion blur or focus issues
• Professional standard for portraits
• Requires proper technique and equipment

Creamy Bokeh

• Smooth, pleasant background blur
• No harsh edges or distracting elements
• Sign of quality lens and proper technique
• Desirable for subject isolation

Rich Tones

• Full range of colors and contrast
• No blown highlights or blocked shadows
• Professional color grading
• Premium post-processing quality

Natural Skin Tones

• Accurate color reproduction
• Proper white balance
• Flattering but realistic
• Professional standard for portraits

Professional Standards

Editorial Quality

• Magazine-ready production values
• Perfect technical execution
• Creative and engaging composition
• High-end retouching standards

Commercial Grade

• Suitable for advertising and marketing
• Consistent brand representation
• Professional lighting and styling
• Polished final presentation

Fine Art Standard

• Museum-quality printing and finishing
• Artistic vision and execution
• Unique perspective and interpretation
• Long-term archival considerations