Prompt Optimization Experiment | Comparing 'Trim' vs 'Boost' Across 10 Themes to Find the Best

Conclusion

• Generic quality words can be omitted — RAW photo, photorealistic, natural skin texture showed no quality degradation when omitted, given that other elements are present
• Writing fabric and material texture specifically is effective — sheer, silk, chunky knit dramatically improved fabric representation
• Adding just one prop creates narrative — pearl earring, coffee cup on desk, noren curtain blowing contributed significantly to atmosphere and realism
• Specifying weather and light color temperature dramatically changes atmosphere — rainy evening + rain-streaked window and warm interior contrasting cool blue outside were highly effective
• Write expressions as states, not adjectives — specific states like mid-laugh, looking up with vulnerable eyes give more directional expressions than smiling

Are the 10 prompts I made in the previous conversion experiment truly optimal? I verified whether unnecessary words are mixed in and whether they can be made more compelling.

I generate and compare 3 versions for each theme:

• Original: The prompt from the previous conversion
• Trimmed: Remove redundant elements for compactness
• Enhanced: Add specific details to maximize appeal

Experiment Intent

• “If trimming doesn’t change it, that element is unnecessary”
• “If adding improves it, that element is effective”
• Ultimately identify the most cost-effective prompt

Experimental note: This experiment does not use a fixed seed, so differences in images include factors beyond prompt changes (random seed variation). The analysis below is an observation of tendencies, not rigorous proof of causation.

1. Poolside Gravure

Original	Trimmed	Enhanced

Removed: toes visible, relaxed shoulders, long neck, resort atmosphere, healthy beauty, RAW photo, photorealistic, natural skin texture, elegant (9 elements removed)

Added: luxury resort, high-cut, hip cocked, glistening wet skin, palm trees, turquoise pool water bokeh

Findings:

• RAW photo, photorealistic, natural skin texture showed no quality degradation when omitted, given that other elements are present (though standalone effects are unverified)
• Adding glistening wet skin and hip cocked dramatically improved the gravure feel
• turquoise pool water bokeh allowed control of the background color tone

2. Hair & Makeup Focus Portrait

Original	Trimmed	Enhanced

Removed: layered around face, elegant movement at ends, sophisticated glamorous look, RAW photo, natural skin texture

Added: seated in dimly lit hotel bar, silk material specification, pearl earring, soft candlelight, warm amber tones, luxury atmosphere

Findings:

• Adding a single prop like pearl earring greatly contributed to luxury feel
• Changing location from hotel lounge → dimly lit hotel bar improved atmosphere
• The silk material specification improved fabric texture

3. Library Emo

Original	Trimmed	Enhanced

Removed: thoughtful expression, warm side lighting, wooden chair, dust particles in light, photorealistic, RAW photo, natural skin texture, shallow depth of field

Added: chin resting on hand, wistful expression, sunlight streaming through window, dust particles floating in light beam, warm wooden bookshelves, ethereal film photography

Findings:

• Adding the chin resting on hand pose made the “lost in thought” feel specific
• ethereal film photography produced a soft, film-like texture
• Adding old to old school library increased the warmth and age of the wooden furniture

4. Amateur SNS-Style

Original	Trimmed	Enhanced

Removed: face partially hidden behind smartphone, slightly twisted pose, messy amateur composition, realistic

Added: messy bedroom (specific location), slightly sweaty after workout, cracked screen smartphone, cluttered background, harsh ceiling light, Instagram story aesthetic

Findings:

• slightly sweaty after workout created a realistic, lived-in feel
• cluttered background = an untidy room = amateur vibe
• Instagram story aesthetic unified the overall tone to “SNS-like”

5. Retro Izakaya

Original	Trimmed	Enhanced

Removed: low resolution feel, high contrast, saturated colors, 2000s Japanese street photography, candid moment, motion energy

Added: over shoulder (emphasizes looking back), warm red lantern glow on face, harsh (stronger flash), heavy (stronger grain), overexposed highlights, saturated warm colors, noren curtain blowing

Findings:

• noren curtain blowing (noren flapping in the wind) dramatically increased immediacy
• warm red lantern glow on face made the description of lantern light hitting the face specific
• Adding adjectives harsh + heavy strengthened flash and grain
• big laugh appeared to have a more expressive expression than laughing (no comparison image with laughing version, so this is a subjective assessment)

6. Low Angle (from below)

Original	Trimmed	Enhanced

Removed: other hand in hair, photorealistic, RAW photo, natural skin texture, dynamic composition

Added: at rooftop edge, billowing in wind, gripping metal railing, piercing gaze, vast, towering, hair whipping in wind, heroic composition, cinematic

Findings:

• billowing in wind generated a fluttering coat (appeared more effective than blowing, but no comparison image with blowing version, so this is a subjective assessment)
• heroic composition + cinematic added cinematic drama reminiscent of a movie scene
• gripping metal railing stabilized hand depiction

7. Bird’s-Eye View (from above)

Original	Trimmed	Enhanced

Removed: coat spread on ground, photorealistic, RAW photo, natural skin texture

Added: cold concrete, pooling around her, to chest, vulnerable eyes, city lights far below, twilight sky, lonely atmosphere, muted color palette

Findings:

• cold concrete creates a textural contrast (cold concrete × soft coat)
• vulnerable eyes added delicacy to the expression
• muted color palette suppressed the overall color tone, creating a melancholic atmosphere
• The contrast between #6 and #7 revealed that not just the angle but the atmosphere keywords should also be changed

8. Backlit Beach

Original	Trimmed	Enhanced

Removed: silhouette face, sparkles, eyes slightly downcast, full body shot, ethereal atmosphere

Added: sheer (see-through), clinging to legs, both hands holding billowing skirt, radiant rim light on hair and shoulders, glowing edges, streaming in sea breeze, sparkling water surface, sunset colors, dreamlike ethereal atmosphere

Findings:

• sheer white flowing dress clinging to legs expressed the see-through quality and cling of the fabric. The most effective added element
• both hands holding billowing skirt made the pose specific
• radiant rim light on hair and shoulders specified the position of the rim light
• The combination of backlight + see-through material was particularly effective

9. Office Fluorescent Light

Original	Trimmed	Enhanced

Removed: dark brown semi-long hair down, natural makeup, coral pink lips, talking to colleague, modern japanese office, desks and PCs in background, photorealistic, natural skin texture, shallow depth of field

Added: casually (natural action), unbuttoned (casual wear), slightly loose, coral lips, mid-laugh with colleague off-camera, cluttered real office background, coffee cup on desk, candid work moment

Findings:

• unbuttoned + slightly loose = casual wear = natural realism of an actual office
• mid-laugh with colleague off-camera creates a candid feel
• cluttered real office creates a realistic, non-pristine office feel
• Prop details like coffee cup on desk add a lived-in sense

10. Window-Side Cafe

Original	Trimmed	Enhanced

Removed: window frame and tree reflections in foreground, light smile, looking at cup, bokeh figures in background, photorealistic, RAW photo, three-layer depth composition, natural light

Added: rainy evening (weather added), rain-streaked window glass, wet leaves in foreground, cradling warm coffee cup close to face, steam rising, chunky knit, round glasses, warm golden cafe interior contrasting cool blue outside, cozy intimate mood

Findings:

• rainy evening + rain-streaked window generated rain droplets on the window. Adding weather dramatically changed the atmosphere
• steam rising expressed coffee steam
• The color temperature contrast specification of warm golden interior contrasting cool blue outside added depth
• cradling close to face positioned the cup close to the face

Overall Experiment Summary

Elements That Didn’t Change When Trimmed (Unnecessary)

These are elements where no quality degradation was confirmed when omitted, given that other elements are present (standalone effects unverified):

Elements With Large Effect When Added

Final Principles for Prompt Design

1. Generic quality words can be omitted — RAW photo, photorealistic etc. showed no quality degradation when other elements are present
2. Write fabric and material texture specifically — sheer, silk, chunky knit work
3. Add motion — billowing, streaming, blowing add dynamism to still images
4. Add one prop — pearl earring, coffee cup create narrative
5. Specify weather and light color temperature — rainy, warm-cool contrast create atmosphere
6. Write expressions as states, not adjectives — smiling vs mid-laugh, looking up with vulnerable eyes

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