【プロンプト無料】実写ポートレートの透明感を出す検証：Airy Filter Moment（スマホフィルター・エアリー）

［26/5/17］有料ゾーンを大幅に拡充しました．ですがプロンプトと基本作例は、いっさいこれまでと変わらず、すべて無料でご覧いただけますので、どうぞご安心ください．

どうも、ナギ＠還暦です． ご訪問ありがとうございます．
還暦の今、高校時代の黒歴史を生成AIで上書きしようと、
試行錯誤しています．

AI画像生成で、スマホのフィルターを通したような
「透明感のある実写ポートレート」
を作りたいと思い、プロンプトを試行錯誤しました。

この記事では、独自プロンプト
Airy Filter Moment（スマホフィルター・エアリー）
を使い、最新のAIモデルで
どんな画像が出るか検証しました。

この記事で学べること

• imagen4 / nano banana 2 / nano banana pro の描画性能の違い

• エモい質感を再現するための**「構造化プロンプト」**の具体的な書き方

• カフェ、川べり、美術館など、シチュエーション別の出力結果と注意点

どうしても質感が硬くなってしまう
自然なスナップ写真のような空気感が出ない
などお悩みの方へ
コピペして使えるプロンプト構成も公開しています。
日々のAIポートレイト制作に、ぜひ参考にしてください。

検証方法：
Airy Filter Moment（スマホフィルター・エアリー）のキモは、
次にあげる構造化したプロンプトのうち、
## Subject & Style の部分です．
ここを固定して、
## Environment (Setting)
## Pose & Composition
をいろいろ変えて生成しました．

まずは基本の作例をご覧ください．

## Subject & Style
* **Profile:** Japanese young woman, 21 years old, portrait
* **Aesthetic:** Bright, airy light with slightly overexposed highlights and lifted matte shadows. Modern social-media aesthetic.
* **Color:** Pastel-toned color grading inspired by smartphone filters. Warm pink skin tones, soft cyan/blue environmental tones.
* **Quality:** Slight halation around bright edges, subtle digital crispness, minimal retouching, ultra high resolution.

## Environment (Setting)
* **Location:** Sunlit terrace with white curtains or a breezy balcony. Late afternoon.
* **Atmosphere:** Clean, bright, and spacious. Soft wind blowing, creating a sense of "living in the moment."
* **Clothing:** Light, translucent fabrics (e.g., sheer white blouse, loose linen dress) that catch the light and move with the wind.

## Pose & Composition
* **Body Language:** Effortless, off-guard, and weightless. Leaning lightly against a railing or tucking hair behind an ear.
* **Action:** Mid-movement gestures like a gentle turn or a soft laugh. The body should feel relaxed, avoiding any rigid or "intended" lines.
* **Camera:** Looking at viewer, eye-level candid composition, effortless feel. Slightly off-center to create a "friend's lens" perspective.
* **Constraint:** Strictly avoid "glamour" posing. No forced S-curves or aggressive eye contact. Prioritize "airy" negative space around the subject.

コンセプト 1：休日、お気に入りのカフェで

## Subject & Style
* **Profile:** Japanese young woman, 21 years old, portrait
* **Aesthetic:** Bright, airy light with slightly overexposed highlights and lifted matte shadows. Modern social-media aesthetic.
* **Color:** Pastel-toned color grading inspired by smartphone filters. Warm pink skin tones, soft cyan/blue environmental tones.
* **Quality:** Slight halation around bright edges, subtle digital crispness, minimal retouching, ultra high resolution.

## Environment (Setting)
* **Location:** Neighborhood cafe with large, sun-drenched windows, facing East. Mid-morning.
* **Atmosphere:** Calm, cozy, and relaxed. Sunlight streams through, creating a warm glow. The interior features light wooden furniture, pale ceramic mugs, and potted green plants.
* **Clothing:** A simple, high-quality knit sweater in a soft, pale mint color. Loose-fitting denim jeans. Minimalist silver necklace. The texture of the wool catching the light.

## Pose & Composition
* **Body Language:** Natural, relaxed, and intimate. Seated at a small wooden table, perhaps near a window. Leaning forward slightly, looking towards the viewer.
* **Action:** Her hands rest on a ceramic mug (pale cyan) filled with a latte. A faint smile, as if reacting to something the viewer just said. One hand might be loosely holding a book, face-down.
* **Camera:** Slightly off-center candid composition (e.g., subject on the right two-thirds). Shallow depth of field, rendering the cafe background as a soft, creamy bokeh of light and pastel colors (pinks, blues, and natural greens).
* **Constraint:** Strictly avoid professional modeling. Her gaze should be gentle, not a piercing stare. The composition should feel spontaneous, like a snap taken over a conversation.

コンセプト 2：夕暮れ前、川べりの散歩

## Subject & Style
* **Profile:** Japanese young woman, 21 years old, portrait
* **Aesthetic:** Bright, airy light with slightly overexposed highlights and lifted matte shadows. Modern social-media aesthetic.
* **Color:** Pastel-toned color grading inspired by smartphone filters. Warm pink skin tones, soft cyan/blue environmental tones.
* **Quality:** Slight halation around bright edges, subtle digital crispness, minimal retouching, ultra high resolution.

## Environment (Setting)
* **Location:** Grassy river bank or a wide riverbank pathway. Early evening, before sunset.
* **Atmosphere:** Gentle and reflective. A mild river breeze is blowing. The wide open sky is painted in soft, pale gradient of sunset colors (pale pink, light orange, soft blue).
* **Clothing:** A light, flowing linen dress in an off-white or cream color. The hemline of the dress and loose hair strands are gently lifted by the wind. A small, simple tote bag.

## Pose & Composition
* **Body Language:** Effortless, unburdened, and spontaneous. She is walking slowly on the path, her back slightly towards the camera, turning to look back over her shoulder with a natural expression.
* **Action:** She might be tucking a few loose strands of hair behind her ear (the "breezy" effect). Her gaze is directed towards the viewer, but her whole body is in mid-motion, creating a sense of "moving in the moment."
* **Camera:** Eye-level candid shot with wide negative space (the open sky and river) creating a sense of vastness. The light is diffused, minimizing harsh shadows and maximizing the "halos" around her hair.
* **Constraint:** Prioritize the feel of wind and movement over rigid form. Avoid symmetrical composition. The focus should be on her expression, capturing a genuine, split-second connection.

コンセプト 3：現代美術館のアトリウム

## Subject & Style
* **Profile:** Japanese young woman, 21 years old, portrait
* **Aesthetic:** Bright, airy light with slightly overexposed highlights and lifted matte shadows. Modern social-media aesthetic.
* **Color:** Pastel-toned color grading inspired by smartphone filters. Warm pink skin tones, soft cyan/blue environmental tones.
* **Quality:** Slight halation around bright edges, subtle digital crispness, minimal retouching, ultra high resolution.

## Environment (Setting)
* **Location:** The atrium or a large exhibition hall of a contemporary art museum, featuring minimalist architecture, exposed concrete walls, and massive floor-to-ceiling glass paneling that lets in soft, high-angle natural light. Mid-day.
* **Atmosphere:** Quiet, intellectual, and expansive. A sense of refined silence. The sunlight diffuses beautifully within the vast interior, minimizing harsh shadows and maximizing a clean, bright, and spacious feel.
* **Clothing:** A sophisticated, high-end look that is both relaxed and structured. A monochrome outfit: an oversized, tailored blazer in an off-white or light beige wool crepe, paired with a matching, flowing wide-leg trouser. Underneath, a simple white silk knit top. Accessorized with minimal gold hoop earrings and sleek, modern leather slides.
* **Details:** The texture of the wool and silk catches the light, while the flowing lines of the trousers provide the necessary movement to feel "airy" despite being a more structured outfit. Her style is deliberately minimal but clearly expensive.

## Pose & Composition
* **Body Language:** Confident, thoughtful, and casually composed. She is standing near a large window, perhaps subtly admiring a piece of art just out of frame, or simply taking in the space.
* **Action:** A very slight, fluid movement—perhaps she is mid-stride, turning back towards the viewer with a knowing, subtle smile. Her posture is relaxed but elegant, without any forced lines.
* **Camera:** Eye-level, but using a wider lens from a slightly looser, candid distance (the "friend's lens"). The vast, minimalist architecture of the museum surrounds her, providing ample negative space and emphasizing the "airy" feel. The focus is sharp on her expression, while the architecture melts into soft, clean geometric shapes in the background.
* **Constraint:** Strictly avoid tourist-like posing. Focus on capturing the feeling of effortless confidence. The large window provides the bright light needed for slightly overexposed highlights and a matte shadow look, while her presence remains central and compelling.

コンセプト 4：週末のフラワーマーケット

## Subject & Style
* **Profile:** Japanese young woman, 21 years old, portrait
* **Aesthetic:** Bright, airy light with slightly overexposed highlights and lifted matte shadows. Modern social-media aesthetic.
* **Color:** Pastel-toned color grading inspired by smartphone filters. Warm pink skin tones, soft cyan/blue environmental tones.
* **Quality:** Slight halation around bright edges, subtle digital crispness, minimal retouching, ultra high resolution.

## Environment (Setting)
* **Location:** A curated, stylish florist's storefront on a charming street in a relaxed but sophisticated urban neighborhood. The architecture features soft, aged stucco and large glass windows. Early sunny morning.
* **Atmosphere:** Calm, fresh, and inviting. Sunlight filters through the overhead tree leaves, creating a soft, warm, dappled light.
* **Clothing:** A sophisticated but effortlessly relaxed look. A very long, flowing open-front cardigan made of a lightweight, sheer silk-cashmere blend in a soft beige color, which catches and billsows slightly in the breeze. Underneath, a simple white silk-jersey tank top. A flowing, mid-calf length accordion pleat skirt in a soft, pale cyan, providing maximum movement and light-catching potential.
* **Footwear:** Modern, minimalist leather flat slides in a soft off-white, offering comfort while maintaining a clean, sophisticated line.

## Pose & Composition
* **Body Language:** Weightless, relaxed, and gracefully spontaneous. She is in mid-stride, walking slowly past the flower display, turning slightly back over her shoulder with a genuine, gentle smile.
* **Action:** Her right hand is lightly tucked her hair behind her ear, a natural reaction to the breeze. Her left hand holds a large, naturally arranged bouquet wrapped in delicate, off-white paper. The long cardigan and pleated skirt provide dynamic but soft movement.
* **Camera:** Eye-level, candid shot (the "friend's lens"). The composition is slightly off-center, creating an organic feel and ample "airy" negative space (the light filtering through the trees). The focus is sharp on her expression, while the background melts into a soft, creamy bokeh of pastel tones.
* **Constraint:** Strictly avoid any "forced" or "glamour" pose. The key is to capture the feeling of air and movement. Every line in the composition should feel fluid and relaxed, never rigid or "square."

［ネタバレ］スマホフィルター・エアリー詳細解説

ここまでお付き合いくださり、本当にありがとうございます。

検証の過程でお話しした通り、今回はAIモデルごとの挙動に少し面白い差が見られました。生成ごとに「ガチャ」のような揺らぎはあるものの、特に imagen4 は「style」の指示を色濃く反映してくれる傾向があり、このプロンプトが持つ意図をとても素直に表現してくれていると感じます。多用しすぎると作為的になりますが、要所を絞って適用すれば、非常に効果的なアプローチになるはずです。

一方、nano banana 2 と nano banana pro は比較的近いニュアンスで出力されます。比較すると細部の緻密さや全体としてのトーンのまとまりにおいて、やはり pro の方に一日の長があるような印象を受けました。ただこれも、意図との相性があると思います。

今回ご紹介した基本プロンプトと4つの具体的なシチュエーションは、これだけでも皆さんの生成環境で「透明感のある現代的なスナップ」を楽しんでいただけるかと思います。FLOWで開発しましたので、imagenやnano bananaとの相性はよいはずです。

基本の型をそのままコピーしていただき、ご自身の好きな被写体や日常の風景に言葉を置き換えるだけでも、デジタル特有の硬さが抜けた、心地よい風が通り抜けるような一枚が出力されるのでは、と思います。

その上で、もし「なぜこの言葉を組み合わせると、スマホのフィルターを通したような独自の空気が出るのか」などご関心をもたれた方には、もう少しだけ私の個人的な研究にお付き合いいただけますと幸いです。

この先の有料エリアでは、私がかつてファインダーを覗いて街の光を追いかけていた頃の記憶と重ね合わせながら、この『Airy Filter Moment』というプロンプトの変数に込めた設計思想の裏側を、具体的な記録としてお届けします。

有料エリアに含まれる内容

1．コア項目三つの詳細な設計思想：
なぜこの光と色が生まれるのか、そのロジカルな解説。

2．プロンプトの有無による質感比較：
意図しないデジタル補正を防ぐための検証結果。

3．基本プロンプトを中核に据えた5つの拡張レシピ：
このプロンプトのコアに沿った展開例を、和訳付きで具体的に提示。

4．上記の整形済み全文プロンプト：
すぐにコピーして試せる5つの全文コードブロック。

5．研究の余白（使用にあたり、注意すべき点）：
AIの挙動を踏まえた、この画風が苦手とするシチュエーションへの助言。

AIを単なる自動生成ツールとしてではなく、自分の心の中にある「あの日見た光」を再現するための大切な筆として深めていきたい。そんな風に考えている方へ向けて、私のささやかな思考のプロセスを共有させていただきます。

この研究ノートが、皆さんの手元にあるプロンプトを、より自由で確かな『表現の筆』に変える一助となれば幸いです。
いただいたサポートは、これからのAIポートレイト研究の歩みを支える燃料として、大切に活用させていただきます。