How to Review Generated Image Artifacts for Lens Flare Placement in Nano Banana 2

When generating images with Nano Banana, a powerful AI image generation and editing tool, users often request specific lighting effects like lens flares. However, because the underlying technology relies on probabilistic models rather than physical ray tracing, these effects can sometimes manifest as visual anomalies. The goal of this review is not just to see if a flare exists, but to determine if it behaves logically within the scene or if it appears as a random digital artifact. This process ensures your final output maintains visual integrity.

It is important to clarify that Nano Banana refers strictly to the AI image generation/editing tool described here. It is not a skincare brand, bottle, jar, or any physical subject. When you generate an image, you are interacting with a model that interprets text instructions to create visual data. Understanding the distinction between a realistic optical phenomenon and a generated glitch is essential for high-quality results.

Identifying Logical Light Source Alignment

The primary criterion for judging a valid lens flare is its relationship to the light source. In real-world photography, a lens flare originates from a bright point of light entering the camera lens at a specific angle. To review your generated image effectively, first locate the brightest area in your composition. This is your theoretical light source.

Trace the path of the flare elements—streaks, hexagonal shapes, or circular glows—back toward this source. A logically placed flare will align geometrically with the light source. If the sun is positioned in the top-left corner, the streaks should extend diagonally across the frame in a consistent direction relative to that corner. If the flare appears in the bottom-right without a corresponding light source nearby, or if the streaks point away from the nearest bright object, it is likely an artifact.

Random digital artifacts often lack this directional consistency. They may appear as floating orbs, disconnected smudges, or patterns that do not follow the perspective lines of the scene. These glitches occur when the model attempts to satisfy the prompt "lens flare" without fully understanding the spatial constraints of the generated environment. By mentally simulating where a real camera would capture light, you can quickly spot these inconsistencies.

Step-by-Step Workflow for Artifact Detection

To systematically review your images for these issues, follow this structured approach. This workflow helps isolate lighting problems from other potential generation errors.

1. Isolate the Image: Open your generated image in a viewer that allows zooming to 100% or higher. This reveals pixel-level details that might be missed at thumbnail size.
2. Locate the Primary Light Source: Identify the most intense light source in the scene, such as the sun, a streetlamp, or a reflection.
3. Map the Flare Geometry: Visually connect the flare elements to the light source. Check if the angle of the streaks matches the expected optical path.
4. Check for Repetition: Look for identical flare patterns repeating in unrelated parts of the image. While some symmetry is natural, identical artifacts appearing in shadows or dark areas suggest a hallucination.
5. Compare Against Reference: If you used an image-to-image workflow, compare the lighting logic of the input image against the output. Significant deviations in flare placement that contradict the original lighting setup indicate a processing error.
6. Document Findings: Note specific coordinates where artifacts appear. This helps in refining your prompts for future generations.

Remember that Nano Banana supports both text-to-image and image-to-image workflows. The prompt library offers example prompts that users can copy or take into the generator. However, prompt instructions describe desired outcomes; they do not guarantee identity, label, object, or typography preservation. Therefore, even a well-crafted prompt might result in misaligned flares if the model struggles with complex lighting physics.

Refining Prompts and Using Model Variants

If you consistently encounter illogical flares, consider adjusting your prompt strategy. Be specific about the light source position. Instead of simply asking for "a lens flare," try "a lens flare extending from the top-left sun towards the center." This provides the model with clearer spatial context.

You may also need to select the appropriate model variant. Google documents Nano Banana 2 as Gemini 3.1 Flash Image (gemini-3.1-flash-image), while Nano Banana Pro corresponds to Gemini 3 Pro Image (gemini-3-pro-image). There is also Nano Banana 2 Lite, identified as Gemini 3.1 Flash Lite Image (gemini-3.1-flash-lite-image).

It is crucial to understand the limitations of each. Google describes Nano Banana 2 Lite as focused on speed and cost. It is not optimized for multiple reference inputs or multi-turn sequential editing. Do not recommend it for those workflows without explaining this limitation. For complex lighting scenarios requiring precise artifact control, the standard Nano Banana 2 or Pro versions may offer better fidelity than the Lite version.

Judging Results and Fixing Common Issues

How do you know if the review was successful? A successful generation will have flares that feel integrated into the scene. They should not look pasted on top. If the flare obscures important details without a logical reason, or if it creates a halo effect around objects that are not near the light source, it is an artifact.

Common fixes include:

• Re-prompting with Constraints: Explicitly state "no random flares" or "flares must originate only from the sun."
• Model Switching: Try switching from Nano Banana 2 Lite to the standard Nano Banana 2 if the Lite version produces too many uncontrolled artifacts due to its optimization for speed.
• Iterative Editing: Use the image-to-image feature to refine the lighting. Upload the flawed image and instruct the tool to "correct the lens flare alignment based on the light source."

While we cannot guarantee perfect outcomes, following these steps significantly improves the likelihood of obtaining a coherent image. For more information on the capabilities of the tool, visit Try Nano Banana. Always remember that these tools are generative, and human oversight remains the final judge of quality.

By applying these review techniques, you transform the generation process from a gamble into a controlled creative workflow. Whether you are creating marketing assets or artistic compositions, ensuring that optical artifacts like lens flares behave logically is key to professional-grade results.