This article helps you pick the right AI model for your prompt, and explains why AI photos can be slow, fail, or look different from before. You choose the model (AI Engine) for each prompt in AI Studio, and the credit cost per model is in the AI Credit FAQ.
Which model should I choose?
Best detail and likeness: Nano Banana Pro 2K.
Faster, still good quality: the 2K (non-Pro) Nano Banana model.
Large prints (for example 8.5x11): a 4K model. Try both and see what works best for your prompt.
Prompts written by ChatGPT or similar tools: try an OpenAI model. These prompts are often long and include lots of "No XYZ" lines, and Nano Banana does not handle negative instructions well. You can also ask Booth.Bot to rewrite the prompt to suit Nano Banana.
Why does the same prompt give different results now?
The image models are run by Google and OpenAI, and they update them from time to time. An update can change how an existing prompt behaves. If an old prompt no longer looks right, try another model, or add one of your earlier results as a reference image and ask Booth.Bot to recreate its style.
Why is my AI photo slow or showing an error?
Render speed is controlled by the model provider, not by Booth.Events. Pro models are usually slower, and when traffic on the provider's side is heavy, generations can take longer or occasionally fail. A slow internet connection at your event will also cause problems, so run a speed test on the iPad. If you get an error about the content, the model provider (for example Gemini) may have blocked it: this happens with images of celebrities, copyrighted characters or logos (IP), or unsafe content.
Common questions
Is Pro always better?
No. Pro is better at likeness and realism but slower. Test both for your prompt.
Do I need 4K?
Only for specific needs such as larger prints. 2K is enough for great digital and printed photos.
Why did my photo come out the wrong shape?
The original Nano Banana model does not always respect your template's aspect ratio. Use a Pro model if the shape matters.