A thumbnail is a 16:9 still with one idea. The deep-imager AI image generator should compose for that, not for a poster you crop.
Ratio, face or object, then one color pop.
What is the first setting for a YouTube thumb?
16:9 in the AI image generator before any text to image prompt.
A 1:1 crop will slice faces on the left-right thirds.
Should the first credit be Nano Banana or GPT-4o image?
Nano Banana for volume; GPT-4o image if the thumb includes large title type.
Midjourney-style if the channel look is cinematic stills.
How do you iterate expression without a new scene?
Image to image: same composition, “wider eyes, reder jacket, keep 16:9.”
That spends a second credit instead of gambling a new text to image.
How many thumbs can 10 credits cover?
About five A/B pairs, or ten first drafts. Basic is $1/month for those 10 credits.
5 free credits are a single video test. Stills often return in 30 seconds–2 minutes.
Start in text to image or image to image, pick a model such as GPT-4o image, then check pricing from $1/month and how credits work before a long run.