Captcha has 2 levels right now: Noisy and medium. Noisy is extremely hard to read and Medium is extremely easy, so in order to improve security, it is highly recommended to have Noisy, "HIGH", and medium--3 levels, so high would be more noisy than medium, but less than "noisy". Are there more noise options for captcha?
This is a product limitation.
Currently there are only 3 noise levels for captcha, however there is an enhancement request for additional options, ER ID: TF00415312