Objective vs subjective judgments

An objective person will make a judgment independently of their personal interest. If they aren't distant from the judgment, they're subjective or biased.

• Being biased comes in degrees. Some may have too much interest in the issue.
• The process by which one forms the judgment might be biased if one was inappropriately, unfairly, or irrationally influenced.

If by saying "ethics is subjective", you mean everyone's ethical judgments are always biased, it may be false.