(as) plain as a pikestaff informal simile
Very clear or obvious; very simple to comprehend
It's plain as a pikestaff that he stole my money. The camera recorded his attempt to break into my store.
My explanation is plain as a pikestaff, so you should solve it as soon as possible.
It's as plain as a pikestaff that he likes you. He keeps flirting with you.
State something in a very strong, clear and effective way
1. Used to describe something very clear or transparent
2. Used to describe something very understandable, especially in an ironic way to mean the opposite
1. No one has an idea.
2. It is unquestionably true, certain, or certain that; it is clear that.
To appear apparently or obviously
It was often said by a photographer when he would like small children to look at the camera and smile before he took a photo.
When the photographer said “watch the birdie”, all of us looked at the camera and smiled.