What's the difference between cyanotype and ferrotype?

Cyanotype

Definition:

• (n.) A photographic picture obtained by the use of a cyanide.

Example Sentences:

Ferrotype

Definition:

• (n.) A photographic picture taken on an iron plate by a collodion process; -- familiarly called tintype.

Example Sentences:

• (1) In particular the 19th century produced images such as daguerreotype, collodion positive and the ferrotype.