The `127 Hours` actor - who is to host this year`s Oscars ceremony alongside Anne Hathaway - says appearing in a raunchy home movie made him have more respect for porn stars because he knows from personal experience how hard it is.
Speaking in a discussion held by Newsweek magazine for potential Oscar-nominees, James said: "I think if anybody who has made a home sex tape knows, what feels best doesn`t always look best. I remember when I was 19 doing that, and then watching it back and thinking, `Oh, that looks horrible.` You have a lot of respect for those actors in pornography, because they are really not just doing it, they`re really selling it."
This is not the first time James - who has been in a relationship with actress Ahna O`Reilly since 2006 - has been so open about his personal life.
Last year he revealed he masturbates "four or five times a day" because he is alone a lot.
He said: "I spend a fair amount of time alone, especially when I travel for work or whatever, but I`m in hotels a lot for a lot of my life. So, when I`m alone, I do masturbate a lot. I don`t know why. It`s like you have those days where it`s just like, I have a ton of writing to do, or a ton of reading to do, and you`re just like, OK, I`m going to be on the couch all day or in bed all day just doing that. I tend to have a four- or five-time day."