A quote who's author I can't recall and will paraphrase is that the only difference between porn and art is the lighting.

Quality and intent. I agree that Art generally is of a higher quality technically, but there are times when the artist chooses to use a lower quality technique because his or her vision or message is best served by that lack of refinement. At the same time, there are many high quality images shot in the porn world.

There has also been the arguement that Art is sensual not sexual in nature. I think that's simply an escape into political correctness. Shooting the human form, clothed or unclothed, is inherently sexual to someone. There is nothing wrong with provoking arousal in the viewer—it's going to happen with someone, somewhere who views the image. So basically, the image is defined by it's intended purpose and the current social situation.

Shooting an orgy may for the purpose of documenting a sub-cultural event is different than shooting that same orgy to get someone off looking at a gangbang. Even if it is for the purpose of documentation - society may still label it as being pornographic. Pornographic images of the past seem quaint and innocent compared to today's exposure and acceptance of various sex acts.

I think porn falls under this current regulation:

www4.law.cornell.edu/uscode/...00-.html

(A) Except as provided in subparagraph (B), “sexually explicit conduct” means actual or simulated—

(i) sexual intercourse, including genital-genital, oral-genital, anal-genital, or oral-anal, whether between persons of the same or opposite sex;
(ii) bestiality;
(iii) masturbation;
(iv) sadistic or masochistic abuse; or
(v) lascivious exhibition of the genitals or pubic area of any person;

(B) For purposes of subsection 8(B) [1] of this section, “sexually explicit conduct” means—
(i) graphic sexual intercourse, including genital-genital, oral-genital, anal-genital, or oral-anal, whether between persons of the same or opposite sex, or lascivious simulated sexual intercourse where the genitals, breast, or pubic area of any person is exhibited;
(ii) graphic or lascivious simulated;
(I) bestiality;
(II) masturbation; or
(III) sadistic or masochistic abuse; or
(iii) graphic or simulated lascivious exhibition of the genitals or pubic area of any person;

very very true, however, for me, for those images to even be thought of as erotic, i need to have sex-itis, or sex on the brain. cuz if i dont, hmmmmm.... its just a train going into a tunnel. but the moment my mind starts to go into the gutter, ANYTHING can and does seem dirty.

I'll leap into the abyss...

When I started doing my erotic work over 10 years ago, I specifically rejected any difference between porn and erotica. In my experience, porn is erotica you don't think people would approve of and erotica is porn you think they will.

Another definition that I use is that I'm artist, because pornographers make money.

I just know what I like and what I don't. Really, the labels are just ways oneself feel more socially acceptable when in fact you probably really aren't, anyway.

I call my stuff Fine Art Pornograpy - go visit IntimateArts.com, visit the galleries and see.

If you're going to do the etymology thing, then pornography (porne + graphos) is literally the writing of prostitutes.