Poser Models for all to use {Some nudity in this thread}
The problem is: complexity. Poser started as a kind of Barbie-and-Ken software, but slowly became more and more complex, most of all with the extra's made by Zygote who, later on, became Daz3D. Their latest mesh, Victoria3 is made for the newest computers because of the complexity.
The mesh (human figure) can be changed (arms can be lifted, eyes closed etc...) by introducing "bones". Bones are a kind of guides that tell the software that if, for example the finger moves, the hand and the arm and the shoulder move with it. This asks lots of calculation and therefore recent processors. The movements of a real human body can never be rendered: what we see is a simplification. The weakest point is the shoulder girdle.
The shoulder-girdle is extremely complex: on the level of the skeleton, the arm is only attached to the breastbone. All the rest is held together with muscles and tendons. The collar bone is attached to the breast bone, and on the other side, on the shoulder itself, to the shoulder blade. To the shoulder blade, the upper arm bone is attached. Many, many muscles are attached to these bones, and to render these correctly, even the newest dual xeons with hyperthreading aren't sufficient. We are coming close to believable characters (think of Gollum in LOTR2), but it's still visible that it is digital. Yet, to render this they use render farms with 1000 processors and more calculating twenty four hours a day.
Meanwhile, CuriousLabs made Poser5. Better meshes, but badly coded, and needing so strong a comp that the mac version will probably never come out. (because the Level3 cache cannot make up for the weakness of the processor here). Yet, for $149, it is worth its money, imo.
Good news is that Daz3D is making their own app, and the beta version will be for free. This will probably be the end of Curious Labs and Poser.
So we, Photoshoppers, are lucky: we can paint, draw, and select untill the shoulder is correct. For those with limited knowledghe of artistic anatomy: do a search with google on the subject, and observe, observe, observe. Try to see without knowing what you see. Concentrate, pay attention. Knowledge always places itself between reality and the image we create of it.