Which camera is good for professional photography?

I want to buiy the Nikon D3100, but i want to know which one is better, or the D3000, or the D5000
please answer and ill give the first one with the right one 10 points!

To be honest i don't think anyone can give you the 'right' answer they can only give their opinion and that will differ from one person to the other.

At the end of the day i'd suggest going into a camera store and asking to look at both. Get a feel for them and see which one you prefer that way.

You could get a hundred people tell you it's one camera but if you buy it and don't like it then you're losing out.

Before you decide on what camera you want to invest in you are going to have to figure out what area of professional photography you are going to enter. There are digital and film cameras. Each has an advantage over the other for specific applications. If you are going to enter the sports field a small format (35mm clone) digital may be best for you, especially if it is going to be published in newspapers or magazines. (In newspapers particularly and to a degree in magazines a very high quality image is not needed because of the size and relatively low resolution on the printed page. For studio work, especially where you may be using a tripod or studio stand, a larger format (digital or film) may be appropriate. In the commercial studio film cameras using film up to 8x10 inch in size are still not uncommon. Higher resolution digital cameras (allowing much larger prints or images) are available but are not inexpensive.

My intention is not to discourage you from entering professional photography but to make you aware that the equipment (and the photographer) must relate to the job at hand. It's a good field, interesting and a lot of work, Oddly enough I met my wife while photographing a state fair!

Professionals can use any camera

You are saying "professional photography" and asking about entry level DSLR cameras.

It is the photographer who makes a great image, and can do so with any camera. However, when you enter the professional realm, there are more things to consider.

Image - If you are saying you are a professional, and trying to get clients to pay money for your services, having a camera that is better than theirs helps. An entry level DSLR does not usually do that.

Focus speed - An entry level camera does not have the same processing power as a professional camera, so focus speeds will be slower.

Shutter Rate - If you are shooting sports, your frame rate will be too slow for lots of situations. The D5000 is around 4 frames per second, the D3 around 10. 10 frames per second will get you more good shots.

Buffer size - The D5000 buffer will fill up faster than a D3, so your shooting time goes down.

Shutter life - The D5000 shutter is rated at 100k actuations, a D3 is rated for 250K.

Construction - A D5000 is mostly plastic, a D3 is mostly metal.

Lenses - A D5000 can only use AFS lenses with full function, a D3 can use any lenses, including manual focus, and function.

In some situations, using a D5000 would make sense.

If you're shooting portraits in a studio, then it would work. You're still losing some of the image boost of a better camera, but the sensor would produce quality prints. If you're planning on doing stock photography, they don't care as much about camera as the images, so again, it would be OK. If you plan on doing anything with high speed subjects, low lighting (weddings) or adverse conditions, the D5000 will probably not hold up as well.

Not saying you need a D3, and the D5000 is a good camera with a great sensor. But, if you are planning on marketing yourself to clients, you might want to think about a better camera. A D300s is a much better camera, has same sensor, is more solid, will shoot at 8 FPS and costs 1500.00. I still wouldn't consider using a D300s as a primary camera for weddings, the D700 or D3s are wedding cameras. A friend of mine shoots weddings. She was constantly losing jobs to other photographers. She stepped up, bought the 2.8 "package", 14-24, 24-70 and 70-200, at a cost of around 6, 500.00. Now she gets the wedding jobs.

All are good for professional photography. The camera is just the tool, the quality of the pictures it produces depends on the photographer and not the camera. No one asks an artist what brand of oil-based paints or canvases he uses; why should cameras be any different?

If it was up to me, I'd go for the D3100 since it's the newest. It has a newer sensor which should mean better image quality, and a better video mode as well. Unless you really want the flippy screen of the D5000, go for the D3100 instead.

However, if saving your money and going for the D3000 instead means you have money left for real quality lenses, the end result will be better than either the D3100 or D5000.