What is the best SLR digital camera for a budding photographer starting her own portrait business?

I am on a budget right now and don't really want to spend more than $800. And I still have an old Pentax ZX-50 film camera in top condition. Would a photo shop trade that in?

You need to understand:
1) Posing
2) Light (natural light, augmented (light box) and studio lighting)
3) Depth of Field based on the setting.

If you understand these three thing you will be able to still use your existing gear and still take great pics. Since you want to do this as a business its a good idea to develop your skills by assisting someone else in a studio or in their business. You will learn a million times more by assisting and observing someone else.

I can suggest getting a Canon 40D with a 135mm f/2L, 85mm f/1.8 and a 50mm f/1.4 with a couple of light boxes and alienbees but that will not give you the experience you need in posing and lighting. And these two make a world of a difference and have nothing to do with your gear.

Canon has a great digital SLR in that range. I own one, EXCELLENT camera, you can get packages on ebay including the macro lenses for phenominal pricing. I paid $1000 for the camera & 3 macro lenses!!!! Good Luck!! =)

If you own pentax lenses already, take a look at the pentax k10d or k100 DSLR's. That way, you can use the lenses you already have instead of buying new ones. That'll definitely save you some money.

I agree with the honor's answer. It's always smart to buy a new camera that u already have lenses for. But if you don't want to go in that direction canon makes some very cameras and so does nikon in that price range.

Check out the Nikon D40 or D40x
and also the Canon eos digital rebel XTi

www.dpreview.com is a very good unbiased site that compares cameras for you.

You'd get maybe $30 for the used film SLR. Don't bother.

Instead, since you've got some experience with Pentax, consider the Pentax K100D Super or even the Pentax K10D. They will even accept your ZX-50 camera lens, so you can keep the film camera for those times you want to shoot film.

You'll still be under your $800 limit even with a lens. However, you might not have a lot of money left for accessories.

Alternatives: Canon Digital Rebel XT or Nikon D40. If you went for the Nikon D40 with an 18-55mm lens, you would still have enough money to get an SB-800 professional flash and still be under $800.

Don't forget you'll need other things--a memory card, a printer, cables, a computer and software--to round out the whole photography package.

Digital sucks at portraits.

It can't render the subtle contrasts in human faces and ends up making them look like video game characters. Even portraits from $10,000 digicams look lousy.

Get yourself a Hasselblad 500 C/M. They're going for about $1000 used, with the 80mm lens.

The Hassy will blow away your digicam-using competition and make you look like Richard Avedon (assuming you have some talent!).

For previews, you can use just about any cheapie digital compact hooked up to your computer.

Go and Google Image "Hasselblad portrait " and look at the shots. They speak for themselves.

HTH.