looking for a low cost photo editing app

i collect rifles and i'm building a light box to take photos in. essentially what i'm looking for is a low budget/free photo editing software for the mac that will allow some color adjustment and will allow me to white out the entire background or cut the object out of the pic and place on a white background. forgive my ignorance as i'm pretty new to macs and playing with my DSLR (a whole 5 months).

Gimp.

Take a look at Pixelmator. It's not Photoshop, but it's easy to use, feature rich and extremely fast.

I'm not a huge picture editor myself but I quite like Acorn. Not super cheap ($50) but it might do the job for you.

If you want free, you could try The Gimp like CrimsonRequiem suggested. You can download it here.

^ Thats a bit too limited I guess.

GIMP will get work done pretty well. If you want to spend, go Pixelmator.

I would also go with Pixelmator to do what you want to do. I don't know of any free Apps that will let you cutout and object like you want. I think you get a lot of editor for $59 in Pixelmator and you may want to use some of it's other options as you learn to use it. It has a bit of learning curve but I think a lot Less than Photoshop or even the free Gimp.

^ Even though I use Pixelmator, GIMP is as easy.

Gimp, free, fast and extremely well made. But eventually if you need a bit more an advanced program get photoshop (worth it). =)

I use gimp. It meets all my demands, and is easy to use.

I just downloaded seashore it was free, and so far pretty good, but I don't know too much about photoshopping so it may be a bit limited compared to other options.

Why not use Preview, it comes with Tiger and leopard - the latest has heaps of adjustments and even Tiger versions of Preview were under rated for handling pics

mmm, i couldn't think of a better software for you than Gimp. It's free and extremely well done for a free software. If you are not a profi and you learn how to use ti well, you will never need any other software.