My main question is: What are the advantages of CS4, what can you do with it which isn't possible in Elements?

What I would miss in Elements (if it's still the same in 8, I used 6 before switching to CS): Working in layers on a 16-bit image. Elements didn't allow that, you could either work in 16-bit colors flat files or in 8-bit colors layers.

You might also want to look into Lightroom. Price is between Elements and CS. It's more photographer oriented than CS, you can do a lot of things in there easily. But the interface is pretty different, so it's hard to get tips from others. I use it as a library tool and for the RAW conversion before switching to CS for the fine-tuning of the image.

Then again, if you don't earn a lot money with photography yet, you might want to keep your investments low at the beginning. It's not as easy to get the money back as a newbie than it might have been three or four years ago.

The main differences would be CMYK and Lab color modes, and the Pen Tool.

If you need to ask "what is Lab color?" then you don't need it. The Pen tool essential for me to do quick isolations.

I have old elements 5 (which I have not used in a long time), and Layer Masking was either poor or non existent. Maybe it's improved with version 8. Layer masking is another thing that's essential for me, I found a clunky work around in the old Elements, so it did work to an extent, you just had to find the trick to doing it. I really only bought the old elements to get the video bundle.

PS elements is a very capable tool, and as mentioned, if you are a beginner it's the best place to start. You may also want to check out GIMP which is free, if only just to get to know your way around a photo editor.

http://www.gimp.org/

Check also PSP, the X3 version was just released (I knew the cheap price a few weeks ago had a reason!).  I can't tell about PSE8, but when I used PSE6, I found it very weak.  For US$100 you can get a much better software with almost all functions you find in PS.

Depends what you need and what you are willing to spend:
1. Photoshop Elements 8.0 - $80
2. Photoshop Lightroom 2.0 - $220
3. Photoshop CS4 - $680

If you are total newbie I would spend time and money on learning photography and get the cheapest software.

Thank you all!
I think I 'll try GIMP and PSP first and then decide. CS is so expensive; I've only earned about 2 dollar a week so far on microstock, so it will take about 6 years to get the investment back LOL.

Sharpshot,

It's been a while since I tested PS (I still have it in my mother's notebook, but I don't use it at all), but I remember it lacked a couple of things I use a lot, such curves or levels or layers - I can't remember which.

I won't be upgrading to X3 soon, maybe by the end of the year, when they often have sales prices.  X2 is very different from PSP7, but I got used to it quickly and I often discover new useful things.

I've started using Elements 8 and I guess the big missing thing, compared to PS, is layer masks. But PS costs $600 more.  Forget it. Not going to happen.

My opinion, since you haven't used CS$ and only used Elements for a short time, you don't really know what you need or what the limits are. And since one is about $700 and the other is less than $100, it would make more sense to stick with Elements until you learn how to use it and begin to hit its limits.

I used Elements for a few years before going to CS. I wouldn't go back now, but you don't know what you don't have yet.

Also, a lot of what you learn in E will tranlsate to CS, making the learning curve easier now and later.

To answer your question, there is a lot you can do in CS you can't do in E, otherwise it wouldn't cost 700% more, but do you need it and do you need it now? I don't think you have enough informaiton to answer those questions.

I started with PSE5 and now have PSE8. I think it's great and haven't come accross anything PSE8 won't do for stock. I've used full Photoshop plenty of times at employers but for just photo editing I don't see the justification for the extra money.

I also don't get the hype around Lightroom. Tried the trial. Looks like a very pretty photo organizer with some touchup tools. No layers or other advanced stuff.