better photo editing software, CS4 or Aperture 3?

First of all, CS4 is only a version number, not a product. There is Dreamweaver CS4 that only edits web sites, and Premiere CS4 that only edits videos. It sounds like you are talking about Photoshop CS4, which only edits photos.

You are actually asking about Photoshop vs Aperture. They can't be compared so easily because they are for different purposes. Photoshop is a conventional photo editor with pixel brushes and total control, and best for individual document editing. Aperture is a pro-level bulk photo processor; it is much faster than Photoshop for organizing and developing large photo shoots especially those shot in raw format. However, Aperture's editing abilities are not as deep as Photoshop; Aperture has no layer or channel editing, no CMYK, no alternate color spaces or indexed color, no way to combine multiple images or create layouts like posters. Photoshop has all that. Aperture is more like a super-iPhoto for professionals.

Photoshop is not the direct competitor to Aperture, so many pros use them together since they have different strengths. The direct competitor to Aperture is actually Adobe Lightroom. Apple does not have any product that can compete directly with Photoshop.

One route you can take is buying Aperture and combining it with the more basic Photoshop Elements (under $100). This is an economical way of being able to use and combine both apps for their strengths.

>My sister is a graphic artist and she has the professional version of all the Adobe software (Adobe Creative Suite 4, Design Premium) which she gave to me when she upgraded to CS5.

The bad news here is that you won't be able to use your sister's old copy of CS4. The software requires product activation and your sister's upgrade to CS5 has cancelled any possibility of using her old copy of CS4. Adobe specifically prohibits that and once a serial number is used to upgrade to a new version, it can no longer be used.

FyrBndr wrote:

What I have noticed is the Ap 3 appears pretty RAM intensive and seems to "bog down" my MBP (2.66 core2duo, 8GB RAM, 360GBHD). This is another reason I was considering using something else, as well as purchasing a new MBP (see my initial post).

Photoshop can get slow too, if you pile on the layers and other features. There are tech notes you can read about how to manage RAM with Photoshop, because if you ask it to do certain things, like panoramas and HDR, it could need as much horsepower as Aperture. It's just the nature of image editing, especially if done with many-megapixel images.

FyrBndr wrote:

I didn't realize you could use both interchangeably.

Not actually interchangeably, but differently according to their strengths. The medical analogy (pardon me if this is lame) might be Aperture is a fantastic general practitioner that can expertly process a bunch of patients in an hour, while Photoshop is the surgeon who gets called in to do amazing things no one else in the hospital can, but needs a 6-hour surgery to do it.

danegeld wrote:

>My sister is a graphic artist and she has the professional version of all the Adobe software (Adobe Creative Suite 4, Design Premium) which she gave to me when she upgraded to CS5.

The bad news here is that you won't be able to use your sister's old copy of CS4. The software requires product activation and your sister's upgrade to CS5 has cancelled any possibility of using her old copy of CS4. Adobe specifically prohibits that and once a serial number is used to upgrade to a new version, it can no longer be used.

More specifically, the license is for the product, not for the version. The entire upgrade chain belongs to the one license. CS gets 2 activations (which are supposed to be used non-concurrently by a single user, like desktop and laptop or home and work). It is possible for both people to activate one copy within the two activation limit although this is technically a violation of the single-user license.

Legally, only you or your sister can use that suite. If your sister chose to transfer the product license to you, there is some paperwork to fill out and then the license and all future upgrade rights would become all yours and not hers, instead of how it is right now where it's all hers and not yours.