The question is not anywhere near as simple as Ramón says.
First, you said you want to shoot raw. This is where you start. You first determine what software is available for a G5 that provides raw support for the camera you are thinking of buying. You could just look at the supported camera list for the versions of iPhoto and Aperture you can run, and say to yourself that is the list of cameras you can possibly buy. The reason is that raw is not generic, an application must support the specific raw format of a camera. If you buy a camera but no software on your computer can open its raw format, you cannot open its raw files on your computer, period. You will be forced to use JPEG only. (If you want to use JPEG you can use almost any camera on the market today.)
The reason that is important is the vast majority of raw-capable cameras today work with software that doesn't run on a G5.
There are tripod mounts on almost all, but not all, cameras sold today. You probably won't have a problem, but it doesn't hurt to check. One issue is that some cameras have the tripod hole in a place that makes it impossible to change the battery or card without removing the camera from the tripod. If that concerns you, check for it.
Yes, a 14 megapixel (I think that is what you meant by Mb) picture may strain a G5. You might want to aim for 8-10 megapixels. But you also want to make sure you've installed 6GB of RAM or more.
Since your G5 is a PPC Mac, the last version of Adobe Photoshop/Bridge that will run on it is CS4 and the last version of Adobe's Camera RAW software that supports CS4 (and will install on a PPC Mac) is v. 5.7. dSLR cameras introduced after that will have no Adobe RAW support on PPC Macs.
For example, current Nikon dSLR models that are supported in Adobe Camera RAW 5.7 are the D3x, D700 and D300s. Current Nikons dSLR models that are not supported (and likely never will be) in Camera RAW 5.7 and PPC Macs are the D7000, D5100, D3100 and the recently announced D4. My experience is limited to Nikon cameras, but I suspect newer cameras from other manufacturers will be in the same boat.
A list of cameras from all manufacturers that are compatible with Adobe Camera RAW 5.7 is available here:
If you do buy a newer camera whose RAW format is not supported on PPC Macs you can work around the problem by downloading Adobe's free DNG Converter and convert your newer camera's RAW files to Adobe's DNG (digital negative) format and work with them in Photoshop/Bridge CS4 from there.
Network 23 wrote:
That is utter nonsense. (Sorry.)
I challenge you to name a single digital camera that has been on the market for over four months that generates raw files that will not transparently open on my G5 setup.
2.5 GHz Power Mac (PPC) G5-Quad; 16GB RAM; mutant, flashed 550MHz nVidia GeForce 7800GTX 1,700MHz 512MB VRAM; ATTO ExpressPCI UL5D LP SCSI card; Mac OS X Tiger 10.4.11 and Leopard 10.5.8 boot drives; Spotblight, Dashboard and Time Machine permanently disabled; dual 22" CRT monitors; USB wireless 'n' available but connected to the Internet via wired Ethernet; FW flatbed scanner; 2 SCSI scanners (one tabloid-size transparency scanner and a film scanner); various internal & external HDs; FW Epson 2200 and Ethernet Samsung ML-2850ND printers; 2 X Back-UPS RS 1500 XS units. — Photoshop 11.0.2 ("CS4"), ACR 5.7, Adobe DNG Converter 6.4.
I work with a bunch of digital cameras, including some that generate massive 5440 x 7264 pixel (40 megapixel) raw files, e.g. the Pentax 645D., as well as with humongous scand from viewcamera negatives.
The only camera model among all that William Bothel lists that is not not supported in my current G5 setup would be the Nikon D4 which, as he says, has only been announced. That's why I qualified my challenge:
…to name a single digital camera that has been on the market for over four months that generates raw files that will not transparently open on my G5 setup.
I will concede that once it hits the shelves, the Nikon D4,—which will cost $6,000, body only (without a lens, warranty extra) at discount stores like B&H—then I'll have to install the soon to be released Photoshop CS6 on a Mac-Intel box.
The Adobe DNG Converter won't do you any good for the Nikon D4, as the last version that will run on a Power PC is DNG Converter 6.4.
Coming to think of it, I should have no trouble at all batch-converting the NEF files from the Nikon D4 on my inherited MacBook (discarded by my wife) running Snow Leopard or Lion to raw DNG files and copy tem to my current G5 setup, should I win the lottery and buy a D4.
My point is that, for somebody with requirements as modest as the OP has, his computer is not a limitation or a cause of concern when choosing his DSLR, which I strongly suspect will not be a Nikon D4.