YEKCIM said:
Or you could go for the S2-IS and save a little money. It is the 5MP precursor of the S3-IS and sells for around $320 from at least one reputable online dealer. It has the same 12X zoom and image stabilization as the S3.
~YEKCIM
Buying a recently discontinued model is a smat way of saving a little money. These new models come out every 18 months or so and - although they have improvements and slightly greater power - they are probably not dramaticlly better - and often the price is significantly less for the older model. 5MP is plenty - and here's a link to the S2 IS review - plus some selected comments comparing the S3 to the old S2....
"....We praised the S2 IS for the huge performance improvements made over the original S1 IS; we weren't expecting any great leaps forward with the S3 IS, and we didn't get them. ...",
"......The S3 IS is undoubtedly an improvement on its predecessor at higher ISO settings, both in the amount of measurable noise and in the visual impact of that noise on the resultant images. At lower ISO settings the differences are minimal, and it's worth mentioning again that the S3 IS has ISO ratings that are much more accurate than the S2 IS (which understates its ISO ratings; it's a lot more sensitive at ISO 400 than the new camera). ....",
"....The S3 IS files are very similar indeed to those produced by its predecessor, just a little bit bigger. As our lab tests show there is a small amount of extra resolution, but it's barely noticeable in real world images (it's likely that the amount of detail is limited by the lens, not the sensor). That said, there was always much to like about the S2 files, certainly if you like your camera to produce smooth, clean punchy images using the default settings. The images in both cases are a tiny bit over processed for some purists, but there are extensive controls in-camera for image parameters and color effects, so you can customize the output to some extent in the absence of a RAW option. Color, is typical Canon, with strong crowd-pleasing reds and blues, though in this case the reds are a little cooler, and more accurate for it. There doesn't seem to be much difference in the sensitivity between the S2's ISO 50 and the S3's ISO 80 - we've noted before that Canon now seems to be using more accurate descriptions of its ISO ratings (in other words the ISO 50 on the S2 is a bit understated). Either way, at the low end of the ISO scale there is little visible noise. Finally there is a slight fall-off in sharpness at the corners, but it's nothing too serious. ..."
Regarding studio scene comparisons at ISO 400
'....Anyone hoping for a 'great leap forward' in noise is going to be slightly disappointed; not because the S3 isn't any better (it has much finer grained luminance noise and slightly less obvious color blotches), but because the S3's ISO 400 is measurably less sensitive (around half a stop) than the S2, so what you gain on the one hand, you lose on the other. That said, the new camera's ISO 400 results (in good light like this) are surprisingly usable, especially if you don't intend to print them too big. Canon's fairly light-handed approach to noise reduction means that more detail is retained than we see in some competitor models. What is noticeable comparing the S3 results with the S2 results is that the new sensor appears to require less aggressive noise reduction and therefore detail retention is better, but again this needs to be balanced with the lower sensitivity. ..."
http://www.dpreview.com/reviews/canons3is/page6.asp
So it looks like the S3 gains ISO 800 versus the S2 with ISO 400.. but the noise levels are so hugh with the ISO 800 setting I would assume they are of marginal use. However, at ISO 200 the S3 is cleaner then the older S2 - while about the same at ISO 100 and 400.
The conclusion of the review on the S3 had this to say about it...
Overall conclusion
Where the S2 IS offered a huge performance leap over its predecessor, the S3 IS is in reality a minor upgrade, and with good reason; there was a lot less that needed improvement. Aside from the newer sensor, the welcome addition of a direct ISO button, sports mode and marginally bigger screen, the biggest change is the paint job, which has produced a camera that looks a lot less toy-like than the S2 IS.There is a slight improvement in image quality; a bit more resolution and much nicer looking ISO 400 output (though as noted in the review, ISO 400 on the S3 is nowhere near as sensitive as ISO 400 on the S2), but to be honest I think you'd struggle to see any real difference in a normal sized print.
Comparisons with it predecessor aside, the S3 IS Image quality is very good - certainly on a par with most of its competitors - though the results are still a bit on the soft side, something the fairly high default sharpening doesn't really help. Again, experimenting with the in-camera parameters and a little sympathetic post-processing means that in the right hands it can produce images every bit as good as anything else in its class. The ISO 800 mode is probably too noisy for anything but 'emergency' use, and there are occasional exposure problems, but generally speaking the output is pleasing enough to satisfy the majority of the intended market.
But ultimately, like the models that came before it, the appeal of the S3 IS goes beyond simple pixel-peeping; it has a class-leading feature set, a very reliable image stabilization system (the benefits of which cannot be overstated) and superb handling. It's well-priced, incredibly versatile and - above all - highly enjoyable to use. Despite the long lens and speedy operation it's not the ideal 'sports' camera (the focus at the long end of the zoom isn't fast enough and does hunt a little), but for sheer shooting pleasure and versatility the PowerShot S3 IS still takes some beating.
And so to the rating. There was a part of me that felt slightly disappointed that the S3 IS was such a minor upgrade, and that the new high ISO mode added so little. But there are some subtle but important improvements, and the S2 IS was a worthy recipient of its Highly Recommended rating. There are cameras out there that offer slightly better image quality (certainly in terms of sharpness), and I'm pretty convinced that the Panasonic image stabilization system is slightly more effective, but taken as a whole there is nothing out there that offers the feature set, handling and sheer fun factor of the S3 IS, and so it still - just - keeps hold of our top rating.