In the age of digital cameras, this EOS 5D almost a fossil, then anno 2005 (actually only 7 years ago) was the EOS 20D and the EOS 1Ds Mark II (both still small with a 1.8 or 2.0 inch display ) currently on the market, so I also appreciate the 2.5 inch screen of the EOS 5D, better displays at that time there was not yet, it is still regarded as sufficient to call and the large optical full-seeker is also in the old 5D very good.
Back then the world was still in order before the megapixel Run began, everyone thinks the more pixels, the better and produce what is in demand, it is unthinkable today a EOS 5D Mark III rauszubringen with only 12.8 megapixels.
Everyone thinks a digital camera should have LifeView and movie function and have the largest possible display (I watch the excellent images of the 5D anyway home favorite on the large monitor, and with joy again and again), the EOS 5D Mark III comes now an expensive autofocus (which is certainly good) and a digital spirit level, etc. to it, but is also the image quality is better, I doubt it, no more than the use at higher ISO values is real progress.
Who goes to the Zeitgeist should stay away from this "old" EOS 5D is perhaps not really "in", but if you just want to make great pictures which had just laid this old EOS 5D his heart, especially as these currently used for about is going to have extremely robust, reliable and durable - 500,.
This EOS 5D does not have any self-cleaning sensor unit, but even that is not really tragic, because there is so little bellows (I recommend Giotto's Rocket for nearly 10, -), so I blow the dust from time to time by the sensor down, works beautifully.
The image files I transfer directly from a CF card reader on your PC, which often works better than directly from the camera.
But as a camera like the good old EOS 5D will not come back, it's a proven fact that the old EOS 5D over the slightest noise (ie at low ISO) of all previously made Canon EOS full-format cameras has (and it shows very well ), and even up to 3200 ISO not really worse than the EOS 5D Mark II, the even higher ISO settings, I have not really used on my EOS 5D Mark II, because the image quality is simply much worse.
I have the Canon EOS 5D and the EOS 5D Mark II used in the last 2 years together, the EOS 5D Mark II is a super full frame camera, but at the end I was more pleased with the pictures of the old EOS 5D, very clear and plastically.
It pays just yet from that the old EOS 5D between them has larger pixels and place on the very good full-frame sensor. On "Traumflieger" .de a great test of this wonderful old EOS 5D is posted online, there is also evidence that the old 5D because of the size of the individual pixels on the large full-frame sensor is very comfortable with high resolution, and the resolution about the 18 megapixels of the EOS 7D is tantamount to the smaller APS-C sensor, because the individual pixels of the EOS 7D are just only about half as large as that of the EOS 5D.
In the image quality, it also comes very well on a good lens on, I can recommend the kit lens EF 24-105mm f / 4L IS USM or the Tamron 24-70mm Sp f / 2.8 VC USD and as the Canon 70- 200mm f / 4 L USM, quiet even without stabilizer (the most telephoto lenses can be very good on the EOS 5D use). But even the cheaper Tamron SP 28-75mm f / 2.8 is really not good and fixed focal lengths, then makes this camera very good pictures easy, a few of which I have set in the example images.
So those who do not by the whole modern features such as LifeView and video (I have hardly used) and can impress more and more megapixels, but creates great pictures wants, I recommend this very first EOS 5D with 12.8 megapixels, super well as a second camera if appropriate lenses are available anyway.
Addendum on 02.03.2013: I am using the good old 5D since about half a year in addition to the new EOS 5D III, I take them every now and then very happy to hand and am amazed at the in some cases even better in comparison to the 5D III image quality, am still convinced of the image quality of the first EOS 5D.