The digital SLR market has been flooded with many, many entry level cameras in recent years, but there are currently only a few cameras on the market that cater to the "prosumer" crowd. As a wedding photographer, I fall into this prosumer category and have been in the market for a new camera for months. To make my final decision, I had to weigh the merits of the Canon 5D Mark II, Nikon D700, and the Sony Alpha 900 against each other.

Why only these cameras?
The Canon 5D Mark II, Nikon D700, and the Sony Alpha 900 are all considered to be in the same class. Each of these cameras feature full-frame digital sensors, which most closely mimic the sensors found in old film SLR cameras and give a better overall quality of photograph. Simply, these are the least expensive cameras that will give me the quality that I require in photographing weddings.

Cost
Canon 5D Mark II: $2,499 (Body only)
Nikon D700: $2,699 (Body only)
Sony Alpha 900: $2,699

As you can see all three cameras are similar in price so this did not play a major role in my decision. Keep in mind that you will need to purchase a lens with each camera, which will cost another couple hundred dollars.

I almost purchased Sony's Alpha 850 based purely on price alone, as it is the only full-frame DSLR camera with a list price under $2,000. Ultimately, I decided against it and you will soon see why.

Resolution
Canon 5D Mark II: 21.1 Megapixels
Nikon D700: 12.1 Megapixels
Sony Alpha 900: 24.6 Megapixels

Sony reigns supreme in this category with Canon a close second and Nikon a distant third. Resolution is extremely important because it determines how large I can print photos.

Keep in mind to double the resolution of a photograph, say from an 8 x 10 to a 16 x 20, you actually need to quadruple the megapixels. Think of a 16 x 20 print with four quadrants. Each of those quadrants is 8 x 10, and four of 8 x 10 quadrant exist on this one picture. Hence, to double your picture size, you must quadruple the megapixels.

So, ultimately resolution is important, but the smaller total megapixels of the Nikon is not a deal breaker. In reality, each of these cameras produces photos of impeccable quality. If an enlarged print was taken from each camera, it would take a trained eye to see the difference in quality between prints.

Performance in Low Light
As a wedding photographer, performance in low light is one of the most important factors in determining my camera purchase. Many tests have been done comparing each camera when used at high ISOs (what you generally adjust when there is little light present). Canon and Nikon emerged as the clear winners with the Sony performing well but not nearly as well as the other two.

In Summary
There are countless other factors that can be compared between these three cameras, but the ones listed above were what weighed most heavily on my mind.

Nikon D700Nikon D700
The feature that most sets the D700 apart from the other two cameras is its continuous shooting rate, which was not discussed above. The D700 can shoot up to 5.0 frames per second and can expand to 8.0 frames with a vertical grip. This feature is of little value to me as a portrait photographer since I do not need to be shooting that many frames per second to capture a shot with my bride's eyes open.

The Nikon is recommended as the perfect camera for photographing concerts. It gives you the speed that you need and performs extremely well in low light. Unfortunately, it does not quite have the resolution that I desire in a full-framed camera.

Sony Alpha A900 Sony Alpha 900
I previously owned a Sony Alpha camera and was extremely happy with my purchase. This brand loyalty almost drove me to purchase the Alpha 900, but I am glad that I did not. Ultimately, the Alpha 900's performance at high ISOs was the feature that drove me away. When photographing a wedding, I cannot always use a flash, and sometimes it is necessary to increase the ISO to compensate for low lighting. As the ISO is increased in any camera, photographs tend to become much grainier. When the Sony is used at high ISOs, it does not perform nearly as well as the Nikon and Canon counterparts.

The other major factor in pushing me away from the Alpha 900 was Sony's commitment to professional photographers. Both Nikon and Canon have cameras at an even higher class than the ones discussed in this article (Nikon has the D3S and Canon has the 1Ds Mark III). The Alpha 900 is the top of the line for Sony and no indication has been given that any new cameras will be produced to replace the 900. Since I certainly will someday purchase a new, better camera, this commitment was a great worry to me. I did not want to sink thousands of dollars into a camera and lenses only to be forced to purchase a different brand in the future.

Canon 5D Mark IICanon 5D Mark II

When taking its resolution and performance at high ISOs into account, I had no other choice than the Canon 5D Mark II. Sure the Mark II offers live view and can shoot gorgeous HD video, but these factors did not weigh into my decision.

In contrast to the Sony Alpha 900, the Canon is one hundred percent committed to their professional photographer market, and I know that I will some day purchase another more powerful Canon camera. Thus far, the camera has performed beautifully. There is no looking back now.

If you own or intend to purchase this Canon camera, be sure to read this article regarding 5D Mark II Accessories that you must own.