The Canon Digital Rebel series is arguably the most successful digital camera series of the digital age. The Single Lens Reflex (SLR) cameras in the Digital Rebel series appeal both to the professional and to the amateur as well as to the newcomers that are giving up their compact cameras and step up to the versatility of the SLR. This appeal is largely due to Canon’s ability to combine accessibility and simplicity with a good build quality without compromising on the main attribute that describes a camera: image quality.

Ever since the introduction of the Digital Rebel XSi (also known as 450D), Canon has pushed the Digital Rebel series closer to its mid-range series (denoted by two digits, such as 40D, 50D), using elements such as moving from the usage of Compact Flash (CF) cards towards Secure Digital (SD) cards, upgrading the sensor, enlarging the viewfinder and many others.

The latest member of the Digital Rebel family is the Digital Rebel T2i (also known as 550D or the Digital Kiss X4) and comes to further the dominion of Canon with many new improvements. Since the camera was only announced in February 2010, we will look around at what novelties Canon is offering.

The first is a much-expected improvement in the building of the body. All the previous models, including the current 450D and 500D, had bodies made of plastic parts attached to a stainless steel chassis. In the 550D, the stainless steel chassis remains, but the outer body is made from polycarbonate resins and fiberglass. This is a great move from Canon especially since its main competitor Nikon has been using magnesium alloys for quite a while now in its entry level products.

As any good upgrade dictates, one of the improvements is the sensor. The number of megapixels in itself is definitely not the most important quality of a camera (as any experienced photographer will tell you) but having 18 megapixels under your finger will definitely help in some situations. However, the jump to 18 megapixels is definitely not the most significant upgrade the sensor received. In addition, the improved DIGIC 4 (which is a step beyond 500D and a close relative to the one used on the professional series 7D) boasts gapless microlenses, which allow for increased density of both microlenses and photodiodes on the sensor as well as increasing the efficiency of each pixel.

The screen received a minor upgrade, by getting a 3:2 aspect ratio (although the resolution and size of 3 inches remain the same as on the 500D). This moved is aimed at pleasing movie makers (as both 500D and 550D are able to record HD video) for whom a wider aspect ratio makes much more sense).

A much more important improvement is the upgrade of the metering system to one based on a 63-zone dual-layer sensor. The new division (also present on the professional 7D) allows for much more accurate metering, while the two layers work to reduce the overall sensitivity to the red color spectrum which plagues the classic metering systems.

The last on our list of improvements are the labeling of the ISO value 6400 as a main ISO setting. On the 500D, this value was considered to be an “extended” value (meaning that the user would use it while running the risk of getting extremely noisy images). Apparently Canon gained enough confidence in the improved DIGIC 4 in order to allow us to use ISO 6400 as a normal setting. An “extended” value is still present though, namely ISO 12800.

In addition, exposure compensation moved up, allowing us to choose any value between -5 and +5 exposure values (EV). Before, Canon has been widely criticized for limiting exposure compensation to -2/+2. Since most Digital Rebels have the tendency to overexpose, many photographers choose -1 EV as the default exposure compensation value (instead of the normal 0, the neutral value), thus greatly limiting the ability to further underexpose for artistic effects.

As we can see, the new member of the Digital Rebel family looks promising and unlike the previous upgrade from 450D to 500D, this time there are many reasons to upgrade. The metering value, the new ISO setting and the exposure compensation may be the main incentives to sell your old Rebels and get the new one (once it is launched). As a fairly famous photographer used to say: having the best camera doesn’t make you a great photographer, but it sure helps.