The Alpha 550 is the first Sony DSLR I have handled. It offers a few advantages over Canon’s and Nikon’s offerings in the same price category and for those who don’t mind the more limited choice of lenses, or those who happen to have a collection of Minolta DSLR lenses, it could be an excellent choice. It should be noted that the A550 does not have a video mode, while equivalent Nikon or Canon models offer at least 720p.
The camera body has a very comfortable grip (even for my outsized hands) and the many dedicated control buttons are also thoughtfully laid out. The A550 has an excellent 920K dots LCD screen. The screen can also flip up or down 90 degrees for the parade and dachshund shots. I usually prefer using the optical viewfinder for the extra stability one gets from pressing the camera close to one’s face. The viewfinder is adequate, but like most digital SLRs I have used, it provides a smaller screen than your average film SLR and is therefore harder to use for manual focus. >> There is also a separate LCD mode for the viewfinder       <<My single gripe with the layout of the controls is the dial in front of the shutter. I kept turning the camera off when using the dial to adjust the apperture.
User review of the Sony A550 DSLR
The A550 has the usual overwhelming choice of settings and “scene modes”. I prefer to use either aperture priority, shutter priority or manual and always shoot in RAW on a DSLR. With P&S cameras I use RAW+JPG and aperture priority most of the time. The camera has two interesting settings for dealing with the limited dynamic range of current CCD and CMOS sensors. One is the “Dynamic Range Optimizer” and the other “Auto HDR” (high dynamic range). DRO is similar to Nikon’s “active D-lighting” and Olympus’ “Adaptive Gradation”. All three brands use the “iridix” engine from Apical Imaging. Canon has two settings: “Auto lighting optimizer” and “Highlight tone priority”, which do not seem to be based on Iridix. The goal is to adaptively compress the dynamic range the way the human eye sees a high dynamic range image. Iridix claims this gives superior results from adjusting a curve or using the shadow/highlights tool in Photoshop. I am including three test images, comparing a regular shot processed with Photoshop shadow/highlights, one with DRO as post process on the RAW file and one with DRO in camera dynamic range compression. PS Shadow/highlight gave considerable more control and I was also able to “push” the parameters much further than when using DRO on a RAW image in post. Be that as it may, for the casual user who does not want to spend that much time massaging images, in camera DRO is a wonderful shortcut. The A550 has a tendency to produce very saturated jpg images, especially the reds. This seemed even more pronounces when using DRO in camera.
Auto HDR works by shooting two different exposures in rapid succession. The processor first aligns the two images (provided there was not too much movement of the camera) and then blends the best exposed pixels from each image. This is a very intriguing idea and the A550′s “best in class” rapid fire minimizes the chance of camera movement between the two shots. The problem is that Sony does not seem to process the two images very aggressively. When one uses Enfuse for dynamic compression, it is always a good idea to first optimize brightness and contrast of each image in the exposure bracketed series and then feed the series to enfuse. This way one can almost always capture the full dynamic range with 2 or 3 images. But I get the impression that auto HDR just uses the two exposures as they are. Very often autoHDR’s max 3 e.v is just not enough to capture a reasonable dynamic range. The A550 gives a maximum of 0.7 ev for exposure bracketing and is therefore also not usable for regular HDR, where one brackets 3 or more exposures, 2 stops apart.
Personally I prefer a bit of extra shadow noise to blown out highlights, so on most cameras I under expose about 1/3 stop. The A550 also has a tendency to overexpose, but I was able to recover more of the highlights in the RAW images.
The A550 stabilizes internally instead of letting the lens do the work. This is good news for people who will use this camera with older Minolta lenses.
With the A550′s fast frame rate of 7 frames per second, very fast autofocus and excellent live view screen, this camera would be a good choice for action photography.
Carel Struyckensphericalpanoramas.commetaloci.com