Viewfinder (3.5)
The optical viewfinder on the PowerShot A520 is so puny and useless that it seems purely vestigial. It may resemble other optical viewfinders, but it will not be much help when trying to compose an image. It’s very small, it doesn’t accommodate glasses well, and it’s not accurate. Even though you could save battery power by shutting off the LCD and using the optical viewfinder, it’s more trouble than it’s worth.
LCD Screen (6.0)
The PowerShot A520 LCD display is 1.8 inches across the diagonal, with approximately 115,000 pixels. Both numbers should be bigger – this is, after all, essentially the only interface the user has for most shooting. In manual focus mode, not enough pixels are dedicated to the focus area, so even in telephoto, when focus should really snap in and out, it’s hard to tell when you’ve got it right. It’s also 
hard to evaluate pictures in playback mode – they’re small, making it difficult to judge sharpness. The color of the screen is also pretty substandard and will not give a very accurate replication of the captured shot.
Many similarly priced cameras now offer 2-inch LCD displays with at least 154,000-pixels of resolution, as most manufacturers are aware of its marketing pull and the extent to which most digital cameras users rely on it. However, as it is with computers, the screen on a camera is one of the most expensive parts to manufacturer and additional screen size and capabilities would likely boost the price of the A520 substantially.
Flash (6.5)
First, the positive – The PowerShot A520 provides five selectable flash settings: Auto with red-eye reduction, Auto, Flash on with red-eye reduction, Flash on, and Flash off. In addition, the A520 offers a separate manual control of the amount of light the flash puts out, allowing the user to balance the flash illumination with the existing light in the scene. It’s a nice feature that’s common and well-used on pro cameras.
Now, the negative - The flash on the PowerShot A520 is awfully close to the lens, which means it is likely to produce “red-eye,” the peculiar glow caused by reflections off the retinas of subjects with relatively dilated pupils. There are two ways to avoid red-eye: move the light source away from the lens, or get the subjects pupils to shrink before taking the picture. Of the two, separating the light and the lens works better. Many cameras have flashes that flip up, away from the lens for that reason. Unfortunately, those little flash arms are often delicate, which might explain why Canon went with the other red-eye reduction method on the A520.
The A520 flash goes off twice in red-eye reduction mode – once just to get the subject’s pupils to shrink, and then again a second later, to take the picture. The problem is many people find the double flash annoying and objectionable. More so, it means the photographer will have to hold the shutter release about a second before you want the picture taken, and that can be tough to time properly.
The A520’s flash is also set to the side of the lens, rather than directly above it. This arrangement causes ugly shadows to one side of the subject. When the flash is directly above the lens, the shadows will fall behind the subject, and will not be visible in the picture.
Zoom Lens (7.0)
The A520’s 4x optical zoom lens has a moderate range, spanning 35-140mm (35mm equivalency). This moves from a slight wide angle to a telephoto that’s long enough for portraits, but not long enough for most sports. Unfortunately, with the limited wide angle capabilities, users will have to back up significantly to get everybody sitting at the picnic table into the picture. An additional 3.6x digital zoom is also available when needed, but as always, it is certainly not recommended as image quality will wane exponentially.
Users who are comfortable with 35mm cameras would say the lens is comparable to a 35-140mm lens. At the wide angle end, it has an impressive maximum aperture of f/2.6, which means it can be used in relatively darker places than some other lenses. The maximum aperture slips to f/5.5 at the telephoto end of the range, and the low-light advantage disappears.
Photographers who are familiar with aperture settings on film cameras might note that those cameras have much smaller apertures than f/8.0, the A520’s minimum aperture. Many lenses for 35mm cameras have minimum apertures of f/22, and lenses for larger cameras may have minimum apertures as small as f/64. Lenses on compact digital cameras can't close down that small because the lenses start out so small. F/22 on the PowerShot's lens would be functionally a pinhole, and would produce images about as well as a pinhole.
