You’ve probably read plenty of articles touting the benefits of Sony’s translucent mirror technology (e.g. high fps, AF for video, quietness, etc…), but what about the cons? One of the main downsides to having a translucent mirror is that the light hitting the sensor passes through an additional layer (the translucent mirror), which reduces the amount of light and the image quality.
Ray over at TheSyberSite attempted to quantify how much the mirror affects the resulting image quality by removing the mirror on his A55 and comparing the resulting photos. He confirmed that about 1/2 stop of light is lost, and estimates that 5% of the detail in each shot is lost due to the mirror. Head on over to the article for some side-by-side comparisons.
Secrets of the Sony A55 (via sonyalpharumors)
TIME magazine has named the Sony Alpha A55 as one of the top 50 inventions of 2010. They write,
A.K.A. the camera that never blinks. Traditional digital SLR cameras take the nicest photographs around, but they’re hobbled by a decades-old technical limitation: when you snap a picture, the mirror that’s been redirecting the image to your eye and to a focusing sensor pops up momentarily as the image is captured. Until it goes back down, the camera can’t focus. Sony’s Alpha A55 ($849.99 with lens) fixes that with an ingenious translucent mirror that stays put. That means you can shoot up to 10 perfectly focused photos a second and record HD video that never goes blurry. Bonus advantage: with no need to allocate interior space for a moving mirror, the Alpha is noticeably smaller and lighter than its Sony SLR brethren.
10 perfectly focused photos per second? That’s a pretty interesting claim.
Check out the full list of 50 inventions here.