Sony SLT-A57K Questions & Answers

Level 7

Semi-transparent mirror allows light through to the sensor at all time

Level 1

It literally means that the mirror used in the SLR doesn't flip up the way it does in traditional SLRs, it's partially see through - so that light passes though the mirror instead of the mirror needing to move out of the way. Some people believe this makes it closer to a mirrorless interchangeable lens camera, and some people say it is not, because it still uses a phase detection auto focus sensor.

So what that means in laymans terms, is that your Translucent Mirror camera will be able to be focused all the time, real time, whether you are looking through the eyepiece or the LCD, they are both the same live image. Other cameras use a different method, and there is a slight delay when you use use the LCD viewfinder for shooting, or when using continuous shooting mode. You will also notice that the translucent mirror cameras are faster in continuous shooting mode, this is because they don't have to move the mirror, or keep it moved, out of the way. There is no camera shake from the mirror movement, which isn't noticable in most shots anyway, but sometimes there are those really precise macro or high zoom shots that every bit of extra stillness you can get counts. With the Translucent mirror technology, you can view all the settings, even the white balance and exposure, on the electronic viewfinder, and adjust them before you take the photo. You don't have to flip back and forth to the eyepiece to see these.

But How??? The Translucent mirror splits the light coming in, basically. Where a regular mirror would direct the light toward the sensor, or flip up and NOT direct it toward the sensor, this mirror allows the light to always hit the main sensor, AND always hit the seperate (phase-detection) auto focus sensor. So you get Hi-res auto focus all the time through the viewfinder, whether you are taking still shots or video. Since the translucent mirror lets light hit the optical viewfinder WHILE you are shooting video, you can get real time video image previews through the viewfinder - there's no mirror blocking it.

So why...? Well, I didn't buy my first Sony SLR, I won it in a training, and I got a good deal on a long lens. And then I had all these Sony compatable lenses! So my brand was chosen. But then when this came out with TEN FRAMES PER SECOND...well, I'm a nature photographer, and anything that will help me capture a bird in flight is high on my list.