PetaPixel

Sony’s Translucent Mirror May Reduce Detail in Photos by up to 5%

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)


 
  • http://twitter.com/PlasticWig Joshua K

    Would having 24 megapixels make up for it in any way? Is the mirror translucent all the time, or can they turn it on/off using some special technique kinda like electric polarized lenses?

  • http://twitter.com/PlasticWig Joshua K

    Would having 24 megapixels make up for it in any way? Is the mirror translucent all the time, or can they turn it on/off using some special technique kinda like electric polarized lenses?

  • Anonymous

    This shouldn’t come as a surprise to anyone. Not only does the mirror put a layer of material between the lens and the sensor, it’s material at an angle. How can there not be refraction as well as diffusion?

  • Anonymous

    The NEX 7 will be the winner. The future is mirrorless, not translucent.

  • Anonymous

    The NEX 7 will be the winner. The future is mirrorless, not translucent.

  • Anonymous

    The NEX 7 will be the winner. The future is mirrorless, not translucent.

  • Anonymous

    The NEX 7 will be the winner. The future is mirrorless, not translucent.

  • TN

    I think the future is mirrorless too.  Look at some of the initial JPEG comparisons from the NEX-5n http://www.eoshd.com/content/3784/nex-5n-demolishes-ep-3-at-high-isos-even-beats-5d-mk-ii-nikon-d7000

  • TN

    I think the future is mirrorless too.  Look at some of the initial JPEG comparisons from the NEX-5n http://www.eoshd.com/content/3784/nex-5n-demolishes-ep-3-at-high-isos-even-beats-5d-mk-ii-nikon-d7000

  • Dave

    Exactly. And the fact that the mirror is undoubtedly made from a flat piece of glass which is also a great way to introduce refraction into an image.

  • Dave

    Exactly. And the fact that the mirror is undoubtedly made from a flat piece of glass which is also a great way to introduce refraction into an image.

  • Dave

    OK, flat piece of plastic or whatever, even worse.

  • http://blog.wingtangwong.com/ Wing Wong

    No doubt there is a huge benefit to not having a piece of plastic in the light path. I wonder how many people will remove the mirror from their A77(s) when they get them?

  • http://blog.wingtangwong.com/ Wing Wong

    No doubt there is a huge benefit to not having a piece of plastic in the light path. I wonder how many people will remove the mirror from their A77(s) when they get them?

  • Cochese

    Probably not many. I don’t even think many people who would care are going to be even using the Sony camera in the first place.

  • Cochese

    Probably not many. I don’t even think many people who would care are going to be even using the Sony camera in the first place.

  • Patent Atorney

    The A77 has two very cool new features. First is Sony’s new translucent mirror tech. This uses a pellicle mirror instead of the usual silvered glass panel. It lets the light pass through to the sensor, yet allows some (in an SLR) to be reflected up to the viewfinder. That means you can shoot very fast because the mirror isn’t constantly slapping up and down like a stupid dog’s tongue on a hot day.

    But the A77 doesn’t have an optical viewfinder. In this case, the mirror is used to siphon off some light to the phase-detection AF system, which lets it focus as fast as an SLR, and yet still manage a live-view. And what a live view. This one comes courtesy of the 2.4 million-dot finder, also found in the NEX7.

    The lack of a mirror also speeds things up. The A77 can shoot its huge 24-MP images at an almost absurd 12 fps.

  • shamb

    Sony are simply going for a different set of tradeoffs to the CaNikons.

    That Sony are actually the only company innovating in the otherwise slow and staid DSLR market speaks volumes, and can only be good news for all camera users as the competition hots up.

  • Bruce

    Though this is interesting and is obviously expected, it’s not really relevant in the whole scheme of things as it’s comparing a camera to itself – crippled on one way or the other (without the mirror or without the improved IQ). All cameras are systems including lenses, shutters, sensors, processing engines, etc. and IQ is dependent on the combined capabilities of all components. In some cases a component require a trade-off while others may not be able to be used optimally in order to make the system work properly. We can clearly (no pun intended) see that the use of the translucent mirror requires a trade-off and Sony has determined that the benefit outweighs the deficit. If the camera delivers what’s expected of it, then this is a moot point.

  • Ivan Sanchez

    actually is not glass… its kind of plastic.