Backlit Sensor released, what now?

Discussion in 'Digital Photography' started by wheelhot, Aug 6, 2009.

  1. wheelhot macrumors 68020

    Nov 23, 2007
    Okay with Sony recently release its Backlit Sensor PnS cameras, what will happen to the DSLR world now? It is certain that Sony DSLR will receive these backlit sensors, but what will happen to the FullFrame format? now that you can use low ISO in dark places? Maybe Olympus was right about the 4/3rds format after all. LOL

    And most important, what will happen to the ISO now since the backlit sensor will solve most of the low light problem, not to mention that we might not having to use a flash anymore during an event or something (unless needed to achieve certain effect) since the backlit sensor will fix everything up?

    A video to show what I mean

    Sony DSC-WX1 (yeah, it's a PnS!)

    So in the future the difference between PnS and DSLR will only be:
    Details (since bigger sensor will produce more details then smaller sensor anyway)
    Build (well not everyone prefer DSLR size and build)
    Speed (well might change since future PnS seem to be able to focus quickly, shoot 10fps?)

    Hmm, guess the biggest point of a DSLR which usually refer to low light image quality will soon diminish?
  2. toanavinai macrumors member

    Jul 10, 2008
    Slightly irrelevant, but that panoramic mode they demonstrate in the video is awesome. Do want.
  3. ksz macrumors 68000

    Oct 28, 2003
    San Jose, CA
    This looks like the future of sensor design. Seems obvious to place interconnect wiring and peripheral circuits behind the sensor, allowing nearly all of the front facade to be used for light gathering. The manufacturing (or fabrication) hurdles for doing this must have been significant if it has taken this long to overcome. As is typical in the world of high-tech, when someone overcomes a hurdle, others follow in quick succession.

    On a more cynical note, I hope this does not reignite the megapixel race. With more surface area available for light gathering, some manufacturers might be tempted to increase pixel density.

    Finally, unless I'm missing something, I don't understand why Sony is using the word "backlit" to describe this sensor. If the interconnects and peripheral decode/IO circuits are positioned behind the sensor, it only means that the photovoltaic effect to induce current is taking place on the back. The back is therefore "lit" only in the sense that electrical activity is occurring there, but there is no light being emitted from the back. Instead, light from the front is being channeled to the rear.

    LCDs are backlit because they have to emit light, but sensors are not because they have to absorb light.
  4. compuwar macrumors 601


    Oct 5, 2006
    Northern/Central VA
    Nothing will happen to the DSLR world, other than perhaps a scaling up of the technology if it works well in a larger format. Larger sensors still have more well depth per pixel and a larger surface area, so the scaling issue is yet to be seen- but an improvement in any size sensor that's a leap is likely to scale up and be more of a leap in an even larger sensor.

    The ability to shoot in low light doesn't fix bad lighting or white balance issues due to bad lighting. We also don't know the dynamic range- it could be that the boost has a low overall dynamic range just shifting the problem on the tonal scale.

    No, there's still depth of field and angle of view, but the phrase "details" encompasses a lot, including the ability to crop, the ability to print large and likely dynamic range.

    I've never purchased a DSLR for low light image quality- so I don't think this is true outside of the lowest end of the market. If it affects anything, it'll affect the low-end entry level DSLRs, but if it scales up, works well, and doesn't affect sensor longevity, then it simply becomes a patent/licensing issue.
  5. toxic macrumors 68000

    Nov 9, 2008
    I'll be skeptical of the "backlit" sensor until someone tests it relative to current sensors.

    it has no influence on the position of SLRs. the larger sensor will always be superior in photography, limited only by ease of use, portability, and, for some, the cost of the longest lenses. if it really boosts low-light sensitivity with little or no compromise somewhere else, it will simply be re-engineered for larger sensors.

    the new sensor still does not affect quality of light, which is often lacking in low-light scenarios, which means flashes and other lights will still be commonplace.

    moreover, the "biggest point of a DSLR" was never low-light capability.
  6. Phrasikleia macrumors 601


    Feb 24, 2008
    Over there------->
    You seem to have forgotten the most important reason for anyone to invest in a DSLR system: interchangeable lenses!
  7. Padaung macrumors 6502


    Jan 22, 2007
    Anyone for ISO 102400 :eek:

    I think technically this is an fantastic acheivement by Sony. Will be interesting to see the real world results from these new cameras. If it's a success I'm sure the technology will be very quickly scaled up for DSLRs.

    I agree with the other posts about why DSLRs/larger formats in general will live on - functionality, depth of field, interchangeable accessories etc.
  8. wheelhot thread starter macrumors 68020

    Nov 23, 2007
  9. ksz macrumors 68000

    Oct 28, 2003
    San Jose, CA
    Sony is actually referring to the new sensor technology as back illuminated, not backlit. You can read the press release here on DPReview, which includes a schematic of the old and new.

    Not only are the photodiodes located directly behind the color filters and micro-lenses, but they are flipped 180-degrees so that incident light falls on their back side, which is free of interconnect obstructions.

    Because photodiodes are still built into the wafer substrate, it's not clear from the schematic how the metal wiring is fabricated. Metal wiring is typically fabricated above the substrate through a series of deposition and etch operations. Perhaps fabrication of the photodiode and metal wiring is still taking place in the normal fashion, but the color filters and micro-lenses are being applied from the backside of the wafer. This could be done by grinding the wafer's back side before layering on the filters and micro-lenses, but this is just my guess. In any case, I can see why it has taken so long to achieve back illumination.
  10. anubis macrumors 6502a

    Feb 7, 2003
    The challenge is that the n-p interface between the substrate and what Sony is calling the "light receiving surface" is now a much greater distance to the readout, where the metal interconnects exist. This means the conduction path of each photocarrier is longer, so traditionally you suffer from generation-recombination of the holes and electrons. You have to make the substrate very thin to minimize the distance the photocarrier has to diffuse. That's basically the technical will be interesting to see how well Sony's technology scales to the larger SLR sensor sizes

Share This Page