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Thread: If eyes were lenses?

  1. #21

    Default Re: If eyes were lenses?

    Quote Originally Posted by Timber Wolf
    Hey. I did abit of research about the eye for my science project, so this might help.
    This is cool stuff.
    Now...if the camera makers would just learn from nature...the Maker Himself...

    The Differential System stuff is way advance for me to understand, but if only our DSLR sensors could make use of the principle to create a DR as wide as the human eye!
    Last edited by Ah Pao; 27th April 2006 at 10:01 PM.

  2. #22

    Default Re: If eyes were lenses?

    Quote Originally Posted by unseen
    Wah... this is best. LOL i learn new thing today..
    Wootz I've a IS system in me! Is there a disease where someone loses his VOR???
    Well. Research is fun. Was having attachment at DSO lah, so have to read up until i'm up to standard =P

    Unseen:
    Yes, it can happen thru disease or physical injury. The system is quite complex, cut one wire here and there and there it goes. You can damage your ear-balancing system, have a motor accident or stroke and sever one of the nerves (which is what happened to that guy in the case study), destroy the part of your brain which is responsible for VOR, and say goodbye to VOR.

    QX

    Ah Pao: I'll see if I can make a diagram. =)

  3. #23

    Default Re: If eyes were lenses?

    Quote Originally Posted by Ah Pao
    This is cool stuff.
    Now...if the camera makers would just learn from nature...the Maker Himself...

    The Differential System stuff is way advance for me to understand, but if only our DSLR sensors could make use of the principle to create a DR as wide as the human eye!
    Might be difficult becase it would not work for long exppsures then again you wont need it becuase it would be super sensitive and have natural HDR...
    Furry Photos - Photography for the Modern Pet

  4. #24

    Default Re: If eyes were lenses?



    This is the principle. It's not really refined, I know, but research is still ongoing, so I can't really say too much about how it works at this point cos i don't know

    QX

  5. #25

    Default Re: If eyes were lenses?

    if eyes are lenses....machiam camera...then i still buy camera for wat hahah...

  6. #26
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    Default Re: If eyes were lenses?

    Quote Originally Posted by Timber Wolf
    Hey. I did abit of research about the eye for my science project, so this might help.
    Optics
    According to the Standardised Human Eye website which is extremely cheem and has details on just about everything mechanical about the eye, the iris opening of the eye is 7.0mm+ in bright daylight and 2.0mm- in dark conditions. Given that the focal length is about 17mm for most people, eye aperture is about 7/17 = ~f/2.5 in dark conditions, and f/8.5 in bright conditions.
    Wait a minute. Why would the "aperture" open wider in bright daylight, and narrow down in low light conditions? Is something amiss here?

  7. #27

    Default Re: If eyes were lenses?

    woah. this is veri interesting.......
    since u say tt if any image tt stays at the same place in the retina wld disappear, does tt mean tt our eyes mus be constantly moving or vibrating so that there wld always be contrast differences?

  8. #28

    Default Re: If eyes were lenses?

    Quote Originally Posted by lsisaxon
    That's a good one. Auto ISO, Auto limited WB, Auto focus (age<50), limited fixed focus (age>50), high dynamic range, auto tracking..
    Do not forget the auto aperture, auto lens cap on/off, auto dust cleaner and high quality seal.

  9. #29

    Default Re: If eyes were lenses?

    Quote Originally Posted by Del_CtrlnoAlt
    Paiseh, i cannot agree...

    my WB constantly off... and permanently off also... mistake pink for blue, mistake green for red...
    You got red-green defect?

  10. #30

    Default Re: If eyes were lenses?

    Quote Originally Posted by sehsuan
    Wait a minute. Why would the "aperture" open wider in bright daylight, and narrow down in low light conditions? Is something amiss here?
    I think he got it reversed there.. The aperture f-number is correct though.. And that's quite an amount of information though it is greatly simplified.
    Last edited by lsisaxon; 28th April 2006 at 01:33 AM.

  11. #31

    Default Re: If eyes were lenses?

    lol maybe sniper got a wider f and a longer focal length....

  12. #32

    Default Re: If eyes were lenses?

    Quote Originally Posted by duhduh83
    lol maybe sniper got a wider f and a longer focal length....
    No.. Sniper got more steady hands/arms..

  13. #33

    Default Re: If eyes were lenses?

    Actually using rifles and cameras are almost the same, the same fundamentals. Maybi tts y u call both shooting.

  14. #34

    Default Re: If eyes were lenses?

    the WB of my left and right eyes are not similar! help!

  15. #35

    Default Re: If eyes were lenses?

    Hello. =)
    Sehsuan: My bad. Yeah, it's reversed.

    raptor84: I'm not really sure about long exposures for the eye, but I find that at night, when your eyes are fully dark adapted, if you swing a light stick you can see the path of the lightstick for quite some time. Some experiments state that the eye has an integration time of 15 seconds, but I'm not sure how it's possible (i.e. the brain uses 15 seconds worth of inputs b4 comparing differences).

    duhduh83: I think it's more likely that steadier arms help. Technique too. But there was one study of a woman who could recognise faces even half a mile away. Apparently something happened in her eye which gave it a focal length about 20x normal. Her field of view was limited, but she compensated for it by doing many rapid saccades.

    mercurial_streak: Yes. There are eye movements called Fixational Eye movements, where microsaccades occur so that the image is constantly shifting and your eye photoreceptors are constantly stimulated by changing light levels. You don't notice it partly because the tremors are small and frequent and because your brain actually compensates for it. Something like Sony's 60 fps and software frame-comparison and blur reduction stuff.

    michhy: So does mine. My left eye is slightly warmer (yellower) in colour and my right eye is colder (blue-er) Nothing to worry about though. I hope =X

    You can read about fading images here



    Cheers!
    QX
    Last edited by Timber Wolf; 28th April 2006 at 03:18 PM.

  16. #36

    Default Re: If eyes were lenses?

    one of the most interesting threads I've read so far...
    then how bout the stereoscopic vision? maybe Kodak can do another 2 lens camera...

  17. #37

    Default Re: If eyes were lenses?

    Hmm. Stereoscopic vision? Well, to start with, you need two identical sensor/lens assemblies. For 3-D vision at distances less than infinity, the sensors have to turn inward such that the centres of the sensors point toward the same subject. Having both sensors straight on would be unacceptable as they would be looking at different things. The human visual system deals with that using Vergence, where blur data and focusing distance are used to compute the amount of inward-turning the eyes have to perform.

    Blur data is derived from the image data and is processed in the pretectum. Unlike SLRs which use phase-detection focusing systems, our eyes focus by contrast-detection and image recognition/prediction. In other words, it's somewhat like conventional digicams but -much faster- because we already know how the object (i.e. someone running towards you) will behave and most of the focusing is predictive in nature.

    Focusing distance is measured by the proprioceptors (strain receptors) found in the ciliary muscle, which pulls on the lens to focus it. Basically, the greater the strain, the closer the focusing distance. One may argue that since the lens is fatter when focusing close-up, less work has to be done by the muscle and hence less strain because the lens is elastic and naturally fat, but if you look at the diagram of the eyes, you'll see that our eyes are optimised for long-distance viewing because the lens is focused at infinity (assuming no shortsightedness) when the muscles are fully relaxed.

    The degree of strain, coupled with blur data influences the amount of Vergence present in the eye.

    For stereoscopic vision, that was out of the scope of my research, but you can have a look here for more info. =)

    Cheers
    QX
    Last edited by Timber Wolf; 29th April 2006 at 12:27 AM.

  18. #38
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    Default Re: If eyes were lenses?

    Quote Originally Posted by Timber Wolf
    Blur data is derived from the image data and is processed in the pretectum. Unlike SLRs which use phase-detection focusing systems, our eyes focus by contrast-detection and image recognition/prediction. In other words, it's somewhat like conventional digicams but -much faster- because we already know how the object (i.e. someone running towards you) will behave and most of the focusing is predictive in nature.
    Fascinating stuff. I know its not entirely analogous, but out of curiosity, if you had to choose would you say the image capture (retina) and processing (brain) were more like digital imaging or film?

  19. #39

    Default Re: If eyes were lenses?

    Quote Originally Posted by dkw
    Fascinating stuff. I know its not entirely analogous, but out of curiosity, if you had to choose would you say the image capture (retina) and processing (brain) were more like digital imaging or film?
    i tink it is more like video?

  20. #40

    Default Re: If eyes were lenses?

    And your DNA would be your permanent watermark.

    what's scary is that your brain has a few 'folders' for memory, feelings, motor function (cortex, hippothalamus, amygdala etc.) and they all function based on electrical impulse. (1's 0's)

    Once the scientists map that down or are able to translate a signal... accessing your photographic memory like a hard-drive would be a raping for your brain =)

    And women take over the world and use men as reproductive 'milking machines' & batteries for the 'The Matrix' =P Not the f**ckin robots...
    Last edited by Rev; 5th May 2006 at 01:04 AM.

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