So Who Believes that Full Frame Camera's Gather More Light Then APSC

Discussion in 'Beyond the Basics' started by donny1963, Jun 8, 2018.

  1. OldManJim

    OldManJim No longer a newbie, moving up!

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    Try this experiment. Get 2 buckets, one larger than the other. Place them side by side in a rain storm for a the same amount of time. Measure the amount of water in each.


     
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  2. Solarflare

    Solarflare No longer a newbie, moving up!

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    And then measure the water each of them got. The ones with the bigger diameter ... had collected more water.

    Now realize that the circuit after the bucket will add a random amount of water, which we call noise. Its the same random amount. The bucket that had more water total will have thus less noise, because the larger amount of water is less changed by percentage from the same amount of noise.

    For the same exposure the larger sensor will collect more light, simply because exposure is light per area and the larger sensor has more area.

    Likewise the pixels on the larger sensor are likely to be larger, thus we will see better data from the larger sensor. What needs to be understood is that every pixel, no matter which size, runs through the same amplifier which has the same level of noise added. So if a pixel holds more charge the relative amount of noise will be less.
     
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  3. dunfly

    dunfly No longer a newbie, moving up!

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    There are only two things that determine how much light is gathered by any camera, aperture and shutter speed. It doesn't matter the size of the "bucket" the light falls in, the amount of light is the same.
     
  4. Ysarex

    Ysarex Been spending a lot of time on here!

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    You're confusing exposure with the topic of the thread which was total light -- see link:

    So Who Believes that Full Frame Camera's Gather More Light Then APSC
     
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  5. Dave442

    Dave442 No longer a newbie, moving up!

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    After going back over this link about equivalence it is pointed out that the aperture diameter is intimately related to the total light that lands on the sensor. Then he shows that an ASPC camera can receive the same amount of light on the sensor as a FF camera by opening the aperture (in the example with 50mm lens on FF and 35mm on ASPC for same FOV as same distance). This then gives the same Total Light on the sensor as the FF camera, but by then dropping the ISO on the ASPC camera the two images end up having the same brightness when processed by the camera.
     
  6. Derrel

    Derrel Mr. Rain Cloud

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    Not to derail this thread, but I'm looking for an iPhone app that will help me calculate the value percentage of the of China's tea industry as a separate part of the Chinese mainland's annual Gross Domestic Product. Any leads on a good app for that?:048:

    As far as this "total light" concept...it's amazing how at times, something nonsensical gets posted on a popular web site, or on YouTube, and it generates huge buzz, and despite inaccuracy, or utter B.S. reasoning, there is created a huge wave of misunderstanding,and the error is repeated over and over and over, and in that way, nonsense becomes "accepted fact". The idea of total light somehow being something to crow about, and forgetting that exposure is about Intensity X Duration at a given aperture value....ahh...sheesh....nevermind.
     
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  7. n614cd

    n614cd TPF Noob!

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    I always thought it was about pixels.
    If you a 35mm with the 20 mega pixel crop sensor and compare it to a 50mm with a 20 mega pixel full frame. The images and resolutions will be identified.

    Or am I missing something?

    Tim

    Sent from my SM-J737T using Tapatalk
     
  8. greybeard

    greybeard Been spending a lot of time on here!

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    Yes and no. A 20 mp FF file and a 20mp APS-C file should be roughly the same size and contain the same amount of information. Because the APS-C is sampling a smaller image size the lens won't usually be able to resolve as many lines as the FX. If you look at DxO lens testing, you will notice that FX lenses can resolve 25 to 30 MP where as APS-C lenses rarely resolve more than 14mp and in most cases it is like 6-10. And, if you compare the resolution of the same FX lens on APS-C, it will usually show much lower lower resolution numbers. There are darn few lenses on APS-C that can take advantage of the 21-24MP sensors on even entry level dSLR's
     
    Last edited: Oct 13, 2018 at 10:22 PM
  9. n614cd

    n614cd TPF Noob!

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    Yes. If comparing like lenses. You will notice I compensated for lens in my example.

    Tim

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  10. JBPhotog

    JBPhotog TPF Noob!

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    A rather simplistic deduction that contradicts many lens designs. Do you actually know the image circle of a lens? Hint, it’s not the same for every focal length.
     
  11. Trever1t

    Trever1t Been spending a lot of time on here!

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    sounds to me like a classic case of sensor envy.
     
  12. greybeard

    greybeard Been spending a lot of time on here!

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    If you think about it, the lens is what gathers the light and projects it onto a piece of film or sensor. Film through the chemical process of development creates a analog negative of the image. The sensor through multi-millions of pixels and the microprocessors they are connected too, creates a digital description of the image.
     

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