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Thread: Digital Camera Noise Explained

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    Default Digital Camera Noise Explained

    What is camera noise, and why should we know about it? This is part 2 from the last romp through the internet called "What is Depth of Field".

    Back in the days when everyone was shooting film, you could (and still can) buy different films that increased light sensitivity through chemical means. Such sensitive films had a higher ISO rating. For example, if you where going to take photos in low light conditions, you could buy for example an ISO 800 or 1000 film that would allow you to increase your shutter speeds, but at a cost of image quality (daylight film was often at ISO 100, and you could even buy slide films at ISO 50 if you wanted super quality). Now due to the process of the chemistry and manufacturing of these sensitive films, you would get an increase in grain.

    Read this interesting link about 35mm film speeds and film grain here.

    and this one that explains ISO.
    ISO explained

    Now, there was nothing wrong with grain, and many photographers would incorporate the film characteristics as an artistic extension of their vision. But for most people, film grain was something to avoid.

    Now lets roll to digital cameras. All digital cameras use a sensor (either CCD or CMOS) instead of traditional chemical film. A hold over from those film days however, is the ISO function of your digital camera. Simply put, you can make your mechanical sensor more sensitive to light. Wonderful for low light conditions. However, there is a cost very similar to film, and that is digital noise.

    Read this short link that explains digital noise.
    Noise explained
    and
    More about noise

    Now the main thing to remember is that the increase in noise is directly related to the image sensor size, the size of the pixel pitch or resolution, and the quality of the noise reduction softeware/filter built into the camera.

    Small compact cameras have very small image sensors. If these cameras also have a lot of pixels on that sensor, then you will get an increase in noise levels the higher up you go via ISO settings. This is why most compacts will give excellent results at ISO 50, 100, and possibly 200, but will show noise levels at 400, and high noise levels at 800. This noise level depends upon the camera you have as some are better at controlling noise then others. I have seen some compacts give unacceptable noise levels at ISO 200, others right up to 400 or 800.

    Pixel relationship explained.

    This is where DSLRs are best. Their larger image sensor size will allow you to increase sensor sensitivity with little noise. Some can give you acceptable photos right up to ISO 3200. A far cry from the measly ISO 400 rating that most compacts can give you.

    This is why DSLR cameras excel at low light photography, and why compact cameras do not.

    So the next time your looking for a digital camera and you see that nice compact camera...just think about the megapixel count. There is a good reason why many are holding at around the 6 megapixel count. This is because it is currently the sweet spot for low light performance and image quality. Now if you don't care about low light photography (with no flash)..then by all means..go get that 10 megapixel monster and be happy with the increased resolution and cropping power.









    No photographer is as good as the simplest camera. ~Edward Steichen

  2. #2
    Senior Member Paully's Avatar
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    Default Re: Digital Camera Noise Explained

    This is one factor I really found in the fujifilm e900 however being a 9 megapixel, my 8 megapixel DSLR Smokes it.

    nice review grab!

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