One of the criteria that every camera review site uses in evaluating the quality of a new camera is image noise. As ISO increases noise normally increases as the sensor capture capabilities (or lack thereof) and boost processing electronics take their toll on the quality of the captured image.

There are many things that affect that noise, not the least of which is the size of the light-gathering pixels that capture the image. As discussed in detail in The Digital Sensor and The Digital Sensor Part 2, the size of the photosite is the reason the tiny sensors used in pocket point and shoot cameras are so limited in capabilities compared to the Digital SLR, which is where the major growth in the photographic market is now occurring.


The impact of photosite size is ably demonstrated in one of today's hottest DSLR cameras - the Nikon D3. This $5000 camera is a 12.2MP full-frame camera. Since it can also handle Nikon DX crop lenses and create a 5MP image at the common APS-C size seen in most of today's DSLR cameras, it is easy to understand that this 12MP full-frame has the same photosite size as a 5MP crop-sensor DSLR.

As discussed in detail in the Digital Sensor articles, the sensor is an analog light-gathering device. It is not a simple digital on-or-off digital device where size really matters very little. In a camera sensor the light gathering is analog and the larger the light gathering area, all else being equal, the better the light gathering ability.

Compared to today's 10 to 14.6MP sensors in top DSLR cameras with a 14x24 sensor, the Nikon D3 has huge photosites in its 24x36mm 12MP sensor. Combined with CMOS technology and evolved electronics the Nikon D3 has a normal ISO range to ISO 6400. As a comparison, the Canon XSI top sensitivity is 1600 and most prosumer models extend to ISO 3200.


As you can see in this dramatic ISO 6400 hockey shot produced by Dave Black for Nikon, D3 images at ISO 6400 are extremely low noise. Even more impressive is the ability to still capture usable images at ISO 12800 and all the way to ISO 25600 with much increased noise in a pinch.

Clearly noise is related to the size of pixels in analog sensors, but that is only part of the story. Often the manufacturer of the camera has made decisions, either informed or due to lack of expertise, to not process for noise at high ISO. Cameras that appear to exhibit much increased noise at high ISOs are sometimes capable of much lower noise. The poor noise performance is sometimes the result of decisions by the camera maker in how files will be converted to RAW or JPEG files in camera or in post-processing software.

The Sigma SD14 Wakeup Call
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  • mharris - Monday, July 28, 2008 - link

    If you look at the photos, you'll notice that the unfiltered photos are nearly 10x bigger than the filtered photos. So the loss of details is due to a ridiculously low JPEG compression, not the noise filter. Reply
  • B3an - Friday, August 1, 2008 - link

    "If you look at the photos, you'll notice that the unfiltered photos are nearly 10x bigger than the filtered photos. So the loss of details is due to a ridiculously low JPEG compression, not the noise filter."

    Not it's not. Would have thought this was obvious... the file size is lower because of the lower detail in the noise reduction filtered images. This is because of how JPEG compression works. It's the same with any image after noise reduction has been used, it nearly always produces smaller files sizes 'cause of the resulting lower detail.
    Reply
  • Baviaan - Monday, July 28, 2008 - link

    Are you actually serious? You can't be, look at the amount of detail lost in the photos done by Noiseware. You lose all the detail and the photos look very, very smeared.

    And compare the 3D to a 1DMK3 or 5D, this comparison is useless.
    Reply
  • Wesley Fink - Monday, July 28, 2008 - link

    There is no doubt the Nikon D3 is the low-noise champion, but we weren't comparing it to other PRO cameras like the ID Mark III. The comments were comparing relative photosire size across the spectrum of digital SLR sensors.

    We do agree the ID Mk III at 10 megaixel with a 1.3X (APS-H) crop factor is more directly comparable in photosite size to the D3. The 5D at full-frame 12.8 megapixels is certainly comparable in photosite size if not speed or high ISO performance.
    Reply
  • strikeback03 - Monday, July 28, 2008 - link

    The 5D is only enabled on-camera to ISO 3200, but plenty of users use effectively higher ISOs by deliberately underexposing then pushing the exposure in post-process with decent results. Reply
  • michal1980 - Monday, July 28, 2008 - link

    I agree with others.

    Are you guys blind? some of thos vacation shots are terrible after the noise reduction. I'd rather stick with the noise in some of them. The beach shot looks ok in the foreground, but as soon as you hit the water its all water paiting.

    the sail boat on the water is one of the worst, in the original shot you see waves breaking, and caps. The after processing shot destroy's the feel of the water.

    IMHO, alot of the pictures looks better just shrunk (which filter the nose by itself), then they did after noise removal.
    Reply
  • Jedi2155 - Monday, July 28, 2008 - link

    Same here, there noise reduction seriously destroys the detail present in the images. A lot of the areas of high contrast is destroyed after the noise reduction resulting in smearing.

    I'm neither a professional or even a prosumer, but it was quite noticeable to me that the details were significantly reduced with the noise reduction where I definitely would not consider this software.

    I also could not tell the difference in the low ISO shots for the noise reduction although I am on a 6-bit TN LCD panel so that could probably be the reason. Did anyone else see a difference in the low-ISO shots?
    Reply
  • B3an - Monday, July 28, 2008 - link

    From the images it's hardly any better than Photoshops noise reduction filter. Messing around with the settings i can get very nearly as good results.

    And like all noise reduction filters it makes the image lose detail, messes up some colours, and sometimes over sharpens the edges.

    I dont think this is good software or worth the money.
    Reply
  • eetnoyer - Monday, July 28, 2008 - link

    Noiseware on images from any of the superzooms? I often find myself to be a little tentative of taking higher ISO setting shots on my superzoom because of the pronounced noise levels. I would be interested to see some results from some of the different brands' superzoom models.

    Thanks
    Reply
  • guitargeek27 - Monday, July 28, 2008 - link

    All in all, I've been pretty disappointed in the Anandtech articles about cameras and image manipulation, the articles gives just a rough idea what noise reduction software does, but does not go into settings, original noise levels, or RAW vs JPEG noise levels (lens, apeture, shutter speed, post processing software).

    If you're a beginner photographer, or just care about software please read. But if you are seriously interested in photography please try a different site or get your hands on a real book.

    I think I'm just disappointed about having an amateur write a review as opposed to a pro.
    Reply

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