Sensor size, ISO and sensor technology

[jovijovijovi]

Hi! please move this thread or merge if necessary.

Assumptions? (plese correct): Newer sensors are better at reducing noise caused by high ISO. but high megapixels given the same sensor size causes more noise. But since the sensor technology is newer, it is better at controlling noise.

Therefore If both at a fixed ISO:
40d at 10 MP (older sensor)
50d set at 10 MP (example may option)(newer sensor)

The 50d image is better than the 40d image? Is this true ALWAYS or does another factor affect this?

Thanks!

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[pubert]

some developments why the 50D sensor might be better than the 40D sensor even though individual pixels are smaller:

"The 50D sensor and image processing are a major step forward in what has been a multi-year strategy for Canon to take sensor technology to the limits of physics, simultaneously achieving higher ISOs, lower noise and higher dynamic range.  Note Chuck Westall’s announcement that the 50D sensor has 1 to 1 and a half stops better noise than the 40D sensor despite the smaller pixels.  Several core strategies have been pursued simultaneously for this:

 

• Reducing the micro lens gap to capture all the light hitting the sensor.  This has been highlighted in the 40D, 1D III and 1Ds III sensors and the new 50D sensor now achieves effective 100% coverage.  Only very minor improvements are expected from this point on (e.g. shaping the lenses towards the corners of the frame to capture angled light.)
• Reducing the noise level of each pixel.  Canon have made changes over several generations of sensors to achieve this, bringing the amplifiers closer to each pixel, changing micro-circuit configuration and lowering voltages so the sensor runs colder.  Again the design of the 50D is a big step forward here from the 40D and 1D III etc.  Canon have one more big jump lined up, with low voltage cold running CMOS designs to gain at least an additional stop in lower noise at higher ISOs or long exposures.
• Better digital noise reduction. These are the changes in DIGIC noise processing.  First with the Chroma Noise reduction in DIGIC III and now with more advanced multi-level noise reduction options in DIGIC IV.  Canon believe they have made most of the gains possible via processing algorithms but do still have some areas to develop.  The next focus will be faster noise reduction processing so that it does not come at an impact on frame burst rates (look to the 1D3 replacement for example)

from: http://northlight-images.co.uk/cameras/Canon_5d2_3d_7d.html

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[kengo]

In camera processing are the biggest factor in noise control and not the sensors, so a newer camera with a better image processor will yield photos with less noise.

Ken

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[voodoo]

yes, IQ and noise control would depend a lot on the image processor too (eg. Digic III for canon)

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