Camera Labs

in several of the low-end point & shoot cams, there are choices under the "P" mode, e.g. ISO setting. as i read that the low end cameras distort the image when the ISO is set too high, am not understanding how change of ISO "sensitivity" affects the camera sensor operation.

As ISO goes up - so does the noise. The reason for increasing ISO is to reduce the shutter speed, but it does come as a cost of the aforementioned noise.

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Trevor Harris

Nikon D200
SB-600
YN-560 II
YN RF 603 x 4
Tamron 17-50mm f/2.8
Nikon 50mm f/1.8

When you increase the ISO you increase the signal output from the sensor, and that includes the noise from the electric charge running through it.
Here's an analogy: For a P&S with its tiny sensor it's like trying to push massive sound (lots of megapixels) through a tiny speaker (small sensor). The result will not be very clean. The smaller the speaker the more pronounced to undesired noise will be

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Canon DSLRs: 5D Mark III, 7D
Canon lenses: 17-40/4L, 24-105/4L, 24/1.4L II, 50/1.4, 85/1.8, 100/2.8L Macro, 70-200/2.8L IS, 100-400L
Other stuff: Canon 580 EX II, Canon 430EX II, Velbon Sherpa 600R
Apple: MacBook Pro 15", iMac 27", iPad III, iPhone 4S, Apple TV

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