5MP vs 7MP...

[bob332]

looking at either a canon s70 or s60, they are close in price, but i believe they have the same size ccd, so is there any problems with going with a higher MP using the same size ccd?either one is more than adequate for my purposes but i was just wondering about this.

thanks

bob

[JimC]

Bob:

As a general rule, the smaller the photosites for each pixel, the higher the noise levels. So, if you put more photosites into the same size sensor (for example, a 5MP 1/1.8" CCD compared to a 3 or 4 Megapixel 1/1.8" CCD) you get more noise (since the photosites must be smaller to fit into the same size CCD when you have more of them, and they are unable to gather as much light, requiring more amplfication for equivalent ISO sensitivity).

However, Sony seems to have made some advances in the CCD design with the new 7MP 1/1.8" CCD that you're seeing in the newer generation of 7MP models from Canon, Sony and others.

Surprisingly, it seems to have lower noise than the Sony 5MP 1/1.8" CCD that Canon uses in the S60 and S50 (which is the opposite of what you would expect). So, I'd probably go with the S70 between these two.

But, if I were choosing between a model using a Sony4MP 1/1.8" CCD versus a Sony 5MP 1/1.8" CCD, I'd personally go with the4MP 1/1.8" CCDif everything else was equal between the models.

[Setiprime]

Got to agree with Jim. One of those little known facts.

[bob332]

JimC wrote:

Bob:

As a general rule, the smaller the photosites for each pixel, the higher the noise levels. So, if you put more photosites into the same size sensor (for example, a 5MP 1/1.8" CCD compared to a 3 or 4 Megapixel 1/1.8" CCD) you get more noise (since the photosites must be smaller to fit into the same size CCD when you have more of them, and they are unable to gather as much light, requiring more amplfication for equivalent ISO sensitivity).

However, Sony seems to have made some advances in the CCD design with the new 7MP 1/1.8" CCD that you're seeing in the newer generation of 7MP models from Canon, Sony and others.

Surprisingly, it seems to have lower noise than the Sony 5MP 1/1.8" CCD that Canon uses in the S60 and S50 (which is the opposite of what you would expect). So, I'd probably go with the S70 between these two.

But, if I were choosing between a model using a Sony4MP 1/1.8" CCD versus a Sony 5MP 1/1.8" CCD, I'd personally go with the4MP 1/1.8" CCDif everything else was equal between the models.

thanks exactly the info i was needing. looks like s70 it is

bob