On 22/05/2016 07:55, Mort wrote:
Hi,

I would appreciate any comments about this.

I have been using a pair of Canon S-120 pocket cameras for casual and
semi-serious picture taking, especially on the road. I am a long-term
amateur , who remembers working with Kodachrome at ASA 10 and then 25.

I was recently gifted a Canon G7X, which although small is certainly
larger than the S-120. It is said to have a sensor made by Sony that is
larger than that in the S-120 and supposedly allowing sharper images and
better highlight detail.

Scientist that I am, I did some parallel tests under several conditions:
daylight, indoors, flash, distance shots, close-us, etc.. I shoot best
quality JPEG.

I then carefully viewed the images, both on my H.D. screen and with 8x10
prints, utilizing a hand magnifier where necessary.
It really shouldn't be necessary to use a hand magnifier. If your
vision needs correction, wear glasses. If I had a photo on display and
someone wanted to look at it using a hand magnifier, I'd think it was a
bit nuts.
10x8 prints compared - with original images being 12 megapixels and 20
megapixels, then printed at (probably) around 300 pixels per inch,
you're only "seeing" about 7 or 8 megapixels.
On an HD screen you're only seeing about 2 megapixels, if you want to
compare the two side by side on screen, then you're going to have to
view at different output sizes if viewing "actual pixels", or scale one
or the other or both if you want to see them at the same output size.

Even if you were looking for differences and all other things were equal
between the cameras, then there's only about 30% difference in linear
resolution, it should be visible (just) in a real photo at an
appropriately large size, but it won't be a big difference.

I realize the limitations of testing with a series of only one each, but
there is no way that I could test 10 samples of each camera.

In any event, I found no difference in sharpness, color rendition,
contrast range, and highlight details , between the two. Isn't the
camera with a larger and supposedly superior sensor supposed to give
better results? Are other factors, such as lens quality and software in
camera also of major importance?

Thanks.

Mort Linder