Help with aspect ratio please

Hi,
I have a canon s100, default setting is 4:3, my Son just bought a Sony rx100, and the default is 3:2........why the difference?

Help

The default is usually determined by the native aspect ratio of the sensor. Read the specification section of your manual to verify the sensor dimensions. Virtually all of the sensor sizes given as one of those ever-so-helpful "1/n.nn inch" dimensions used for most compact cameras have a 4:3 native aspect ratio.

Some cameras allow you to set another aspect ration, but this is done by in-camera cropping, i.e., using only part of the sensor. You'll have better control by shooting in the native aspect ratio and cropping in post processing.

If your camera does have one of the 1/n.nn inch sensor sizes, post it here and I will give you the approximate real sensor dimensions in mm.

20droger wrote in post #16329900
The default is usually determined by the native aspect ratio of the sensor. Read the specification section of your manual to verify the sensor dimensions. Virtually all of the sensor sizes given as one of those ever-so-helpful "1/n.nn inch" dimensions used for most compact cameras have a 4:3 native aspect ratio.

Some cameras allow you to set another aspect ration, but this is done by in-camera cropping, i.e., using only part of the sensor. You'll have better control by shooting in the native aspect ratio and cropping in post processing.

If your camera does have one of the 1/n.nn inch sensor sizes, post it here and I will give you the approximate real sensor dimensions in mm.

I will check, but I know the sensor size on my g1x is bigger that both the s100 and the Sony r100, both the canon defaults are 4:3, but the Sony is 3:2?

Mark, the 3:2 aspect ratio is what's been used for most 35mm film cameras (and most DSLRs) for a long time. It could be that the Sony engineers and marketing folks felt that customers would like to have the same 4"x6" prints made from their work as they did when they used a 35mm point-n-shoot camera in days past.

Okay, I've had a little spare time, so I looked up your cameras' sensors

Canon PowerShot G1 X:
1.5" (18.7 × 14.0mm) sensor; 4:3 aspect ratio
slightly larger than a micro four-thirds sensor, slightly smaller than a Canon APS-C 1.6× sensor

Sony Cyber-shot RX 100:
1.0" (13.2 × 8.8mm) sensor; 3:2 aspect ratio
smaller than a Canon G1 X sensor, but with the same aspect ratio as a Sony DSLR cameras

Canon PowereShot S100:
1/1.7" (7.60 × 5.70mm) sensor; 4:3 aspect ratio
typical small sensor for compact camera

These inch-sized sensors all have sizes that originated with the old Vidicon tubes formerly used in television cameras. At the time, a standard television image had a 4:3 aspect ratio, and most of such inch-sized compact camera sensors carried the "tradition" forward, so that an image wi\ould fit perfectly on a standard TV screen or a traditional CRT computer monitor.

The Sony RX 100, on the other hand, was an exception developed as a "scaled-down DSLR" replacement. Its sensor therefore has a 3:2 aspect ratio in imitation of the standard DSLR aspect ratio, derived from the days of 35mm film SLR cameras.

In the future you can expect more and more P&S cameras with 3:2 or even 16:9 native aspect ratios.

mark2009 wrote in post #16329976
I will check, but I know the sensor size on my g1x is bigger that both the s100 and the Sony r100, both the canon defaults are 4:3, but the Sony is 3:2?

Mark, sensor size and sensor resolution has nothing to do with the aspect ratio. The size is the size, that is the area captured by the sensor. The resolution will reflect the size and then the resolution of the sensor, in which a larger sensor gives a better resolution as a combination of more pixels and often better-quality pixels.

The aspect ratio is simply a determination of how the sensor "frames" the images. It is determined by the physical dimensions of the sensor or, as has been mentioned, by an in-camera "framing".

For web posting/sharing the camera's native aspect ratio is by and large irrelevant and aesthetic considerations are foremost in determining a crop that departs from the original A.R. However, when making prints the paper's aspect ratio is the major determinant and many standard American shapes, like 5x7, 8x10, or 11x14 are neither 2:3 nor 3:4. These paper sizes are traditional, some of them reaching back 150 years to the days before film, when the photographic emulsion was coated on glass plates that came in those sizes. Because of the need to crop the out-of-camera image to conform to the paper's shape, it is difficult to declare either 2:3 or 3:4 as the superior choice.

In Europe photographic papers have adopted the standard aspect ratio for stationary paper, 1:sqrt2 or 1:1.414.

Ok, thanks to all, makes sense now.