A80 - Why only 1.5MB pictures ?

[Korbo]

I took some pics with an A80 and only got 1.5MB pics on the "Best" picture quality setting.

Shouldn't a 4 M-pixel camera get at least 2MB pics?

[George Riehm]

I took some pics with an A80 and only got 1.5MB pics on the "Best" picture quality setting.

Shouldn't a 4 M-pixel camera get at least 2MB pics?

"Fine" or "Best" compression is generally 6 to 8 times, so your camera is within the normal range. Totally uncompressed the file size would be 12MB.

[Korbo]

"Fine" or "Best" compression is generally 6 to 8 times, so your camera is within the normal range. Totally uncompressed the file size would be 12MB.

Thanks ... what is the general rule of thumb for the proper ratio range of Megapixels to compressed MB of memory for "Best" mode?

[George Riehm]

Thanks ... what is the general rule of thumb for the proper ratio range of Megapixels to compressed MB of memory for "Best" mode?

As per your original message it's approx. 1.5MB = 4MP image= 8:1 compression.

A 4MP image has 12MB of information as the sensor has Red, Green, and Blue data for each pixel. 4MB x 3 colors = 12MB. (and 5MP = 15MB, etc).

[Rhys]

As per your original message it's approx. 1.5MB = 4MP image= 8:1 compression.

A 4MP image has 12MB of information as the sensor has Red, Green, and Blue data for each pixel. 4MB x 3 colors = 12MB. (and 5MP = 15MB, etc).

It's not as simple as that though...

Look at the number of bits on the camera. They should be 24 bit, 32 bit or more. As an example, an LCD monitor is 16 bit. That's 2 bytes per pixel. I believe most digital cameras are 24 bit or 3 bytes per pixel.

This means that each pixel is 4 bytes so 4 x 3MP = 12MB and 4 x 4MP = 4MB.