what's the difference between megapixels and "effective" megapixels?

[Lifer]

 

[jvang125]

just plain megapixel means the maximum number of pixels on the CCD image sensor. effective megapixels means the number of pixels that are actually used to render and produce the image. effective megapixels is a much more accurate measurement.

 

[Wiktor]

Some Fuji cameras have this special CCD technology are you talking about one of these?

 

[Mark R]

Most digicams have a number of 'extra' pixels on the image sensor - these are permanently covered are used by the camera to calibrate the sensor for pure black.

These are sometimes counted in the advertising literature. 'Effective megapixels' counts only pixels whose output is used directly to produce the image.

This is slightly different to fuji's cameras which are e.g. 3 effective megapixels, but have a 6 megapixel output. In a conventional digicam the pixels on the sensor are arranged in a grid, and directly correspond to the arrangement of pixels in the final image. Fuji use hexagonal pixels in their sensor - when the image is produced each sensor pixel is interpolated into 2 pixels in the final image

 

[bigpow]

just another marketing crap.

Always check their lower spec.


media size, 1 byte = 1000 bytes instead of 1024
CRT Monitor physical Vs viewable size
Athlon XP 3200+ that runs at 2.xx GHz (getting worse & worse with newer cores)
Speaker power peak-to-peak/PMPO Vs RMS

 

[thorin]

Marketing BS.

It's just like scanners being 32bit optical/48bit enhanced.

When buying you should care about actual not effective.

Thorin

 

[Lifer]

so is it actual or effective that's the true rating?

like RMS = actual, PMPO = effective?
or is it the other way around?

 

[Mark R]

Effective is the figure that most directly relates to image quality.

 

[Lonyo]

Normally effective is the lower of the 2 numbers (32/48-bit scanners, RMS is real, PMPO is higher) etc.
RMS = Root mean square
PMPO = Peak maximum power output (so it would be like using max frame rate rather than average in a game benchmark, I guess)

 

[Mingon]

Normally effective is the lower of the 2 numbers (32/48-bit scanners, RMS is real, PMPO is higher) etc.

They used to be advertised as;

RMS - Real music sound
PMPO - peak music power output

 

[Mday]

Originally posted by: Wiktor
Some Fuji cameras have this special CCD technology are you talking about one of these?

"super ccd" is what fuji has, they use hexagonal geometry instead of square so each pixel actually has more than one sensor attached to it. they use special software techniques to interpolate it up to about 2x the effective megapixel rating. so, when they had a 3 megapixel camera, they can produce 6 megapixel pictures with this upsampling. in terms of picture quality, the 6 megapixel version is less stellar than a real 6 megapixel image. however, the 3 megapixel image is among the better 3 megapixel images.

"effective" megapixel is the size of the image you can take max without any special software. this is NOW the current measurement of cameras. the use of
megapixel to say otherwise is no longer done due to industry standard advertising "standards" using "effective megapixel" as the actual methodology to label cameras. in other words, effective megapixel is what you are buying.

actual megapixel may be higher due to lost pixels in the use of smaller optics or masked pixels for "black". some pixels are covered to allow no light to enter as a basis to determine "black" or base voltages that may occur with the sensors. actual megapixels refer to how many pixels the capturing sensor has (ccd, cmos, or jfet)

case in point: my sony camera has a 5.2 megapixel ccd, but the max image it produces (no upsampling) is 4.92 megapixels. so, it's actual megapixel rating is 5.2, and it's effective megapixel rating is 4.92