megapixels?

Hi my camera a GE A1255 has 12.2 megapixel spec. But I have not seen a pic over 6.2 meg with most around 4 meg,s. what kind of subject would you need to use the 12.2 megs?

Thank,s Rob

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Originally Posted by ct-rob

Hi my camera a GE A1255 has 12.2 megapixel spec. But I have not seen a pic over 6.2 meg with most around 4 meg,s. what kind of subject would you need to use the 12.2 megs?

Thank,s Rob

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MP is the resolution of the image (number of dots). I think that you are looking at the file size, correct? Not the same thing. - TF

Thank,s I thought it was related .

Rob

If you're shooting with JPEG then the size can be as small as 1/3 the expected number of megapixels.
JPEG compressed the image by throwing away parts of it (lossy compression) and if you enlarge them a lot, or go peeking at individual pixels, you may see blocky patterns in areas of more or less the same colour.
Normally it doesn't matter, as your eye/brain tends to fill in the details.

yes their must be a lot of blocky patterns if every pixels data was recorded the file size should not very to much.

Rob

If you set to max, use Fine instead of Economy to get full res, but file size is much bigger.

Color is whats most effected by jpeg compression, not line detail (or, only as it relates to color). Tonal graduations become less and less smooth the greater the compression.

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Originally Posted by Anbesol

Color is whats most effected by jpeg compression, not line detail (or, only as it relates to color). Tonal graduations become less and less smooth the greater the compression.

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That is interesting. Are you saying FINE pics are more colorful than ECONOMY?

6mp, Economy, file size 1.1mb, zoomed 200%, distortion and halo around edges.
Same scene, 6mp Fine, file size 3.56mb, zoomed 200%, looked ok, less distortion.
In fact, if you have to zoom that much to see so little difference between Fine and Economy, it's not worth it to use Fine at all as file size is 3x. I use Normal as I found burst mode using Fine useless as it took too long to save to card.

In fact, I am not certain as to what's happening using Economy, if compression is used then it would take longer to save pics vs. Fine; In fact, opposite is true.

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Originally Posted by Romphotog

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In fact, I am not certain as to what's happening using Economy, if compression is used then it would take longer to save pics vs. Fine; In fact, opposite is true.

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The file size is bigger with Fine. The bottleneck is not the processing of the image, it's the time taken to write the result to your memory card. In burst mode you're filling up the camera buffer with several images then having to wait while it flushes all the JPG's to card.

BTW I've never noticed any difference in the colour between more or less compressed JPG's. I find the difference is in fine detail like blades of grass.

thank you:) :)