Megapixels
- Thread starter BooBoos
- Start date
D12345678
Senior Member
Unfortunately it seems your original question has been lost by other discussion about resolution, file sizes and printing etc...
OK, The megapixel size of your camera's sensor has little to do with the file size of a jpeg that's shot. The file size of the jpeg is more to do with "bits" of information that go into making up the image (jpeg). For example, if you take a photo of a piece of white paper your jpeg may only end up being 1mb or even less. If you take a photo of a sunrise at the beach the jpeg may end up being somewhere around 3 or 4mb. If you take a landscape photo with lots of different trees, leaves, mountains, clouds and other detailed features it means there'll be more bits of information in the jpeg image and it may end up being around 8 or 9mb in file size.
Is that more like you were asking about?
dSLR do not work this way, each pixel has to report a value regardless whether that value equals a white pixel (in your paper example) or some other color pixel. Moreover, a pixel reporting a white value number does not represent non-data, it's a color value and requires a numerical number to be generated. In fact, a blank piece of paper is not "white" and each paper type is different. Some have a tanish hue while others have a yellowish-ness to them. On top of that, each "color" data is the sum total of 3 sensors - a red, blu and green sensitive sensor - which all combine to generate a color value. And in the case of a piece of paper, it is not true white at all, rather it is a shade of white. This is why they tell you not to use white paper when setting your WB value and instead to use an 18% gray card.
But to the OP's original point, color does not determine size of file being generated, rather the JPEG compression being used is the determinant of file size. "Fine" produces a less compressed file than "large" produces. In the case of RAW files, the result in a much larger file size because there is no compression (typically) and the file represents the entirety of the data generated by the sensor. In the case of the OP, he was shooting in JPEG "large" believing this was the top setting for his camera instead of shooting in "fine" which is in fact the top setting for his camera. And to complicate things more, a megapixel is a measure of the number of individual light sensitive sensors whereas megabytes (Mp) is a measure of "bytes" of information in a given file. The two very different measurements altogether and do not directly correspond to final file size.
Last edited:
I'm fine with simple answers but any simple answers have to include the right answer.
D12345678
Senior Member
My answer wasn't exactly the wrong answer. While not as technically correct or detailed as your answer, i'm still basically right with what i said, now no one could really disagree with that could they? Personally, i always reckon its best to keep things simple, because it sinks in easier that way. It's true, take a photo of a blank piece of white paper or a clear blue cloudless sky and the end product (in this case, a jpeg) will end up being a smaller file size than a complex landscape or other image with more "stuff" in it!