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Old Feb 18, 2005, 3:27 PM   #1
ret
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If there is no compression in raw image files, why are they not all the same size? It seems like all CR2 files should be the same size unless the camera is changing something in them.
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Old Feb 18, 2005, 5:37 PM   #2
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There is compression, but it is lossless.
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Old Feb 26, 2005, 3:24 PM   #3
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Also, as I understand it, the CR2 *still* has a jpeg embeded...
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Old Feb 26, 2005, 6:24 PM   #4
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Nope

this is where its different from the old CRW

CRW would embed a jpeg with it, CR2 is pure raw, when you select +jpeg option in the menu, it actually saves a seperate jpeg file, rather than attaching it like in the past.
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Old Feb 26, 2005, 7:29 PM   #5
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There is a tiny jpeg that is included with the cr2 file which can be extracted with a program such as BreezeBrowser (but not with EOS viewer utility). I believe this is the jpeg that is used to display the image thumbnails.

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Old Feb 27, 2005, 3:29 AM   #6
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Thanks BobA. That's why I said *still*...


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Old Feb 27, 2005, 5:30 PM   #7
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Thought the thumnail is what 3KB?
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Old Feb 27, 2005, 5:36 PM   #8
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The thumbnail isn't what's causing the file size difference. RAW has lossless compression, which can result in different RAW file sizes for the same number of pixels. JPEG is a lossy compression, which results in much smaller JPEG files.
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Old Feb 27, 2005, 8:06 PM   #9
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kb244 wrote:
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Thought the thumnail is what 3KB?
It's pretty small, but as I recall I was a bit surprised that it was actually a decent jpeg, so I think it was quite a bit larger than 3KB. I deleted all the ones I made with a trial version of BreezeBrowser ... so I don't have one to check the size.

Ewok: I agree... the tiny jpegisn't the reason for small differences in size of RAW files when all are shot at the same ISO (there are big differences in file size at different ISO settings).



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