On 11/2/2014 2:10 PM, John Hudson wrote:
The pixel measurements of the 528,000 kb TIFF are 10,600 x 8,500 pixels giving
90.10 MP total.
That's about right. 10,600 x 8,500 = 90,100,000 Pixels, times 2 bytes per pixel, times three colors per pixel = 90x6 =
540,600,000, = 516 MB*.
The problem with equating that to a Raw file from a digital camera is that they aren't all the same. None of them are 16
bit, some 12, some 14. With a 12 bit per pixel data stream, one may easily put two pixels in three bytes, thus making
writing faster and using less space. (Yes, I've coded bit level combinations of data, back when storage was both small
and slow.)
Also, I think by now pretty much everyone is using compression, all loss-less but for Sony. And the Raw files contain an
embedded JPEG, sometimes full size, sometimes not.
Files from the E-M5 are 4606 x 3456 = 15,925,248 Pixels. If that were 16 bits per pixel, they would be about 31 MB in
size. In fact, they vary from just under 13 to just over 18 MB.
Soooo ... Assuming similar characteristics to an Oly 4/3 file, a Raw file from a digital camera with 10,600 x 8,500
sensor would average about 44 MB. Use a different Raw format from another manufacturer and you will likely get a
different number.
This says nothing about actual resolution of detail. Scanning and direct digital capture are so very different that
comparing raw pixel counts isn't meaningful. I shot a LOT of images with the FF Canon 5D, 4368 x 3912, and scanned many
frames of 35 mm film at 4000 dpi, about 5600 x 3700. The 5D resolved a lot more fine detail.
Mega Numbers Moose
* Remember, pixels and bytes convert to MP and MB by dividing by 1,048,576.
** They aren't comparable between dedicated film scanners and flatbeds, either.
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What if the Hokey Pokey *IS* what it's all about?
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