Archived posting to the Leica Users Group, 2006/05/25

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Subject: [Leica] Re: Visual compression
From: abridge at gmail.com (Adam Bridge)
Date: Thu May 25 17:41:29 2006
References: <200605251856.k4PIuFJ8017725@server1.waverley.reid.org> <5259b99f7b3ec4704c693ae291a469cc@optonline.net>

I think you've set up a bit of a straw-horse, Lawrence. Capturing in
RAW gives you substantial advantages when combining channels into a
higher bit-depth image - ie getting a 16 bit image space instead of an
8 bit space.

This is especially important in digital because of the limited dynamic
range available and your ability to correct in difficult exposures
that would be impossible to correct in a JPEG file.

After you've done all that correction  you can save the final image as
an 8 bit image in whatever format pulls your chain and at whatever
pixel density you choose, but ultimately it's how you start that has
the biggest effect on outcome and starting with RAW is important.

Adam


On 5/25/06, Lawrence Zeitlin <lrzeitlin@optonline.net> wrote:
> All you RAW addicts, don;t sneer at JPEG compression. An article in the
> latest issue of Science (Vol 312, Issue 5777) suggests that the eyes
> 125,000,000 cones and rods activate only 1,200,000 individual fibers in
> the optic nerve. This is a 10 to 1 compression ratio.
>
> If this is the case, then a 1.2 meg. RAW image contains all the
> information that the eye can see.
>
> Makes one wonder about the race to higher and higher pixel counts.
>
> Larry Z
>
>
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> Leica Users Group.
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>


In reply to: Message from lrzeitlin at optonline.net (Lawrence Zeitlin) ([Leica] Re: Visual compression)