Archived posting to the Leica Users Group, 2014/07/02

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Subject: [Leica] OT: Fuji X file sizes
From: hlritter at bex.net (Howard Ritter)
Date: Wed, 2 Jul 2014 16:41:54 -0400
References: <F4089BDF-D730-4E7F-903C-55C0C9AF5067@frozenlight.eu> <MS1f1o02707g8Sg01S1g5E> <53B4483C.9040201@cox.net>

This file-size difference is intrinsic to TIFF, which interpolates a value 
for all 3 colors, R-G-B, for each pixel.

The X-Pro 1 has a 24-Mpx sensor, 8 million for each of R, G, and B (this is 
simplified), each of which generates 1 byte of luminance information. So its 
raw (adjective, not acronym!) file size is 1 byte x 8 Mpx x 3 colors?to a 
first approximation, 24 MB. If JPEGed for storage, it is re-expanded when 
viewed. When the image is viewed or printed, software gives each R photosite 
also a G and a B value by interpolation from adjacent G and B photosites, 
and likewise for native G and B photosites. So the full image you see in 
Photoshop should have a file size of ~72MB. TIFF is simply this full file, 
with interpolated colors at each pixel. That's why it's always generally 
about 3 x the size of the stripped-down raw file. Differences seen in 
practice may result from compression, which can save significant storage 
capacity without loss of information (unlike JPEG). There may be some 
housekeeping stuff that brings your TIFF file to 4 x your raw; perhaps the 
file also incorporates a separate raw image.

I don't know how this relates to DNG, though.

?howard


On Jul 2, 2014, at 1:58 PM, Ken Carney <kcarney1 at cox.net> wrote:

> I hadn't really looked either.  My X raw files are about 24-27 MB (not 
> sure what causes the size differential), opening to 94MB Tiff's.   My 
> Canon 5D MkII files are roughly the same raw size, but open to 120+ MB 
> Tiff's.
> 
> Ken


Replies: Reply from hopsternew at gmail.com (Geoff Hopkinson) ([Leica] OT: Fuji X file sizes)
In reply to: Message from kcarney1 at cox.net (Ken Carney) ([Leica] OT: Fuji X file sizes)