Archived posting to the Leica Users Group, 2006/10/12

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Subject: [Leica] LHSA meeting in Wetzlar; Leica Camera AG
From: hoppyman at bigpond.net.au (G Hopkinson)
Date: Thu Oct 12 15:46:39 2006

Thanks Frank, that certainly makes sense that there would be no compelling 
reason to want to remove the vignette correction. This
from the DP Review suggests that the correction is applied to the RAW files. 
"Know which lens is being used and apply some software
correction - all new M series lenses now carry a six-bit code which allows 
the M8 to identify which lens is used and (optionally)
apply a 'final stage' software based vignetting correction (for RAW images 
the lens used is simply recorded, no change is made)".
I understand and agree that this will happen in the camera. Nevertheless, IF 
it was optional to apply when using RAW files, then if
would be surprising if Photoshop for example, did not add an ability to do 
it their own way. We already have perspective correction
ability in the latest Photoshop, for example. Corner dodging/burning is well 
established in plug-ins as well, for example Photokit.
My speculation would be that the actual correction may be the same for whole 
groups of lenses. For example all of the fifties may be
perfectly served by a single in-camera correction?
As you said just wait until some production cameras get out there and we 
shall all see.
Thanks
Hoppy

-----Original Message-----
From: lug-bounces+hoppyman=bigpond.net.au@leica-users.org 
[mailto:lug-bounces+hoppyman=bigpond.net.au@leica-users.org] On Behalf Of
Frank Filippone
Sent: Thursday, 12 October 2006 23:45
To: 'Leica Users Group'
Subject: RE: [Leica] LHSA meeting in Wetzlar; Leica Camera AG

Well, my thoughts are that the camera records the corrected data AS the RAW 
file.  Yes, the EXIF may tell you which lens, but
basically, the corrections are already done.  I guess you could go backwards 
and un-correct in the computer, but why?

Think of this as correcting a lens aberration.  After the engineer has 
corrected out the aberration, why would you ever want to put
it back in?  Why would you allow the user to fiddle with the control?

I think there is a more compelling reason to build it into the camera.... 
Then you do not need to hire some programmer to write a
special add in for some ( or MANY !!!!) computer programs to make it 
actually work, then maintain that software for all eternity on
all the platforms, and with several versions of SW revisions....  Given that 
this is the first ( and maybe only for the forseeable
future) camera company to need or employ individual pixel gain calibration, 
it is not an easy job to convince PS to incorporate it
into their program.  It would need to be supported by Leica.  Personally, 
this would be my reason to build it into the camera, if I
were King.

I have always thought that 6 bits, or 64 different algorithms sounded small 
for all the past lenses, plus all future lenses from
Leica.  If corrections were based upon FL, then you might need.. ( 14, 16, 
18, 21, 24, 28, 35, 50 )  something like 8 different
states for the indicator... not 64.  If it were based upon angle of optical 
rays, then each lens design would require its  own
correction algorithm.  64 sounds small....  ( 14, 16, 18, 21 Tri-E, 21 SA, 
21 Elmarit, 21 ASPH; 24 Elmarit, 24 ASPH, 28 Elmarit V1,
V2, 28 ASPH Summicron, 28 ASPH Elmarit, 4 versions of the 35 Summicron, 3 
versions of the 35 Summilux, ASPH versions of each, 10
versions of 50 Summicron and other F2, another 6 or so versions of the 50 
Summilux, etc etc....) but maybe that is right...

As soon as someone has a real life camera, this question will be quickly 
answered......

Frank Filippone
red735i@earthlink.net 



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In reply to: Message from red735i at earthlink.net (Frank Filippone) ([Leica] LHSA meeting in Wetzlar; Leica Camera AG)