Archived posting to the Leica Users Group, 2013/05/19

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Subject: [Leica] To tempt Fuji X users?
From: abridge at mac.com (Adam Bridge)
Date: Sun, 19 May 2013 15:33:23 -0700
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Very clear, Bob, thank you!

I've seen the translucent white covers but only thought of them for white 
balance and not for lens cast.

I didn't know it applied to the Alpa. Is it also the case for say medium 
format cameras or is this a technical camera domain issue?

Adam

On May 19, 2013, at 1:37 PM, Robert Adler <rgacpa at gmail.com> wrote:

> Hi Adam,
> As I understand it, as you go out further towards the edges of an image
> circle, the reds, greens and blues hit the pixel sights at ever increasing
> (in nano seconds no doubt!) increments. Thus the colors begin to separate.
> You start to to get more red and less green as you go further out. I
> actually have to address this quite significantly on my Alpa because I move
> the digital back from right, to middle to left across the image circle for
> a pano It is known that "lens cast" is a problem for MFDB on tech cameras
> where shifting is used quite often. CaptureOne has a Lens Cast Correction
> feature just for this.
> 
> At some point in shooting a venue, I put an opaque white piece of plastic
> in front of the lens. I then take an exposure, usually two stops more open
> than the exposure that I'm using for the image; and using the shutter speed
> to open up, not the aperture). These LCC shots are then used in CaptureOne
> to even out both the vignetting and the color cast. I also use the middle
> of the shot that is taken through this opaque device as a white balance and
> it works pretty well.
> 
> Seems Fuji has somehow allowed a user to adjust in the camera for third
> party lenses that aren't already corrected by them and that are using their
> X mount to M mount adapter.
> Clear as mud? :-)
> Bob
> 
> 
> On Sun, May 19, 2013 at 8:51 AM, Adam Bridge <abridge at mac.com> wrote:
> 
>> On May 18, 2013, at 8:12 AM, Robert Adler <rgacpa at gmail.com> wrote:
>> 
>>> If it a Fuji adapter supported lens, there are built in adjustments for
>>> distortion (barrel/pincushion), color separation and light falloff. This
>>> information is passed in the metadata with the RAW file and can be read
>> by
>>> ACR/CaptureOne/Aperture (all accept the color separation unfortunately,
>> but
>>> this can be corrected in various 3rd party software if needed).
>> 
>> Bob, I don't understand "color separation" in this list of items.
>> 
>> Is that like color temperature?
>> 
>> Adam
>> 
>> 
>> _______________________________________________
>> Leica Users Group.
>> See http://leica-users.org/mailman/listinfo/lug for more information
>> 
> 
> 
> 
> -- 
> Bob Adler
> 
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information



Replies: Reply from rgacpa at gmail.com (Robert Adler) ([Leica] To tempt Fuji X users?)
In reply to: Message from amr3 at uwm.edu (Alan Magayne-Roshak) ([Leica] To tempt Fuji X users?)
Message from rgacpa at gmail.com (Robert G Adler) ([Leica] To tempt Fuji X users?)
Message from red735i at verizon.net (Frank Filippone) ([Leica] To tempt Fuji X users?)
Message from frank.dernie at btinternet.com (FRANK DERNIE) ([Leica] To tempt Fuji X users?)
Message from rgacpa at gmail.com (Robert Adler) ([Leica] To tempt Fuji X users?)
Message from abridge at mac.com (Adam Bridge) ([Leica] To tempt Fuji X users?)
Message from rgacpa at gmail.com (Robert Adler) ([Leica] To tempt Fuji X users?)