Hi,
On Wed, 2008-03-19 at 14:16 +1100, David Hodson wrote:
> Should be easy(-ish) :
>
> Split image into red, green, blue channels.
> Apply lens correction to red and blue channels to align with green.
> Recombine channels.
That would work well if the light was combined out of exactly three
wel
norman wrote:
> I have been copying some old colour transparencies using my digital
> camera and most of the images produced suffer from chromatic aberration
> somewhere within them. I have tried to find some procedure to remove
> these blemishes but, so far, have not found anything I can get to wo
Simon Roberts wrote:
> See Ken Rockwell's comments on "it's not the camera" at
> http://www.kenrockwell.com/tech/notcamera.htm
>
An excellent discussion, although Rockwell fails to mention Ansel
Adams's darkroom artistry (see wikipedia on Ansel Adams and the
associated reference 18).
__
* norman <[EMAIL PROTECTED]> [03-18-08 10:53]:
> < snip >
> >
> > Unfortunately, ca is controlled in lense manufacture and design and
> > has two solutions, software or better glass. Minimizing ca via
> > technique would severly limit your scope, imo.
>
> I would expect most lenses these days to
On Tue 18-Mar-2008 at 16:23 +, norman wrote:
>
>> http://wiki.panotools.org/SoC_2008_ideas#tCA_Correction
>
>This seems to assume that the optics are the cause of the CA whereas I
>understand that CA is also caused by the chip in e digital camera. Will
>this process take care of that?
Nope.
-
-
< snip >
> Are you "copying" the slides, or are you scanning them?
>
> If you're using a slide copying attachment and effectively rephotographing
> them onto your digital camera, then the CA of the copying equipment will be a
On Tue, 2008-03-18 at 15:33 +, norman wrote:
> I feel sure that you must be correct. I have never seen any noticeable
> fringing or CA effects with my ordinary photography it is only with
this
> project I set myself of copying a lot of old colour transparencies. In
> the old days I used to of
On Tue, 2008-03-18 at 16:23 +, norman wrote:
> On Tue, 2008-03-18 at 15:46 +, Bruno Postle wrote:
> > On Tue 18-Mar-2008 at 08:13 -0700, Simon Roberts wrote:
> > >
> > >Software can certainly help with this, and "that other product" has
> > >this built in. Then again, you can buy a coupl
On Tue, 2008-03-18 at 16:23 +, norman wrote:
> On Tue, 2008-03-18 at 15:46 +, Bruno Postle wrote:
> > On Tue 18-Mar-2008 at 08:13 -0700, Simon Roberts wrote:
> > >
> > >Software can certainly help with this, and "that other product" has
> > >this built in. Then again, you can buy a coupl
- Original Message
From: norman <[EMAIL PROTECTED]>
...
> CA is indeed a function of the lens quality. You're also right that a smaller
> sensor makes CA more visible, that's just simple geometry. If the lens
> produces an abberation of any given size, then if the sensor is half the
>
On Tue, 2008-03-18 at 15:46 +, Bruno Postle wrote:
> On Tue 18-Mar-2008 at 08:13 -0700, Simon Roberts wrote:
> >
> >Software can certainly help with this, and "that other product" has
> >this built in. Then again, you can buy a couple of really nice
> >lenses for the price you'll pay for tha
On Tue 18-Mar-2008 at 08:13 -0700, Simon Roberts wrote:
>
>Software can certainly help with this, and "that other product" has
>this built in. Then again, you can buy a couple of really nice
>lenses for the price you'll pay for that product ;>
Not an immediate solution, but 'over at the hugin pr
On Tue, 2008-03-18 at 08:13 -0700, Simon Roberts wrote:
>
> - Original Message
> From: norman <[EMAIL PROTECTED]>
> To: gimp-user@lists.XCF.Berkeley.EDU
> Sent: Tuesday, March 18, 2008 8:52:22 AM
> Subject: Re: [Gimp-user] chromatic aberration
>
> < sni
- Original Message
From: norman <[EMAIL PROTECTED]>
To: gimp-user@lists.XCF.Berkeley.EDU
Sent: Tuesday, March 18, 2008 8:52:22 AM
Subject: Re: [Gimp-user] chromatic aberration
< snip >
>
> Unfortunately, ca is controlled in lense manufacture and design and
&
< snip >
>
> Unfortunately, ca is controlled in lense manufacture and design and
> has two solutions, software or better glass. Minimizing ca via
> technique would severly limit your scope, imo.
I would expect most lenses these days to be made such that they do not
cause CA. From what I have rea
* norman <[EMAIL PROTECTED]> [03-18-08 09:46]:
> Therefore, I believe what I should do is concentrate on photographic
> techniques with a view to minimising the chromatic aberration as much
> as possible. Any advice in this direction would be very welcome.
Unfortunately, ca is controlled in lense
Thank you very much for trying to help me sort out the problem. It looks
very much as though any procedure would be both complex and time
consuming without any guarantee of success. Therefore, I believe what I
should do is concentrate on photographic techniques with a view to
minimising the chromat
I think there used to be a plugin in the registry for doing this, but I can't
remember
the name of it. Dunno if it would work in 2.4 or not.
--- norman <[EMAIL PROTECTED]> wrote:
> I have been copying some old colour transparencies using my digital
> camera and most of the images produced suff
Given a sample image I can be more specific than the following:
1 Decompose the image into LAB channels.
2 Despeckle the AB channels (oilify with low exponent is also an option)
3 Recompose
On Tue, Mar 18, 2008 at 6:44 AM, Jeffrey Brent McBeth <[EMAIL PROTECTED]> wrote:
> On Mon, Mar 17, 2008 at
On Mon, Mar 17, 2008 at 03:09:47PM -0500, Chris Mohler wrote:
> On Mon, Mar 17, 2008 at 1:39 PM, norman <[EMAIL PROTECTED]> wrote:
> > I have been copying some old colour transparencies using my digital
> > camera and most of the images produced suffer from chromatic aberration
> > somewhere with
On Mon, Mar 17, 2008 at 1:39 PM, norman <[EMAIL PROTECTED]> wrote:
> I have been copying some old colour transparencies using my digital
> camera and most of the images produced suffer from chromatic aberration
> somewhere within them. I have tried to find some procedure to remove
> these blemis
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