Chromat Aberration Correction???

I downloaded a trial version of JSC Paint Shop Pro 9.
It includes a tool for CA. I was expecting a routine
to realign the various colors but it appears instead to
merely be some sort of color filter.

Are all CA tools just color touchups, or do some of them
actually realign the various colors' images?

--
Chuck Forsberg www.omen.com 503-614-0430
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 FAX 629-0665

Chuck Forsberg wrote:

I downloaded a trial version of JSC Paint Shop Pro 9.
It includes a tool for CA. I was expecting a routine
to realign the various colors but it appears instead to
merely be some sort of color filter.

Are all CA tools just color touchups, or do some of them
actually realign the various colors' images?

how do you imagine that the perfectly aligned color images,
coming out of the camera perfectly aligned,

would get misaligned?


--
Chuck Forsberg www.omen.com 503-614-0430
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 FAX 629-0665

Chuck Forsberg wrote:

I downloaded a trial version of JSC Paint Shop Pro 9.
It includes a tool for CA. I was expecting a routine
to realign the various colors but it appears instead to
merely be some sort of color filter.

Are all CA tools just color touchups, or do some of them
actually realign the various colors' images?

how do you imagine that the perfectly aligned color images,
coming out of the camera perfectly aligned,

would get misaligned?


--
Chuck Forsberg www.omen.com 503-614-0430
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 FAX 629-0665

Chuck Forsberg wrote:
I downloaded a trial version of JSC Paint Shop Pro 9.
It includes a tool for CA. I was expecting a routine
to realign the various colors but it appears instead to
merely be some sort of color filter.

Are all CA tools just color touchups, or do some of them
actually realign the various colors' images?

Unfortunately how a lens handles light of different wave lengths is why
you get chromatic abberations in the first place. Digital sensors also
contribute to the problem. The colours are not "misaligned" in the first
place, just focused at different lengths and the unfocused 'colour' is
fuzzy and looks larger than the focused colours or it's focused in
different place.

CA can only be corrected after shooting by manipulating the colour which
is causing the fringe in the edge which is offensive. Many programs are
out there to 'fix' CA but all they do is identify the colour abnormality
of edges and remove the offending colour.

Sadly, this often results in an identical colour elsewhere in the image
also being killed. Another point worth considering is that a lot of
'colour fringing' caused by sensors recording against lighter
backgrounds can be mistaken for CA. These purple and sometimes magenta
fringes are much easier to correct with software than true abberations
from a lens.

The 'filters' you can get for Photoshop and others only delete the
colour which offends on the most noticible edge is is on. THat's about
as good as it gets unless your wallet is large for expensive glass and
even then, you can still get CA if you don't know how it occurs and how
to avoid it.

Douglas.

Chuck Forsberg wrote:
I downloaded a trial version of JSC Paint Shop Pro 9.
It includes a tool for CA. I was expecting a routine
to realign the various colors but it appears instead to
merely be some sort of color filter.

Are all CA tools just color touchups, or do some of them
actually realign the various colors' images?

Unfortunately how a lens handles light of different wave lengths is why
you get chromatic abberations in the first place. Digital sensors also
contribute to the problem. The colours are not "misaligned" in the first
place, just focused at different lengths and the unfocused 'colour' is
fuzzy and looks larger than the focused colours or it's focused in
different place.

CA can only be corrected after shooting by manipulating the colour which
is causing the fringe in the edge which is offensive. Many programs are
out there to 'fix' CA but all they do is identify the colour abnormality
of edges and remove the offending colour.

Sadly, this often results in an identical colour elsewhere in the image
also being killed. Another point worth considering is that a lot of
'colour fringing' caused by sensors recording against lighter
backgrounds can be mistaken for CA. These purple and sometimes magenta
fringes are much easier to correct with software than true abberations
from a lens.

The 'filters' you can get for Photoshop and others only delete the
colour which offends on the most noticible edge is is on. THat's about
as good as it gets unless your wallet is large for expensive glass and
even then, you can still get CA if you don't know how it occurs and how
to avoid it.

Douglas.

Kibo informs me that Crownfield stated that:

Chuck Forsberg wrote:

I downloaded a trial version of JSC Paint Shop Pro 9.
It includes a tool for CA. I was expecting a routine
to realign the various colors but it appears instead to
merely be some sort of color filter.

Are all CA tools just color touchups, or do some of them
actually realign the various colors' images?

how do you imagine that the perfectly aligned color images,
coming out of the camera perfectly aligned,

If they were perfectly aligned, there wouldn't be any chromatic
aberration, surely?

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

Lionel wrote:

Kibo informs me that Crownfield stated that:

Chuck Forsberg wrote:

I downloaded a trial version of JSC Paint Shop Pro 9.
It includes a tool for CA. I was expecting a routine
to realign the various colors but it appears instead to
merely be some sort of color filter.

Are all CA tools just color touchups, or do some of them
actually realign the various colors' images?

how do you imagine that the perfectly aligned color images,
coming out of the camera perfectly aligned,

If they were perfectly aligned, there wouldn't be any chromatic
aberration, surely?

and I think you would be incorrect.
the image colors are correctly aligned,
in the center parts of the image,
but probably towards the edge, the color alignment varies
as a function both the color and the distance from center.

're-alignment', better called 'correction'
would be a function of the lens, of the sensor, of the color,
and of the position from the center of the image.

someone already makes such a correction tool.
it also corrects lens distortion.
you buy the correction software in modules
for the camera, and for each lens separately.


--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

Lionel wrote:

Kibo informs me that Crownfield stated that:

Chuck Forsberg wrote:

I downloaded a trial version of JSC Paint Shop Pro 9.
It includes a tool for CA. I was expecting a routine
to realign the various colors but it appears instead to
merely be some sort of color filter.

Are all CA tools just color touchups, or do some of them
actually realign the various colors' images?

how do you imagine that the perfectly aligned color images,
coming out of the camera perfectly aligned,

If they were perfectly aligned, there wouldn't be any chromatic
aberration, surely?

and I think you would be incorrect.
the image colors are correctly aligned,
in the center parts of the image,
but probably towards the edge, the color alignment varies
as a function both the color and the distance from center.

're-alignment', better called 'correction'
would be a function of the lens, of the sensor, of the color,
and of the position from the center of the image.

someone already makes such a correction tool.
it also corrects lens distortion.
you buy the correction software in modules
for the camera, and for each lens separately.


--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

Lionel wrote:

Kibo informs me that Crownfield stated that:

Chuck Forsberg wrote:

I downloaded a trial version of JSC Paint Shop Pro 9.
It includes a tool for CA. I was expecting a routine
to realign the various colors but it appears instead to
merely be some sort of color filter.

Are all CA tools just color touchups, or do some of them
actually realign the various colors' images?

how do you imagine that the perfectly aligned color images,
coming out of the camera perfectly aligned,

If they were perfectly aligned, there wouldn't be any chromatic
aberration, surely?

and I think you would be incorrect.
the image colors are correctly aligned,
in the center parts of the image,
but probably towards the edge, the color alignment varies
as a function both the color and the distance from center.

're-alignment', better called 'correction'
would be a function of the lens, of the sensor, of the color,
and of the position from the center of the image.

someone already makes such a correction tool.
it also corrects lens distortion.
you buy the correction software in modules
for the camera, and for each lens separately.


--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

"M-M" wrote in message news:nospam-
Can you elaborate on these filters and how they might be obtained?

Here is an example of what I am trying to eliminate. Note the purple
fringe:

http://www.mhmyers.com/temp/fringe.jpg

m-m

That fringe is not chromatic abberation, it's sensor based and is a classic
example of the problems associated with Sony and Kodak sensors when there
are bright (or dull) objects against a dark (or bright) background. Other
sensors will also produce the effect but those two are the worst I've
experienced. Add it to a cheap lens and it doesn't get much worse than that!

You should get a program called CAfree from www.Shaystephens.com It costs
$10 US and is well worth the cost. Unfortunately it need photoshop or
paintshop pro to work but it does indeed work. I found Shay to be on the
ball and easy to communicate with and no... I have no relationship in any
way, shape or form other than to have bought his product to fix one of my
wife's Olympus camera's fringed pictures so I could enlarge it... But that's
another story.

Douglas