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andyone

macrumors member
Original poster
Jan 21, 2008
77
0
I noticed some bad purple/green fringing in LX3 RAW pictures that are converted with Aperture 3. Example (100% crop):
RoTRl.jpg


RAW: http://img.photographyblog.com/...ample_images/panasonic_lumix_dmc_lx3_06.rw2

I don't own the LX3 yet, I used one of the samples from: http://www.photographyblog.com/reviews_panasonic_lumix_dmc_lx3_3.php
There's also a camera-JPEG version of the same motive, and there is much less fringing.

Is this only a problem with the LX3 processing, or is there also no CA correction implemented for other cameras that support it?
 

AndyGordon

macrumors newbie
Oct 24, 2009
28
0
Cambridgeshire, UK
Yup - cleans up nicely in Aperture 3 as well,

I assume you selected the Chromatic Aberration tool and used that? It won't do it automatically I believe
 

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andyone

macrumors member
Original poster
Jan 21, 2008
77
0
If you look at it more closely you will see that this much worse than the result of the in-camera CA correction or the result posted by firestarter. The fringes in the sky are gone, but now there are fringes in the red stone (look at the right edge of the left chimney). I believe that's because the direct RAW CA correction that is done in-camera (and apparently in Lightroom) is aware of the lens properties that are stored in the RAW file, whereas the correction tool in Aperture just operates as an additional "filter".
 

AndyGordon

macrumors newbie
Oct 24, 2009
28
0
Cambridgeshire, UK
This could also be that this was a 5 second tweak with no attempt to maximise quality of the image, just to show that there was a) a CA adjustment tool available in Aperture, and b) that you had to manually select and use it.

I'm sure I could have achieved a better result, but to be fair I have other things to do.

The OP asked about Aperture, so assuming that is the software they have, the fact that LR does something else / better / differently is irrelevant unless they also have that software.

just my tuppence worth
 

andyone

macrumors member
Original poster
Jan 21, 2008
77
0
The point here is that Aperture 3 does not properly process the LX3 RAW file, i.e., in order to achieve a result that matches the quality of the in-camera processing or other raw converters, you need to put in additional, manual work with filters and brushes. That should be an important piece of information for anyone considering purchase of Aperture 3 or the LX3.
 

Westside guy

macrumors 603
Oct 15, 2003
6,403
4,269
The soggy side of the Pacific NW
The point here is that Aperture 3 does not properly process the LX3 RAW file, i.e., in order to achieve a result that matches the quality of the in-camera processing or other raw converters, you need to put in additional, manual work with filters and brushes. That should be an important piece of information for anyone considering purchase of Aperture 3 or the LX3.

I'm surprised that anyone who's considering either Aperture or Lightroom would want the software to do any non-standard RAW processing by default! Why would you go with an expensive and ostensibly professional application and then want it to apply cookie cutter adjustments to all your images?

Chromatic aberration is going to be specific to a limited range of shooting conditions, unless you're using crap glass. The software shouldn't be making assumptions about the presence or absence of CA without the user's intervention. Of COURSE this correction should require "manual work"!
 

wheelhot

macrumors 68020
Nov 23, 2007
2,084
269
definitely agree with westside guy.

And fyi, what you see in your camera is actually the JPEG preview of the RAW file, not the actual RAW file :rolleyes:
 

AndyGordon

macrumors newbie
Oct 24, 2009
28
0
Cambridgeshire, UK
The point here is that Aperture 3 does not properly process the LX3 RAW file, i.e., in order to achieve a result that matches the quality of the in-camera processing or other raw converters, you need to put in additional, manual work with filters and brushes. That should be an important piece of information for anyone considering purchase of Aperture 3 or the LX3.

I assume by properly, you mean based on whatever assumptions the programmers have made?

Personally, I want the base data available to me (Raw) and the appropriate toolset to achieve the result I want, which means that I do not want 'Auto' adjustments - but then I am just an old fashioned photographer who would rather use knowledge and techniques (to the best of my ability) rather than rely on someone else's decisions.

Definitely agree with Westside Guy as well - the day I leave a computer to make all my photographic decisions for me is the day I go back to using P (Professional :) )mode, film and a 1hr processing lab (if they still exist)

Cheers

Andy
 

andyone

macrumors member
Original poster
Jan 21, 2008
77
0
I assume by properly, you mean based on whatever assumptions the programmers have made?

Again you are missing the point. The information about the lens and the sensor and everything is in the RAW file, the software does not have to make any assumptions, no guesswork, just physics and mathematics. And of course, the feature could be easily disabled with a checkbox, if you insist on having the uncorrected image. The guesswork starts when you have a RAW converter like Aperture that discards this information. Then your only choice is a cookie-cutter attempt at CA correction or manual work.
 

AndyGordon

macrumors newbie
Oct 24, 2009
28
0
Cambridgeshire, UK
Hi Andyone - not being picky here, but the OP's original post was specifically about Aperture - and the way Aperture did not appear to correct CA. Whlst yo make valid points on embedded information in the RAW file, this information is still needing to be interpreted by the developer to correct the CA.

Whilst the information is physics etc, the interpretation is human, and lets face it, to err is to be human.

Horses for courses I guess - I prefer a manual approach so that I can see the impact of adjustments on all aspects of the image, I can see that others would prefer it to be done automatically.

Just my tuppence worth
 

Westside guy

macrumors 603
Oct 15, 2003
6,403
4,269
The soggy side of the Pacific NW
Again you are missing the point. The information about the lens and the sensor and everything is in the RAW file, the software does not have to make any assumptions, no guesswork, just physics and mathematics. And of course, the feature could be easily disabled with a checkbox, if you insist on having the uncorrected image. The guesswork starts when you have a RAW converter like Aperture that discards this information. Then your only choice is a cookie-cutter attempt at CA correction or manual work.

Please explain this, because I really don't think it's completely thought through. The RAW file data does not, in fact, include some magic bit that says "this pixel is true data" and "that pixel is due to CA". You cannot just assume that a given lens at a given aperture and/or focal length is going to exhibit CA - it may have certain tendencies, but it's going to be affected by completely external factors as well. I don't think, for example, software should assume "if it's purple and it's between a light area and a dark area then it's CA" because depending on the subject it very well may not be. That's why RAW converters generally don't perform that correction automatically - not in Lightroom, not in Aperture, not in Capture NX. You have to decide to apply the correction.

I believe what you are arguing against is the granularity that the Aperture solution offers. Fair enough, I suppose, but philosophically I prefer it - even if it's more work to fix when an image has a lot of CA issues. It might be frustrating if I had to deal with CA a lot; I just don't know - but I don't want the software to decide "this is CA" and "that isn't CA" on its own. It seems to me the whole point of shooting RAW is to get maximum control over your images. If a quick auto-correction is really what you want, why not just shoot JPEG and let the camera's converter make those decisions? As you pointed out earlier, the in-camera conversion is generally decent - it's probably as good as any software's auto-correction algorithm.
 
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