scho Posted March 12, 2007 Share #1 Posted March 12, 2007 Advertisement (gone after registration) Thanks to Don (x-ray) over at RFF, who noticed what appeared to be some slight greenish/cyan fringing along the edges of some tree branches in one of my M8 images. He thought at first it might be CA, but after some testing I found that it was a problem in the way Lightroom processed the raw file. It was impossible to remove the artifact using the red/cyan or blue/yellow CA sliders, but what did work was simply turning off color noise reduction in the detail tab (I had usually just left this at the default 25 setting). So, if you see what appears to be CA in any of your Lightroom processed M8 images try adjusting the color noise reduction setting. Two images below illustrate the problem, look at upper left and right corners of the full size original images: Default color noise reduction 25: http://www.pbase.com/scho/image/75458092/original Color noise reduction off: http://www.pbase.com/scho/image/75533276/original Pbase has been exhibiting slow performance recently, so be patient if these large images don't load quickly. Link to post Share on other sites More sharing options...
Advertisement Posted March 12, 2007 Posted March 12, 2007 Hi scho, Take a look here Lightroom - faux CA in M8 images. I'm sure you'll find what you were looking for!
Guest sirvine Posted March 12, 2007 Share #2 Posted March 12, 2007 I never use any noise reduction when developing from the M8. I think it robs this camera of its greatest strength. Link to post Share on other sites More sharing options...
scho Posted March 12, 2007 Author Share #3 Posted March 12, 2007 I never use any noise reduction when developing from the M8. I think it robs this camera of its greatest strength. I never use luminance noise reduction, but until this incident always thought that the default color noise reduction wasn't a problem. Now they are both set to zero when processing M8 files. By the way, this problem is specific to Lightroom 1.0 and ACR in CS2 or CS3. Doesn't occur in C1, but I don't like C1 processing. Link to post Share on other sites More sharing options...
mike prevette Posted March 12, 2007 Share #4 Posted March 12, 2007 I've found the color nise reduction to be the most destructive ting in Lightroom. On low iso shots it throws a ton of detail out the door. _mike Link to post Share on other sites More sharing options...
cboudier Posted March 13, 2007 Share #5 Posted March 13, 2007 Thanks Carl, very interesting and not only for M8 ! (I encountered the same problem with Pentax DSLR...) Link to post Share on other sites More sharing options...
Englander Posted March 13, 2007 Share #6 Posted March 13, 2007 Although a lot of us think of RAW processors the same as we think of word processors--that all processors do the same thing--there is a (huge) difference between the results rendered by RawDeveloper, ACR, Bibble, C1, Aperture, Lightzone, and Silky, just to name the ones I've looked at. These RAW developers are as different as D76, Rodinal and Microphene. There are not only differences in sharpness, edge acuity, internal contrast, but also in color rendering even when no user adjustments are applied! Lots of supposed CA is actually software rendered and dependent not only on the amount of sharpening/NR applied by the operator, but also in the amount that is applied without the operator's "permission." Some software allows modification of what is done to an image on import before normal user adjustments, and some doesn't. My impression of LR/ACR is that it is a D76 that renders generally acceptable images across a wide range but can be easily surpassed if you are willing to use specific developers for specific situations. The nice thing about digital is you can apply a different developer to each image without applying it to an entire roll AND that you can redevelop if you don't like the results. Carl, the fact that "CA" occurs in one software and not the other, that it is in LR but not C1, indicates you might find something like Raw Developer a more interesting application. For me, it has produced the sharpest images with the least "CA;" but it does not have the auto features of more expensive software. I think its fidelity is much higher than LightRoom/ACR. And it offers several different kinds of sharpening so you can really tailor your results. Joe Link to post Share on other sites More sharing options...
scho Posted March 13, 2007 Author Share #7 Posted March 13, 2007 Advertisement (gone after registration) Although a lot of us think of RAW processors the same as we think of word processors--that all processors do the same thing--there is a (huge) difference between the results rendered by RawDeveloper, ACR, Bibble, C1, Aperture, Lightzone, and Silky, just to name the ones I've looked at. These RAW developers are as different as D76, Rodinal and Microphene. There are not only differences in sharpness, edge acuity, internal contrast, but also in color rendering even when no user adjustments are applied! Lots of supposed CA is actually software rendered and dependent not only on the amount of sharpening/NR applied by the operator, but also in the amount that is applied without the operator's "permission." Some software allows modification of what is done to an image on import before normal user adjustments, and some doesn't. My impression of LR/ACR is that it is a D76 that renders generally acceptable images across a wide range but can be easily surpassed if you are willing to use specific developers for specific situations. The nice thing about digital is you can apply a different developer to each image without applying it to an entire roll AND that you can redevelop if you don't like the results. Carl, the fact that "CA" occurs in one software and not the other, that it is in LR but not C1, indicates you might find something like Raw Developer a more interesting application. For me, it has produced the sharpest images with the least "CA;" but it does not have the auto features of more expensive software. I think its fidelity is much higher than LightRoom/ACR. And it offers several different kinds of sharpening so you can really tailor your results. Joe Thanks Joe. Yes, I agree with your comments about differing results form the various raw converters. I have raw developer and like some of the features, but I prefer the workflow of Lightroom and tight integration with CS3. Old habit I guess, but I still do all of my sharpening post raw devlopment in CS3 using the Photokit Sharpener plug-in (capture and output sharpening). I prefer doing the output sharpening as the last step before printing, after I've decided on the final print size. Carl Link to post Share on other sites More sharing options...
rosuna Posted March 13, 2007 Share #8 Posted March 13, 2007 I've found the color nise reduction to be the most destructive ting in Lightroom. On low iso shots it throws a ton of detail out the door. _mike That's strange. Color noise doesn't affect detail. Link to post Share on other sites More sharing options...
Englander Posted March 13, 2007 Share #9 Posted March 13, 2007 Carl, To clarify a little, I am specifically pointing to sharpening that occurs in raw development. Even when you turn the sharpen off in ACR or LR, you are still getting sharpening and its main artifact is the fringing. With ACR you do not have the option to really get a totally unsharpened image; it is sharpened as the data is converted to an image. With Aperture, you have the option of changing and possibly eliminating that unasked-for feature. I think you can do the same in RD, but I'd have to go back and look. So, I am not talking about the application of pixel pushing as done in CS, there is a whole order of sharpening that has a huge--in my opinion--effect on the overall appearance of your image that you typically can only control by changing raw developers. It may sound like I spend my time pixel-peeping, but I was drawn to look at the differences in developers because I could see differences in the overall impact of 11x17 prints created with different developers. If you want to use a developer that causes some effects you do not like but whose overall software performance you prefer, that is an informed decision that takes into account certain compromises. Go for it. Unfortunately, there are a lot of people who make a decision to work with a developer without your knowledge and then wonder why their images look the way they do. Joe Link to post Share on other sites More sharing options...
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