Posted by Danny Laureys on February 28, 2010 at 4:10 AM
Hi,
When I looked at a larger picture of "Sunset at Lone Pine" I noticed Fringing? on right side on the faraway peaks. any suggestions how to preveny this and way this happened. Thank you for your time.
Posted by Danny Laureys on February 28, 2010 at 4:15 AM
You can also see a larger version where it is more noticable at www.flickr.com/photos/dlaureys this is a 2 file merge. also there in raw file.
Posted by Rodney Ninow on February 28, 2010 at 12:29 PM
I am not sure exactly what it is called, but I have seen it where very bright light intersects darker areas, like you have with the peaks and the setting sun behind them here. I don't know how to prevent it, other than to avoid shooting digital in those situations. I may or may not show up in a print.
I have seen this happen in the conditions that Rodney describes. When you have an edge that is not smooth, like a ridge line, a diffraction effect can ocurr. This is natural, and little or nothing can be done about it. The effect could be exacerbated by the lens design and/or the quality of the glass and/or coating, or sharpening in post processing.
--P
Posted by Danny Laureys on February 28, 2010 at 1:55 PM
Thanks for the reply, this was shot with a Canon 70-200L lens, I'll try to shoot another sunset loke this one and see if this will happen again. Thanks again
Posted by Richard Wong on February 28, 2010 at 6:36 PM
Chromatic aberration happens on every lens to varying degrees. With a good quality lens like the 70-200 you can probably fix it when processing the RAW file. Lesser quality lens are more difficult to deal with.
Posted by Tony Siciliano on February 28, 2010 at 8:39 PM
If you use Photoshop CS4, you can fix this (to varying degrees, sometimes quite successfully, sometimes less so), in either Camera Raw or in Photoshop. In Camera Raw you click the 6th icon (looks like a lens) on the top of the menu bar on the right. If you open the photo into Photoshop, the fix is under Filter/Distort/Lens Correction. I'm not 100% sure, but I think the Lens Correction will not work in 16 bit mode; if so, just convert to 8 bit mode. The fix is easy....you just magnify the photo to 200% or so and just start trying out the sliders. Feel free to email me to ask for more info if you are interested.
Posted by Eric Good on February 28, 2010 at 11:24 PM
Yep that area of the image it is not uncommon to see some fringing. If you can't eliminate in the Raw editor, I find simply desaturating the particular color in the problematic areas and using a masking layer can be a solution as well. Nice image by the way!
Posted by Danny Laureys on February 28, 2010 at 11:28 PM
Thanks Richard, Tony, I'm waiting on my new computer and also ordered PSCS4, I'll try to fix it when I have my equipment. Thanks again.
Danny, I looked at your flicr site and the image looks to be the same size there as here at CANP. With that said, I'm not seeing the issue at this size. However, the term you are using I fully understand and can imagine what is being seen at close-up inspection of the image.
You might read this article from OP Magazine I recall from awhile back now to see if it offers any ideas. Defringing Article
Although, it is based upon composites, it might stir some ideas up anyway.
Posted by Steve Sieren on March 1, 2010 at 11:04 AM
Danny, Someone just asked me this so sorry about this canny response.
Fringing is best caught in the RAW developing of a file. It's even better caught before you do any RAW editing. Any adjustments will enhance it even just contrast. Especially if you use the recovery tool too much, that seems to bring out the most fringing and the fill tool . With most Canon L lenses all you do is slide the Chromatic Abberation red / cyan to the left or into the negative just slightly. All lenses have a specific adjustment necessary. If you are compositing make sure you adjust this in all files for your composite because pixels will shift and not line up exactly the way they used to. Anyway it's best to make this a habit, it's harder to fix after the fact.
Fringing has been around so we will see an article on the subject every year until it's gone from our capture and then we'll have to replace our lenses.
I am not sure if chromatic abberation caused by the lens is the culprit here. When light passes over an edge or thru a slit, diffraction will occur when certain conditions are met. If chromatic abberation was the problem, it would be visible in other off-axis areas of the image. If the fringing is localized to the very bright area of the image, diffraction is the likely cause.
I have an image of Mt. Tom with a very bright full moon setting behind it. After scanning I noticed what appeared to be a white line (it looked like a sharpening halo) at the ridge line. Since this was a raw unsharpened scan, and the lens was Mamiya 210mm on 645 film (this lens is very sharp and well corrected) I then looked at the actual transparency with a high-power loupe; the line is in the image. I couldn't figure out what was causing it. After thinking about it fo a spell, the only thing that could have caused this was diffraction. It was quite an odd occurence. It was in thinking about this particular image that gave me the idea that this is what [i]may]/i] be hapening in Danny's shot.
Hopefully, the fringing can be at least partially controlled in the RAW editor, or in post processing.
Steve: abberations cannot be completely eliminated even with the best lens design, glass and coatings; it's the nature of the beast that fringing must occur when light passes through curved surfaces. So, you won't need to replace your glass anytime soon.
Discussion
12 repliesWhen I looked at a larger picture of "Sunset at Lone Pine" I noticed Fringing? on right side on the faraway peaks. any suggestions how to preveny this and way this happened. Thank you for your time.
--P
You might read this article from OP Magazine I recall from awhile back now to see if it offers any ideas.
Defringing Article
Although, it is based upon composites, it might stir some ideas up anyway.
Fringing is best caught in the RAW developing of a file. It's even better caught before you do any RAW editing. Any adjustments will enhance it even just contrast. Especially if you use the recovery tool too much, that seems to bring out the most fringing and the fill tool . With most Canon L lenses all you do is slide the Chromatic Abberation red / cyan to the left or into the negative just slightly. All lenses have a specific adjustment necessary. If you are compositing make sure you adjust this in all files for your composite because pixels will shift and not line up exactly the way they used to. Anyway it's best to make this a habit, it's harder to fix after the fact.
Fringing has been around so we will see an article on the subject every year until it's gone from our capture and then we'll have to replace our lenses.
I have an image of Mt. Tom with a very bright full moon setting behind it. After scanning I noticed what appeared to be a white line (it looked like a sharpening halo) at the ridge line. Since this was a raw unsharpened scan, and the lens was Mamiya 210mm on 645 film (this lens is very sharp and well corrected) I then looked at the actual transparency with a high-power loupe; the line is in the image. I couldn't figure out what was causing it. After thinking about it fo a spell, the only thing that could have caused this was diffraction. It was quite an odd occurence. It was in thinking about this particular image that gave me the idea that this is what [i]may]/i] be hapening in Danny's shot.
Hopefully, the fringing can be at least partially controlled in the RAW editor, or in post processing.
Steve: abberations cannot be completely eliminated even with the best lens design, glass and coatings; it's the nature of the beast that fringing must occur when light passes through curved surfaces. So, you won't need to replace your glass anytime soon.
--P