Fringing and chromtic aberration etc

[Thornton]

I have a Canon zoom which has quite bad (fringing or chromatic aberration?- not sure which: I'm confused) at the wide end: purple on one edge and green on the other. If I use the DLO feature of Canon DPP, it makes a very good job of removing it. However, for a particular conversion I'm working on, PSE seems better for my purposes (using two exposures but not using an HDR tool). But I don't know how to remove this fringing (CA?) in Elements. The best solution I've come up with is to convert the raw in PSE, then open the 8 bit TIFF in Affinity Photo, which did allow me to remove all the purple fringing and most of the green, at least down to acceptable levels.

BTW, it wasn't a great problem having to use Affinity for this correction, because the Blend Ranges feature seemed to allow me easily to just use the non-blown highlights from the darker exposure to replace the blown highlights in the lighter exposure. I wonder if I could have achieved this more efficiently just in PSE? I did try masking to replace the highlights, but wasn't happy with my efforts.

[Shadowman]

One method I found online.

https://binged.it/2HzgD30

[Thornton]

Thank you, John. I’ll give this procedure a try.

T

(p.s. just edited my spelling of chromatic in the title: I’m due an eyetest next month, not before time. Maybe I should give up photo editing until after it. I think I’ll be having new specs this time!)

[Shadowman]

Thank you, John. I’ll give this procedure a try.

T

(p.s. just edited my spelling of chromatic in the title: I’m due an eyetest next month, not before time. Maybe I should give up photo editing until after it. I think I’ll be having new specs this time!)

Usually spell check catches that.

[shreds]

Fringing (often called purple fringing) and chromatic abberation, are not uncommon on many lenses, (often a corrolation to cost, although you can pay thousands and still get CA or fringing). It is often exacerbated by the arrangement of the glass inside the lens. Some lens coatings also are designed to cut down on the amount of CA and fringing occurring.

Such unfortunate effects are usually most noticeable when shooting into the light and it is the stray light bouncing around in your lens that make such matters more visible, so be aware of that when out shooting. Easier to try and minimise at point of capture than later in software.

[Thornton]

Fringing (often called purple fringing) and chromatic abberation, are not uncommon on many lenses, (often a corrolation to cost, although you can pay thousands and still get CA or fringing). It is often exacerbated by the arrangement of the glass inside the lens. Some lens coatings also are designed to cut down on the amount of CA and fringing occurring.

Such unfortunate effects are usually most noticeable when shooting into the light and it is the stray light bouncing around in your lens that make such matters more visible, so be aware of that when out shooting. Easier to try and minimise at point of capture than later in software.

Thanks. I was somewhat confused by the terminology, and still am to an extent, because the terms seem to be used both as if they refer to different phenomena, and as if they are interchangeable. However, it all seems to boil down, on a practical level, to having unwanted coloured fringes along (mostly) high contrast edges. In the case of my Canon 17-85 zoom, it is certainly worst towards the corners, worst of all at the widest zooms, even at smaller apertures, and the purple is most noticeable. I was really looking for an easy way to remove it using PSE, but the stripped-down version of Camera Raw which comes with it, lacks the tools. So my choices were DPP, which does the job excellently, or Affinity Photo. However, since I wanted to use the raws directly in Affinity for HDR merging, I couldn’t take advantage of DPP. In fact, experimenting with Affinity, I have now found that the CA removal tool in the raw development part of the program, also did a good job, much easier than messing about with the defringing filter later in the workflow in Affinity. I think that when I get more confident with this program I’ll be using PSE less and less.

T

[DanK]

Julian,

Purple and green fringing is a type of chromatic aberration, lateral CA. There is a good explanation of CA toward the bottom of one of the tutorials on this site, https://www.cambridgeincolour.com/tu...orrections.htm.

Dan

[shreds]

……. In fact, experimenting with Affinity, I have now found that the CA removal tool in the raw development part of the program, also did a good job, much easier than messing about with the defringing filter later in the workflow in Affinity. I think that when I get more confident with this program I’ll be using PSE less and less.
T

For those who have not used PS CS or PSE before, I will say that Affinity does make learning easy and is more intuitive with good online help built in. Despite being a long time user of PS, I did download Affinity to see how it compared and was pleasantly surprised.

(I have looked at most softwares over the years in the photographic arena, and whilst Phase One/Camera One software was at one point superior to PS, it is quite involved and I wouldn't suggest it to anyone without some experience in softwares already).

It also depends on which platform you use, (Apple/MS/Linux etc) although this is less of an issue nowadays, unless you want to grapple with free software, which is perhaps more for those computer minded individuals?

[Marwus]

I am using Rawtherapee, there is in build tool for this case. I have same issue with my 75-300 canon DC iii lens, on 300 it suffers a lot from chromatic aberation. But very often is Rawtherapee able to remove it.

[xpatUSA]

I am using Rawtherapee, there is an in-built tool for this case. I have the same issue with my 75-300 canon DC iii lens, on 300 it suffers a lot from chromatic aberration. But very often Rawtherapee is able to remove it.

There's more information about that here:

http://rawpedia.rawtherapee.com/Lens...ens_Correction

and here:

http://rawpedia.rawtherapee.com/How_...d_DCP_profiles

Hope this help those unfamiliar with RT.

P.S. I followed the second link and went looking on my computer and found a ton of Adobe .lcp profiles. Once you know where they are, RT can use them!

[Tronhard]

Hi Julian:

As regards the 75-300... Everything I have read indicates that this is arguably the worst lens that Canon have produced for image sharpness and resolution. I had one that I inherited with a kit about 15 years ago (and I realize there have been several iterations of the lens since then), so I would be interested in your views as a user of the MKIII version.

I have personally always preferred to have the image as close to right in the camera as opposed to correcting in PP, so I sold the 75-300 and opted for the Canon EF 70-300mm f/4-5.6 IS USM, of which there are two variants: the MkI issued in 2005 and the MkII in 2016. If you want to see my review of these two units see my post: Canon Non-L 70-300 Canon Lenses

[Thornton]

Hi Julian:

As regards the 75-300... Everything I have read indicates that this is arguably the worst lens that Canon have produced for image sharpness and resolution. I had one that I inherited with a kit about 15 years ago (and I realize there have been several iterations of the lens since then), so I would be interested in your views as a user of the MKIII version.

I have personally always preferred to have the image as close to right in the camera as opposed to correcting in PP, so I sold the 75-300 and opted for the Canon EF 70-300mm f/4-5.6 IS USM, of which there are two variants: the MkI issued in 2005 and the MkII in 2016. If you want to see my review of these two units see my post: Canon Non-L 70-300 Canon Lenses

Hi Trev,
The zoom lens I had in mind when I originally posted this was the Canon EF-S 17-85, which was supplied with my slr some years ago, but which I am still using with my Canon 70D. The fringeing is only really noticeable at the widest end but I can deal with it now, either in DPP or Affinity. It was Marwus whose post here mentions the 75-300 lens. In fact I have the first version of the non-L 70-300 you mention, and have been quite satisfied overall with the shots I’ve got with it. (This also came in the same slr package as the 17-85).

Julian

[GuyPhoto]

I think the consensus is pretty clear; one can't just rely on Adobe CR/Lightroom or whatever app you are using for post if you want really clean files. Third party RAW processing is the "next level" in getting consistently fine results. Robin at Lightweight Photographer has tried many combinations of camera and raw processor, and especially if you are using a non Socanikon camera, has concluded that a third party processor might be a better fit. I find Iridient Developer (quick learning curve) and DXO to be better optimized for particular cameras. DXO profiles and tests every camera via their labs, and the guy who created Iridient has very carefully tailored the processing to particular files. The improvements I have seen using them with my Olympus have pleased me.

[DanK]

if you are using a non Socanikon camera, has concluded that a third party processor might be a better fit.

the OP shoots Canon.

I think the consensus is pretty clear; one can't just rely on Adobe CR/Lightroom or whatever app you are using for post if you want really clean files.

That's certainly not the consensus among the photographers I know, and I use Lightroom myself for raw processing. but I would be interested in learning more. Do you have a link to an article describing the Lightweight Photography tests?

[Manfred M]

I think the consensus is pretty clear; one can't just rely on Adobe CR/Lightroom or whatever app you are using for post if you want really clean files. Third party RAW processing is the "next level" in getting consistently fine results. Robin at Lightweight Photographer has tried many combinations of camera and raw processor, and especially if you are using a non Socanikon camera, has concluded that a third party processor might be a better fit. I find Iridient Developer (quick learning curve) and DXO to be better optimized for particular cameras. DXO profiles and tests every camera via their labs, and the guy who created Iridient has very carefully tailored the processing to particular files. The improvements I have seen using them with my Olympus have pleased me.

I'm going to have to disagree with you to a point. There is no consensus as to the "best" raw converter and everyone has their own personal favourite(s). I regularly use three different ones and they all have their strengths and weaknesses; Adobe Camera Raw, Phase One Capture One and DxO PhotoLab. The reason for my using one versus another at a specific time has a lot to do with what / how I am shooting, the quality of the raw data I am working with and the best fit with my workflow.

I very much use a "minimalist" approach with my raw converters; doing little other than the actual raw conversion, lens correction and noise reduction / input sharpening. All of my edits are done in Photoshop.

- Camera Raw is my "go to" raw converter, mostly because it supports SmartObjects and integrates so well with Photoshop. I use a non-destructive workflow, so SmartObjects are something I use as much as possible.

- I use DxO PhotoLab with "problem files"; high noise, issues where I want the more aggressive lens correction algorithms, etc. It is the one raw converter that I use that does not support custom camera ICC or DCP profiles.

- I use Capture One when shooting tethered and doing initial file prep during the shoot. It now supports custom camera (DCP) profiles. This functionality is quite recent.

That being said, I'm quite willing to bet that no one can tell which raw converter I used on any images.