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Author Topic: dealing with chromatic aberration fringe, etc  (Read 8623 times)

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« on: April 02, 2010, 06:45 »
0
Hi,

i have to deal with fringe and complex chromatic aberrations. Do you have good tutorials / books to recommend on this topic?

I do mostly of the things in Lightroom but when the distortions get nasty you cant fix it in Lightroom anymore. I am not a Photoshop Guru, so any help would be greatly appreciated.

Regards, Alex


« Reply #1 on: April 02, 2010, 07:00 »
0
Two choices: Get Photoshop

or

If you have Canon cameras and lenses you can correct these issues with one click in the software provided with the camera. Shoot everything RAW then use Digital Photo Professional. I love it for speed and accuracy. Even better than photoshop.

Good luck,
-Larry

« Reply #2 on: April 02, 2010, 07:47 »
0
Hi,

i have to deal with fringe and complex chromatic aberrations. Do you have good tutorials / books to recommend on this topic?

I do mostly of the things in Lightroom but when the distortions get nasty you cant fix it in Lightroom anymore. I am not a Photoshop Guru, so any help would be greatly appreciated.

Regards, Alex

Alternative you can invest in prime lenses = less or no chromatic aberation.

Patrick.

« Reply #3 on: April 02, 2010, 08:23 »
0
i have to deal with fringe and complex chromatic aberrations. Do you have good tutorials / books to recommend on this topic?

Like someone already said: Invest in some quality (prime?) glass. If you are at least half-serious about your stock photography it's much better to be shooting than sitting at computer pixel-peeping just because the glass is sub-par.

If you shoot with a Canon, buy only Canon's lenses and convert your raw files with DPP (Digital Photo Professional), you can remove much of the problems with a couple of mouse clicks because there are "profiles" for each lens (with a few expectations). I think at least my 5D mk II can also do the processing in-camera if I shot JPG (which I don't).

(The above may also apply in some way for other brands)

The amount of time I spend pixel-peeping have gone down drastically. My "secrets":
-I shoot raw. I also use grey cards for white balance whenever possible.
-Canon 5D mk II produces clean images. I almost usuallty shoot at 100 ISO
-I try to get the correct exposure with good contrast and look at my histograms (no clipping at any channel yet not too flat contrast)
-I use DPP for raw processing, it does the lens corrections and produces good results even if it's a bit cumbersome to use.
-I try to keep my sensor reasonably clean.
-I use quality glass. It doesn't even have to cost that much, there are some "bargains"
-I avoid extreme apertures, most of my images are shot between 4 and 11
-I calibrate my screen with a hardware calibrator
-I have set my sharpening in DPP on level 3, I usually don't sharpen my images after that (that would just boost the artefacts)
-If I'm doubtful for some image's sharpness or noise I may downsize the image as far as 50% (that's about 5mpix from a 5DmkII file, enough for most micros)
« Last Edit: April 02, 2010, 08:37 by Perry »

« Reply #4 on: April 02, 2010, 08:23 »
0
Hi,

i have to deal with fringe and complex chromatic aberrations. Do you have good tutorials / books to recommend on this topic?

I do mostly of the things in Lightroom but when the distortions get nasty you cant fix it in Lightroom anymore. I am not a Photoshop Guru, so any help would be greatly appreciated.

Regards, Alex

Alternative you can invest in prime lenses = less or no chromatic aberation.

Patrick.

Digital Photo Professional also corrects the pincushion and barrel distortion of Canon prime and zoom lenses. I forgot this: It corrects for peripheral light fall off also. (Again with one click)
With prime lenses and DPP you have the best of both.

-Larry

« Reply #5 on: April 02, 2010, 08:54 »
0
Not an expert in these situations. Don't get too many .. as I only shoot with primes.
But I notice that fringes are prominent in high contrast situations... ie. bright background, dark clothes, ... bright summer or noon day sun with framing ,etc..
you can more or less be conscious about this, and use a reflector to reduce the extreme contrast
or use  fill flash.
If not, you can use Replace Color and Layers to reduce saturation and "cheat" your way around this problem.
It might not always work , esp if you need 48MB for Alamy, or upload the larger sizes . But last alternative , you can downsize and submit. small enough that the fringe is not visible, except to the bionic IS and DT reviewer who has xray eyes that sees 100% images like 400% ,lol.
then, I would throw in the towel... lmao
« Last Edit: April 02, 2010, 08:56 by PERSEUS »

« Reply #6 on: April 02, 2010, 22:49 »
0
i have to deal with fringe and complex chromatic aberrations. Do you have good tutorials / books to recommend on this topic?



If you shoot with a Canon, buy only Canon's lenses and convert your raw files with DPP (Digital Photo Professional), you can remove much of the problems with a couple of mouse clicks because there are "profiles" for each lens (with a few expectations). I think at least my 5D mk II can also do the processing in-camera if I shot JPG (which I don't).

-Canon 5D mk II produces clean images. I almost usuallty shoot at 100 ISO

-If I'm doubtful for some image's sharpness or noise I may downsize the image as far as 50% (that's about 5mpix from a 5DmkII file, enough for most micros)

One of the reasons I bought the  mk II.... and I use ONLY Canon glass.
Yet... low and behold,  I'm out shooting in the snow on a bright sunny day,  dark, dark blue skies......... and whoaaaaaaaa     purple fringing all over the place in jpgs. Snow against the sky, snow against shadows...  So bad, I could spend a month on one image and not eliminate it all..   I suppose I gotta shoot at lower ISO's....
wasted a lot of good time with those shots.  I'm all about getting the best image I can out of the cam... used to be, I'd shoot crap and fix it later...  Not now... just don't have the time.
   Besides ISO... what other reasons may be giving me purple fringe in the  mk II?    8)=tom

« Reply #7 on: April 02, 2010, 23:17 »
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Some fringing is not chromatic aberration. In PS (or Camera Raw) there are sliders for fixing CA, both Red/Cyan and Blue/Yellow. However there's also a dropdown labelled DeFringe, which I believe addresses a different type of fringing. Most sensors interpolate pixels as any one photosite is either R, G or B (Bayer grid), and sometimes the software interpolates incorrectly producing fringing (or I think that's the reason). I've also heard of sensor overload in bright areas affecting nearby dark areas. Anyway, it's not caused by the lens. The defringe options in CR may fix it, but I usually find I have to do some manual work to get rid of it. Desaturating the colour often works, or else cloning along the edge.

« Reply #8 on: April 03, 2010, 00:14 »
0
The fast and easy way to eliminate fringing with Photoshop is to create a new layer, change it's mode to 'Color', then paint over the necessary areas using a suitable color. Give it a try, you'll be surprised by how well it works!
« Last Edit: April 03, 2010, 00:55 by sharply_done »

« Reply #9 on: April 03, 2010, 01:04 »
0
...
Yet... low and behold,  I'm out shooting in the snow on a bright sunny day,  dark, dark blue skies......... and whoaaaaaaaa     purple fringing all over the place in jpgs. Snow against the sky, snow against shadows...  So bad, I could spend a month on one image and not eliminate it all..   I suppose I gotta shoot at lower ISO's....

Sometimes you just can't avoid fringing, no matter how good your lenses are and how well you know your camera. Shooting with snow and bright sun can be particularly troublesome. Give the above technique a try - it won't take very long to fix even the most fringiest of shots. Not a month, anyway! (grin)
« Last Edit: April 03, 2010, 01:07 by sharply_done »

« Reply #10 on: April 03, 2010, 01:23 »
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One of the reasons I bought the  mk II.... and I use ONLY Canon glass.
As Larry said, use the Digital Photo Professional that comes with the cam, and that corrects CA in the RAW. If you use Canon lenses, it will address the CA and vignetting even automatically.

« Reply #11 on: April 03, 2010, 03:57 »
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Try what Sharply suggested you to do. Did you try to google for it?

« Reply #12 on: April 03, 2010, 05:38 »
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One of the reasons I bought the  mk II.... and I use ONLY Canon glass.
Yet... low and behold,  I'm out shooting in the snow on a bright sunny day,  dark, dark blue skies......... and whoaaaaaaaa     purple fringing all over the place in jpgs.

What lens are you using?
Try to do as I said, shoot raw and process with DPP and remember to do the necessary clicks on the NR/Lens/AO page ("Lens aberration correction / Tune")

microstockphoto.co.uk

« Reply #13 on: April 03, 2010, 15:57 »
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investing in good lenses as many suggested is the best option of course

but - for already taken pictures - when the purple fringe is actually "purple" the easiest solution is to desaturate the "magenta" channel; or - more elegantly - adjusting hue on the magenta channel instead of just desaturating

sometimes unfortunately fringe is rather more bluish than purple; and since blue - unlike magenta - is usually also present in other parts of the picture (sky) it's more difficult to remove
« Last Edit: April 03, 2010, 16:01 by microstockphoto.co.uk »

« Reply #14 on: April 03, 2010, 16:12 »
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I like 'barts pf fixer' which is a free photoshop action. Does a better job than the straight desaturate.

agree also about lens choice photozone.de reviews tell you how much pf / ca you can expect. 

« Reply #15 on: April 05, 2010, 15:22 »
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Thank you all for your comments!

I am not a pro photographer and not a megaselling microstock superstar so i do not have the money for a fullframe camera with prime lenses.
I do have a D200 with some Nikon and some Sigma lenses which i can control relatively good in pp and i am not asking for.
The camera which causes theese issues (if you are interested) is the Olympus Pen. I bought it with the 20mm 1,7 lens from Panasonic as the ultimative quality compact which i have with me all the time when i leave the house.
In fact it is a great camera with wonderful color and great contrast being tack sharp with the 20mm lens.

Does anybody have a link for this pf fixer?
Regards, Alex

« Reply #16 on: April 05, 2010, 16:21 »
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to all....   thanks much for the tips!!!    I'll be trying them out.  8)=tom

« Reply #17 on: April 05, 2010, 16:40 »
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Either you do your expensive lenses buying, either you do your photoshoping, either you go on PRO RAW processing.

You can buy PHASE ONE Capture One 5 and forget about many things regarding CA, model skins and so on...
Also, You can buy DXO Optics Pro 6 and forget on all distorsions and CA which makes your lens ;-)

I have second one and it works nicely with some tweaks expected in future versions...

Cheers!

« Reply #18 on: April 05, 2010, 17:39 »
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The fast and easy way to eliminate fringing with Photoshop is to create a new layer, change it's mode to 'Color', then paint over the necessary areas using a suitable color. Give it a try, you'll be surprised by how well it works!

now why didnt i think of that??? awesome tip

lisafx

« Reply #19 on: April 05, 2010, 17:51 »
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Even with good lenses you will sometimes get fringing.  I only use L lenses on my 5DII and still get some fringing in some situations.  Particularly shooting full body people over white. 

I have found that the chromatic aberration sliders in LR fix it in 95% of cases.  In the rare situation where it doesn't solve the problem I usually just select the color with the dropper in Photoshop and then "paint" the color over the edges.  Kind of a pain, but sometimes quicker than playing with the sliders.

I will look for that "Defringing" drop down Avril suggests.  I never knew that existed.

« Reply #20 on: April 06, 2010, 03:37 »
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I do have a D200 with some Nikon and some Sigma lenses which i can control relatively good in pp and i am not asking for.
I shot with a D200 and a Sigma lens till October 2009. The CA reduction in the RAW works fine in Photoshop, but you have to manipulate the slider manually.

« Reply #21 on: April 09, 2010, 15:58 »
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I thought with Lightroom one can do pro raw processing...

I am trying Capture One 5 right now and its a hell of a raw editor! No problem with chromatic aberration (and auto corrected) and a great interface (very similar to Lightroom). The only downside is that it is very slow on my macbook but i can still work with it (at least its much faster than Olympus Master 2).

Thank you for this great hint,

Regards, Alex

Either you do your expensive lenses buying, either you do your photoshoping, either you go on PRO RAW processing.

You can buy PHASE ONE Capture One 5 and forget about many things regarding CA, model skins and so on...
Also, You can buy DXO Optics Pro 6 and forget on all distorsions and CA which makes your lens ;-)

I have second one and it works nicely with some tweaks expected in future versions...

Cheers!


 

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