I'm getting some really bad Chromatic aberration with a fairly new 85mm 1.8.
1) Are you (owners of this lens) seeing similar problems (high contrast areas) with the lens - purple fringing, etc.
2) How can I correct this photo without desaturating the edges that are bad? Editing in LR2, but the Chromatic Aberration (Red/Cyan & blue/yellow) sliders make hardy any improvement to the photo. (I have several other photos from the shoot with the same problem)
Shot on 5D Mark II at f1.8 (RAW)
I'm aware this lens has problems with CA at times, but this seems extreme. Is there something else going on here?
I dont have the 85 1.8, but large aperture lens is fairly susceptible to purple fringing with strong back light. Usually the way to cure is to stop down the lens ( which you wont want to be doing now)
As for the full-size photo goes, the purple fringing is not all that disturbing.
That's not really CA, but it's 'purple fringing' (sorry I don't recall the technical name). LCA gives you the red/cyan or blue/yellow effect and the sliders will fix it. Purple fringe is another issue and AFAIK the way to fix it is to select the purple and desaturate the color until the effect isn't objectionable. I owned the EF100/2 and it has the same problem with high contrast areas.
CVickery wrote:
That's not really CA, but it's 'purple fringing' (sorry I don't recall the technical name). LCA gives you the red/cyan or blue/yellow effect and the sliders will fix it. Purple fringe is another issue and AFAIK the way to fix it is to select the purple and desaturate the color until the effect isn't objectionable. I owned the EF100/2 and it has the same problem with high contrast areas.
IIRC, Purple fringing is one kind of CA I suppose? Its just because purple has a short wavelength, which exaggerate the CA problem much more than other colors.
I think Photoshop has a lens correction feature to fix CA to a limited extent.
If you are using ACR, just go to lens correction tab and then use the Defringe command (all edges setting). That will fix most of it ... then you can selectively remove anything missed.
I have a similar issue with my 35 1.4L, although minor.
In Lightroom, go to HSL / Saturation, select 1:1 scale for your image, and use the "Adjust saturation by dragging in the photo" (little circle in the left top corner of the HSL control).
Select the color you want to desaturate in the image (the purple in this case), and move the mouse up and down to change the saturation of just that specific color.
I don't think any lense should look that way at all. If it is possible, attempt to use this lens on another body to rule out your camera. I would suggest ISO 200 or so just to minimize the sensor blooming. If the problem persists, you definitely need your lens looked at. If it is in warranty, show Canon your unedited RAW file so they can see it for themselves. The camera comes in a relatively hefty price so one expects quality, surely better than a regular consumer camera.
Also, try going to a camera store with your body and use the exact same model lens and take a shot of another contrasty subject matter. See if this is consistent. Then use another model lense, such as the 24-105L set at 85mm with similar settings as this sample shot and see if the problem persists.
Just so you know, I've seen too many lenses out of the factory that need to be calibrated.
Good luck!
P.S. The only time I ever resorted to PS lens correction for CA was the last time. The lens needed fixing and that was that. PS is great, but I try to get as clean an image at capture to reduce post-production.
Phoveo wrote:
I don't think any lense should look that way at all. If it is possible, attempt to use this lens on another body to rule out your camera. I would suggest ISO 200 or so just to minimize the sensor blooming. If the problem persists, you definitely need your lens looked at. If it is in warranty, show Canon your unedited RAW file so they can see it for themselves. The camera comes in a relatively hefty price so one expects quality, surely better than a regular consumer camera.
Also, try going to a camera store with your body and use the exact same model lens and take a shot of another contrasty subject matter. See if this is consistent. Then use another model lense, such as the 24-105L set at 85mm with similar settings as this sample shot and see if the problem persists.
Just so you know, I've seen too many lenses out of the factory that need to be calibrated.
Good luck!
P.S. The only time I ever resorted to PS lens correction for CA was the last time. The lens needed fixing and that was that. PS is great, but I try to get as clean an image at capture to reduce post-production....Show more →
Nope. My EF100/2 did the same thing...it's a common issue with fast lenses and isn't an issue with the copy of the lens. Go to www.photozone.de and look at the reviews for this lens (and other fast lenses). You'll see that purple fringing is a common issue. My 35/1.4L, and 50/1.2L did it as well, to some extent.
Large aperture lenses are notorious for this, especially when you are shooting anything with very high-contrast edges, like you have in these images here. Any object which is white and has a dark edge leading off of it is really going to give you issues.
I own both the 85/1.8 and the 50/1.4. Under these conditions, you are going to get these results with those lenses - its par for the course.
The in-camera solution is to stop down a bit and/or push left by 1/3rd.
Unfortunately, you have to desat the edges, but it can be done tastefully. The in-Photoshop solution is to:
1) Create a new Hue/Saturation layer
2) Zoom into your image to 200-300% where the purple fringing or CA is occurring
3) In the Hue/Sat "Adjustments" panel, choose "Magentas" for the colour
4) Of the 3 eye droppers, choose the left-most one which if you mouse over is the "eye dropper tool"
5) Use the eye dropper to click on the offending purple fringe in the image
6) Adjust the saturation of the selected colour to somewhere between -70 to -80
7) Merge layers and you're done!
I hope its okay, but I edited the image below. If it is not, let me know and I will remove it.
Because the CA's were so bad, I did one pass of this process with magenta as my selected colour, flattened the image, then did it again. Couple that with a bit of a Curves tweak, and you can see the result.
You may or may not like it:
Before:
After:
This is just a quick, 30 second fix. Obviously the groom's (?) shirt loses its magenta, but you can layer that back in easily enough. I just wanted to demonstrate my CA fixing method.
Hth and enjoy your 85/1.8! It's an outstanding little lens!
I previously owned a 85mm 1,8 and sold it because of this. Bought a 85L instead, and while it also has CA (most fast aperture canon lenses do), it's not as bad.
That is not chromatic aberration. Chromatic aberration would appear as a green halo on one side of the object and a red halo on the other and would be easily correctable in post.
What you have is what is often called "purple fringing" (or "blooming") that appears when a very bright and sharply defined area abuts a much darker area. Overexposing the light area often makes it worse.
You can minimize this when shooting by decreasing exposure a bit if the rest of the scene permits this. You can also minimize it in post during RAW conversion. I use ACR and there is a popup menu right below the controls for CA that has three options. IIRC they are, more or less, no defringing, defringing edges only, or defringing the entire image. In my experience, the third option is the one that most likely makes a difference.
There are some other ways to deal with this in post depending on how extensive the problem is and how important it is to remove it. You can manually select the fringed area and work with saturation to reduce it, for example. Doing this by "painting in" a desaturated layer along these edges can work pretty well.
This isn't really a lens issue. The 85mm f/1.8 can exhibit a small but fairly normal amount of CA but a) nothing out of the ordinary, and b) that isn't the issue here. Overall, the 85mm f/1.8 is a very fine lens, especially given its rather low price.
Just want to chime in that I got some heavy purple fringing like that with a copy of 85/1.8 that I used... It was on a 1D2 at the time, and was shooting a car, so the fringing occurred at the chrome grills under direct sun.
the real problem with purple fringing is when it occurs at an edge that is supposed to be sharp in your photo, then no fix actually fixes the problem... especially bad when you convert to b&w...
mh2000 wrote:
the real problem with purple fringing is when it occurs at an edge that is supposed to be sharp in your photo, then no fix actually fixes the problem... especially bad when you convert to b&w...
Funny you would write that - in a few cases I have decided to convert an image with significant fringing to BW precisely _because_ doing so made the fringing a non-issue. :-)
It is always important to consider what effect the fringing will or will not have in the actual final rendition of the photography. I've had some images (I'm actually thinking of one in particular as I write this) in which the fringing seemed pretty bad - but where desaturating the edges in the area of the problem rendered it essentially invisible in the final print.
I will agree, though, that truly extreme examples of purple fringing can in some cases make a photograph not worthy of recovery efforts.
