[NicoleC]

One thing I have encountered with many of my images lately is what I feel is an unattractive leaf pattern against a bright sky. In this image, I've done my best to remove the bright blue fringing that always appears around the leaves, I've desaturated much of it and reduced the contrast. Sometimes reducing the exposure in those spots helps, or making those spots a little warmer, but it didn't with this image.


Any thoughts on dealing with these kinds of issues in post processing?

[jrpower10]

I'm interested in this one myself.

[Canada_Rockies]

The purple fringe is a result of reflections between the back element of the lens and the sensor and is a nasty effect at high contrast edges. I don't know what software you are using to post process your images, so this is just something to help you see where to look. Using LightRoom 5, most of it can be removed by turning the purple saturation to zero.

You can reduce the amount of the dreaded purple fringe by stopping your lens down. I quite often use the SMC Pentax M 400mm f/5.6, which is quite prone to this problem. Around f/11 the problem starts to be reduced significantly. Of course that means the shutter speed is slower, a problem with long lenses. With shorter lenses you may find the depth of field/aperture effects result in sharpness in the image where you don't want it.

[sergysergy]

I find this problem many times. What I do in Photoshop is reduce the highlights. Then I turn the purple / blue saturation to 0 as suggested by Canada Rockies.

[mattb123]

Lightroom 5 does a good job with removing CA if you have that. There's a checkbox under the Lens Correction section in the Develop module labeled "Remove Chromatic Aberration". If that doesn't clear it all up there's a dropper tool you can use to specifically identify the trouble spots to the application. It usually does the trick.
Also, CA varies by lens and by aperture. Stopping down can help reduce it at capture time.

[Oldbayrunner]

First off looking at your exif on flickr, I find it better to not use auto white balance in these types of situations as it will tend to render a bluish cast a good portion of the time.

Please don't take this wrong, I personally don't think the use of F9, 1/50 & ISO 800 was the best choice for the scene to start with for a few reasons. To me It would seem the scene was in open shade, which afaik would be an EV of around 11, so if it were then and one wanted to maintain a deeper depth of field one may have had better exposure results by using an ISO of around 100, F8 and 1/30 (or f 5.6 and 1/60). If one wanted to use ISO 800 at that EV then F8 & 1/250 may have rendered a better exposure triangle at that ISO but one would need to adjust in post for much more noise if shot in raw. .Afaik the Da 15mm isn't prone to a large amount of CA, even so as others have mentioned that would be an easy fix in Lightroom.

[Madaboutpix]

Lightroom 5 does a good job with removing CA if you have that. There's a checkbox under the Lens Correction section in the Develop module labeled "Remove Chromatic Aberration". If that doesn't clear it all up there's a dropper tool you can use to specifically identify the trouble spots to the application. It usually does the trick.
Also, CA varies by lens and by aperture. Stopping down can help reduce it at capture time.

Spot on, Matt. Interestingly, with some lenses - notably the DA 35mm Macro and the DA* 55mm - CA actually *increases* with stopping down (cf. reviews of these over at slrgear.com). Which is not the most typical of lens behaviours, though.

BTW, Lightroom users have had those dedicated CA correction options on board since v4.0. Agree that they work fairly well. I use them often, and particularly with the dropper tool those twigs-and-foliage-against-bright-sky situations have become a lot more manageable.

---

Last edited by Madaboutpix; 11-03-2014 at 02:39 PM. Reason: Wrong LR version number - how could I be so stupid?

[LensBeginner]

You can stop down and underexpose - that way you'll also preserve the sky...
Obviously be careful... a 2-stop underexposure will usually mean that you'll have quite a bit of noise and a loss of detail & color in the shade...
A plus is that it will partially counteract the slowing of the shutter speeds that stopping down entails.

[NicoleC]

Thanks for the input.

Please don't take this wrong, I personally don't think the use of F9, 1/50 & ISO 800 was the best choice for the scene to start with for a few reasons.

I asked for input; criticism is welcome. I was actually in pretty dark shade when I took the image. I would have preferred an even deeper DOF but I was hand holding and it was windy, so I needed the most shutter speed I could get. I tried to balance the needs. No doubt I could have done better; the image is also not really sharp.

IME, I have a lot of CA issues with the 15mm, but I'm inclined to think a lot of that is the type of shots with it instead of necessarily a problem with the lens.

I did underexpose the image and use the CA dropper tool in LR. It helps enormously. I cut the blue saturation, but I really needed purple for the leaves along the bank.

Interestingly, with some lenses - notably the DA 35mm Macro and the DA* 55mm - CA actually *increases* with stopping down (cf. reviews of these over at slrgear.com). Which is not the most typical of lens behaviours, though.

That's an interesting idea for a test for this lens. I'll have to check that out.

Here's a comparison with the original:

[LensBeginner]

Thanks for the input.

*snip*
IME, I have a lot of CA issues with the 15mm, but I'm inclined to think a lot of that is the type of shots with it instead of necessarily a problem with the lens.

*snip*

Well, of course it's more noticeable in thin black objects like branches... you can clearly see the two colored edges, whereas you wouldn't notice it as much on a similarly colored object.

[Oldbayrunner]

I noticed a -1 EV exposure bias but didn't mention it previously, was that done in camera or post process? If you were in a dark shade and adjusting for that why would you need to use a negative 1 EV adjustment? In my mind with the higher noise factor the use of a higher ISO would compound problems in the darker areas, not saying your lens may not be experiencing CA issues.

Food for thought, even though the DA 15 is a wide angle lens with a deep depth of field one needs to keep in mind distant objects wouldn't appear sharper at any F stop unless the lens were focused at it's hyperfocal distance which would produce the deepest depth of field for the lens and scene, I venture to say in checking the use of f9 it would have been somewhere around 4 ft. From my experience in landscape photography hyperfocal distance focusing is something to keep in mind and use when needed.

[NicoleC]

I noticed a -1 EV exposure bias but didn't mention it previously, was that done in camera or post process? If you were in a dark shade and adjusting for that why would you need to use a negative 1 EV adjustment?

-1 in camera so as not to blow out the sky. It was very bright and clear that day. In post I bumped the exposure in the foreground and shaded areas. I was using a circular polarizer, which may have helped, but I wanted the reflections in the water.


I'm telling you what I did, but not necessarily defending it. You see, there's a story behind this photo.


We were out hiking, took a wrong turn (on my advice) and a downhill mile later came to a dead end and realized we'd have to hike the mile back uphill. My husband was very annoyed and insisted "I might as well take pictures while we are here." So, I took some (including this one) to appease him. But in the back of my head I was thinking we were a mile deep into different piece of private property, without permission, in the woods in hunting season. And not wearing blaze orange. I was NOT going to linger! I spent maybe three minutes with the camera and high tailed it out of there.

If I were not rushing, I probably would have set up the tripod and taken multiple shots for focus stacking and different exposures for the 3 distinct light areas in the photo. Or played with a long exposure and used my hat to create a gradient exposure on the sky portion. And maybe got a great photo out of it, which this one certainly is not.


I did think it was useful for illustrating the high contrast tree situation. As the sun gets lower in the sky it seems to becomes more of a problem. I used all the post processing techniques mentioned so far, I think, but it never occurred to me to test how this particular lens does at different stops.

[Oldbayrunner]

LOL great story... I'm not trying to be critical, just trying to understand the thought process vs my own. I have been experimenting shooting a bit recently in this same similar type of canvas using much lower settings and manually adjusting my wb because I haven't been happy with the wb presets..

[mattb123]

I would have done the same with the -1 ev. Exposing for the bright areas and bringing up the shadows is often a good way to deal with light like this. Of course a lower ISO would help but given the situation I think you did reasonably well.

I'm usually the one who leads my wife into the unexpected hill climb or something like that. I know the feeling!

[gor80]

CA it is very often the case in such circumstances as backlight illumination - leaves, twigs. Even on the very expensive lenses, more than 1 thousand $ only it is less noticeable, but still there.
Usually I do not attach any importance to this and to remove the CA I use a lightroom.