Is any amount of CA acceptable?

[Colin Houck Photography]

Hi all, I am new here, and am looking for some clarity on the subject of chromatic aberration. With regards to Alamy QC, how stringent are they when it comes to CA? Specifically, will they, more likely than not, fail a photo if it has, say, barely noticeable CA (@ 100% crop) in an OOF background? When I say barely noticeable, I mean you'd have to really search for it, and even then, it could possibly be attributed to natural color in the scene. 

[Betty LaRue]

All I can say about that is I had a beach scene and missed a tiny bit of CA on a palm tree frond in the upper left corner. My focus was on people in beach chairs. It failed.

Either crop it out or use the eye dropper and sliders in LR which is very effective. It works on purple fringing too.

[AlessandraRC]

I don't know. I take a long, long time erasing everything that might look like ca. I don't even know if some of it is passable or not, but I have a am a little obsessed with CA. 

[John Mitchell]

I've found that images with a bit of unavoidable red flare, fringing (or whatever it's called) pass QC. If there is no accompanying "cyan" fringe, then it often isn't CA.

[MDM]

Hi all, I am new here, and am looking for some clarity on the subject of chromatic aberration. With regards to Alamy QC, how stringent are they when it comes to CA? Specifically, will they, more likely than not, fail a photo if it has, say, barely noticeable CA (@ 100% crop) in an OOF background? When I say barely noticeable, I mean you'd have to really search for it, and even then, it could possibly be attributed to natural color in the scene. 

 

If its barely noticeable and out of focus (OOF), then I would guess it is completely insignificant and should not be a cause for concern.

[spacecadet]

I've had some problems in the past but the LR CA correction tickbox has always been sufficient.

Beware of confusing colour flare with CA.

[MDM]

CA's on very OOF parts is also going to cause a fail, so the whole image needs to be checked for it (often other things like dust can show up more in blurred areas).

 

 

I'm surprised if that is the case but it sounds like you know what you are talking about from experience. I was just going on intuition rather than actual experience in stating that it is unlikely to cause a problem in out of focus areas.

[Betty LaRue]

Hard to say. I had several fails in a period of months so I think my images were checked more closely than someone with no fails.

It's always possible someone who has a clean record gets the nominal few images checked out of a submission so that a bit of CA might slip through on an image that wasn't checked and caught.

 

If you get a fail, I think a few more images out of a submission might be checked for a while, (if not every single image) so a bit of CA might stand a higher chance of being caught and punished.

But then....I can't presume to know the minds of those in QC, or how each individual may differ from the next QC person. They aren't robots, so there may be differences in how they do their jobs.

Bottom line is just because you had some CA go through, it doesn't necessarily mean it was seen by QC.

[AlessandraRC]

This is not a matter of fail or not, QC. Imagine for each image, the customer might want to make a large poster, and do you want the customer to notice something ugly and get upset, never buy from you again, or even worse, return the image? 

[Colin Houck Photography]

Thanks all, the image in question passed initial (my first) QC, as did all the rest. I'll be honest, after reading in these forums how many folks get failed for seemingly small imperfections, I was certain that all four of my images would fail miserably. 

 

I use the color blur layer method for CA removal, and obsess pretty heavy about it, but I have one lens (Sigma EX 10-20mm f 4-5.6) that I love dearly, but suffers from considerable CA at anything below f/ 8, and at any aperture in high contrast lighting, and editing can get tedious and time consuming, resulting in missed CA when it's not very noticeable.

 

Anyway, thanks again, and I look forward to being part of the Alamy family.

[MDM]

I use the color blur layer method for CA removal, and obsess pretty heavy about it, but I have one lens (Sigma EX 10-20mm f 4-5.6) that I love dearly, but suffers from considerable CA at anything below f/ 8, and at any aperture in high contrast lighting, and editing can get tedious and time consuming, resulting in missed CA when it's not very noticeable.

 

 

 

Why not use the Remove CA tickbox in LR/ACR. Works wonders on lateral CA in general.

[Colin Houck Photography]

 

I use the color blur layer method for CA removal, and obsess pretty heavy about it, but I have one lens (Sigma EX 10-20mm f 4-5.6) that I love dearly, but suffers from considerable CA at anything below f/ 8, and at any aperture in high contrast lighting, and editing can get tedious and time consuming, resulting in missed CA when it's not very noticeable.

 

 

 

Why not use the Remove CA tickbox in LR/ACR. Works wonders on lateral CA in general.

 

Because I find it doesn't get it all, and though it's not one of my best qualities, I'm a bit of an anal-retentive "arse" (can I say that here?).

[spacecadet]

 

 

I use the color blur layer method for CA removal, and obsess pretty heavy about it, but I have one lens (Sigma EX 10-20mm f 4-5.6) that I love dearly, but suffers from considerable CA at anything below f/ 8, and at any aperture in high contrast lighting, and editing can get tedious and time consuming, resulting in missed CA when it's not very noticeable.

 

 

 

Why not use the Remove CA tickbox in LR/ACR. Works wonders on lateral CA in general.

 

Because I find it doesn't get it all, and though it's not one of my best qualities, I'm a bit of an anal-retentive "arse" (can I say that here?).

 

Since using the tickbox I don't find it necessary to check for CA myself unless there are very high-risk areas.

[Colin Houck Photography]

 

 

 

I use the color blur layer method for CA removal, and obsess pretty heavy about it, but I have one lens (Sigma EX 10-20mm f 4-5.6) that I love dearly, but suffers from considerable CA at anything below f/ 8, and at any aperture in high contrast lighting, and editing can get tedious and time consuming, resulting in missed CA when it's not very noticeable.

 

 

 

Why not use the Remove CA tickbox in LR/ACR. Works wonders on lateral CA in general.

 

Because I find it doesn't get it all, and though it's not one of my best qualities, I'm a bit of an anal-retentive "arse" (can I say that here?).

 

Since using the tickbox I don't find it necessary to check for CA myself unless there are very high-risk areas.

 

I'll keep that in mind, and maybe take another look. I'm encouraged by Alamy QCs seemingly less stringent than my own exacting standards. It's always good to have an opportunity to ease up on the PP.

[Betty LaRue]

I check everything at 100%, so while I'm checking for sharpness, dust spots, etc I will spot CA anyway.

[dustydingo]

 

This is not a matter of fail or not, QC. Imagine for each image, the customer might want to make a large poster, and do you want the customer to notice something ugly and get upset, never buy from you again, or even worse, return the image? 

 

 

If you're looking at 100%, as you should be, and can still barely see any CA, then no size of print will show it up any more.

 

Geoff.

 

 

that's true, but I believe Allessandra's point still stands at least as a general principle: if it can be seen, even "barely seen", it may be enough for the customer to demand a refund . . . and that (the possibility of a refund) is, I think, a more important consideration, from a business point of view, than whether or not it will get through QC.

 

dd

[AlessandraRC]

We need to remember that an image may pass QC even though it has flaws simply because it hasn't been inspected closely. Alamy does not inspect all images in a batch unless, I guess, there is only one in the batch. We need to be our own QC, as if we were working for ourselves. Obviously the inspector and us may disagree about the technical acceptability of an image, but I would avoid inserting something in with the hopes that it will not be inspected.

 

It is true that some things we can see at 100% might not show, but it is too expensive to print every image to see what you can/cannot see.

[Colin Houck Photography]

FTR, The image in question was one of my initial 4, so it was inspected.

 

See if you can find any CA:

 

http://i1194.photobucket.com/albums/aa362/OregonColin/CCH_6687_zps1tyawjkc.jpg

[ManWay]

I just use the simple, quick click in Remove CA tickbox in LR/ACR.

 

For the fees Alamy are currently charging for licenses of images (next to nothing in most cases - microstock really) it's just not worth the time to do any more than this.

 

For private clients and people paying "top dollar" I would spend a bit more time.

 

Alamy now has just too many images to really care about protecting photographers. It matters little to them whether an image is licensed for $2 or $20. In fact they'd rather sell the license AT ANY PRICE because there are so many images available - 70 million or so.

[MDM]

FTR, The image in question was one of my initial 4, so it was inspected.

 

See if you can find any CA:

 

http://i1194.photobucket.com/albums/aa362/OregonColin/CCH_6687_zps1tyawjkc.jpg

 

In my opinion, you are making a fuss out of nothing and wasting time correcting CA manually instead of applying a universal lateral CA remover (0 seconds if you apply it as a default or import preset). Significantly out of focus areas are almost certainly irrelevant as far as Alamy QC is concerned - maybe dust spots  matter but certainly not a bit of colour fringing in out of focus areas. It's pretty much the same as worrying about the quality of bokeh - completely irrelevant. If that was my picture, I would have put a grad filter in LR/ACR on the light area that is the cause for concern, darkening it a lot so that is doesn't distract the eye from the main subject - the bike. That would be about 10s work. I think the Milky Way photo is great by the way.