Jump to content

Recommended Posts

Hmm. The one before is worse.

It does all rather confirm that after the first (and second) offences one is more carefully watched.

Odd that the first post-fail batch was failed in an hour. Perhaps they took pity on me.

No sign yet. of the subsequent batches though. Fingers crossed overnight.

Thanks Martin and all.

Share this post


Link to post
Share on other sites

Pity really because for most uses, especially web, the CA would not be a problem.

 

It gives me something else to look out for especially whenpicking up some forgotten, older images. My current kit is pretty sound in the CA department, I think!

Edited by Martin P Wilson

Share this post


Link to post
Share on other sites

There are still dark marks either side of the pole / rope or whatever it is at the top of the image......  I've looked at it on two computers, so it's not my screen.  It's grey / black against the blue sky.

Share this post


Link to post
Share on other sites

Sony 18-55 kit. It's never been an issue before.

 

I have hundreds of images on Alamy that were taken with a Sony 18-70 kit lens. Can't remember having a single CA failure with it, but QC is much stricter now. Many of those images wouldn't pass today. I used a program called PTLens to clean up CA at the time. Have subsequently sold that particular kit. As mentioned, current Sony cameras have built-in CA correction. Works like a charm, even with iffy wide angles. Don't believe the a55 has that feature, though.

Edited by John Mitchell
  • Upvote 1
  • Downvote 1

Share this post


Link to post
Share on other sites

To my eyes, the biggest problem in both corrected and uncorrected versions is the purple fringing around the face, and the hair in front of face, of the girl on the right.

 

Definitely a fail in my books.

 

Good to see a 100% example of a QC fail. Thanks. It's very helpful. 

Edited by M.Chapman
  • Upvote 1

Share this post


Link to post
Share on other sites

It's a jpg. Some correction in LR works but I must have dozens of worse examples up. It's not a routine item for me- or rather, it wasn't

I simply can't see it at 100%.

Phil-bollards.

Bollards to you too :P  ;)

Share this post


Link to post
Share on other sites

A way to help if CA tool isn't enough…..

 

In PS duplicate layer.

Change blend mode to colour.

Go to Filter-Blur-Gaussian blur.

Adjust to about 3 - 5, checking image to see CA disappear.

Add layer mask. Fill with black. Paint back in white on areas you want.

 

I sometimes use this if I think the image is worth the work.

  • Upvote 2

Share this post


Link to post
Share on other sites

As Keith mentioned above your corrected version still shows some CA.

 

I checked in Photoshop and simply ticking the CA removal box in Camera RAW does 90% of the job. There's still a tiny bit of fringing in the corners of the image and along the girl's face as others have mentioned which can be cleaned using the fringe sliders.

 

I  think even 'borderline' CA should probably constitute a fail as it's just such an easy thing to fix in 99% of cases. Offtopic: I also notice some JPG artifacts in the sky, and along the rope in top of frame which you may want to clean up before resubmitting. 

 

Interesting to see a full-size CA failure, thanks for posting.

 

-Jason

  • Upvote 1

Share this post


Link to post
Share on other sites

OK, now I see the CA. I had clicked on the magnifying glass only once. Too messy for sure. QC now expects no CA at all, it seems. 

 

Tough lighting situation as well with all the white paint, high contrast areas, and harsh sunlight. I recently took a bunch like these on a ferry in the middle of the day and canned the lot for various reasons.

 

P.S. It might be worth downloading a trial version of PTLens (see my post above). I think it might be able to clean these image up. Worth a try, anyway.

Edited by John Mitchell

Share this post


Link to post
Share on other sites
Guest

It's an easy fix, just paint using a color mode layer, ideally with a Wacom for speed. Global CA fixes only go so far and then degrade too much.

Share this post


Link to post
Share on other sites

1+ for PT Lens, which I've had to use in the past for a really bad lens (Sigma 12-24). Now ACR takes care of most of CA. However with the Sony RX100 I see similar problems as with this Sony. The RX100 is a lot less easy to correct though.

Here's a sample of the Sony 18-55 at 18mm and F8. When I see this I would never think of trying to use a straight JPG from this lens. Only RAW.

 

wim

Share this post


Link to post
Share on other sites

The simple thing to do would have been to remove my customary +20 saturation preset.

With a defringe it's now much better. Not vanished though and I will try the various PS tips if I can work out how!

Thanks all.

I really have spent far too much time on this image- hope none of you feel the same way!

http://i5.photobucket.com/albums/y180/markrhdunn/DSC01817-3.jpg~original

Edited by spacecadet

Share this post


Link to post
Share on other sites

1+ for PT Lens, which I've had to use in the past for a really bad lens (Sigma 12-24). Now ACR takes care of most of CA. However with the Sony RX100 I see similar problems as with this Sony. The RX100 is a lot less easy to correct though.

Here's a sample of the Sony 18-55 at 18mm and F8. When I see this I would never think of trying to use a straight JPG from this lens. Only RAW.

 

wim

 

I'm using the Sony e-mount 18-55, and JPEGS with in-camera (NEX-6) CA correction turned on are as clean as a whistle. I also use this lens with my "old" NEX-3, which doesn't have in-camera CA correction, and I can usually easily clean up any CA with PTLens. I've never had a CA failure. Haven't used the Sony A-mount 18-55, though.

Edited by John Mitchell

Share this post


Link to post
Share on other sites

This is where good glass really earns its money. I recently bought the Canon 100mm 2.8L IS Macro lens, having used mostly kit lenses before or 18-200mm zoom. This prime lens has made all the difference. I used to spend HOURS getting rid of CA, now it is no longer a problem for me. I will using primes only from now on.

Share this post


Link to post
Share on other sites

The simple thing to do would have been to remove my customary +20 saturation preset.

With a defringe it's now much better. Not vanished though and I will try the various PS tips if I can work out how!

Thanks all.

I really have spent far too much time on this image- hope none of you feel the same way!

http://i5.photobucket.com/albums/y180/markrhdunn/DSC01817-3.jpg~original

 

Yes, good thing we're getting paid by the hour. B)

 

I still see CA -- e.g. around the girl's (one snapping the picture) shoulder, under her hair, and along the diagonal supports or whatever they are. No problem submitting this a couple of years ago. But not now IMO.

Edited by John Mitchell
  • Downvote 1

Share this post


Link to post
Share on other sites

The simple thing to do would have been to remove my customary +20 saturation preset.

With a defringe it's now much better. Not vanished though and I will try the various PS tips if I can work out how!

Thanks all.

I really have spent far too much time on this image- hope none of you feel the same way!

http://i5.photobucket.com/albums/y180/markrhdunn/DSC01817-3.jpg~original

 

Mark-

 

The CA is still very apparent unfortunately. No photoshop trickery needed, just tick that little box!!

http://www.reciprocityimages.com/images/temp/spacecadet_CA.jpg

 

That is the JPG simply opened in Camera RAW and the Remove CA check bock ticked... Cleans up easily after that with remove fringe sliders. Not magic. Takes two seconds! Shooting RAW would of course give higher quality correction!

 

It's not about this particular image- You've only spent too long on it if you haven't learned something for the next batch.  :)

 

-Jason

  • Upvote 1

Share this post


Link to post
Share on other sites

My ACR only has the sliders. There's no 'remove ca' box.

Share this post


Link to post
Share on other sites

My ACR only has the sliders. There's no 'remove ca' box.

Strange? It doesn't look like this:

http://www.vineet-suthan.com/photoblog/wp-content/uploads/2013/02/PhotoshopScreenSnapz002.jpg

Which version? This has been an option as far a I can remember, but perhaps not.

 

Do you have LR? The controls are identical.

 

-Jason

Share this post


Link to post
Share on other sites

I only have CS4 and LR2.

My mistake- You camera RAW version would be probably 5.7 which does not have the tick box!!

 

Maaaybe worth a LR upgrade, as perhaps you are spending more time with correcting and QC failures than you are saving money?

 

Otherwise, when you do your CA correction, try at 200-400%. If you are having trouble seeing the CA that is there this may help adjust the sliders properly.

 

-Jason

Share this post


Link to post
Share on other sites

Alamy income doesn't justify upgrades, sorry.

As to 400%, whatever happened to images only having to pass at 100%? Have the goalposts not only moved, but been magnified?

Share this post


Link to post
Share on other sites

Alamy income doesn't justify upgrades, sorry.

As to 400%, whatever happened to images only having to pass at 100%? Have the goalposts not only moved, but been magnified?

No reason to be sorry, was just a suggestion- it's your decision and does not affect me!

 

The CA is clearly there at 100%. I only suggested looking at higher magnification for correction as you said you could not see it. It just might be easier to dial in the correction with a bit more precision.

 

-Jason

  • Upvote 5

Share this post


Link to post
Share on other sites

As to 400%, whatever happened to images only having to pass at 100%? Have the goalposts not only moved, but been magnified?

 

I can't see anyone other than you suggesting images have to be approved at higher than 100%, which is plain silly.

 

Jason's suggestion, for someone who can't see the CA at 100%, was an excellent one that I think deserves thanks, not distortion. But of course, that's just how I see it . . .

 

dd

  • Upvote 4

Share this post


Link to post
Share on other sites

I can see the CA quite a lot in that image. All round the girl on the lefts hair and all over the hills. Usually quite apparent at the edges anyway on most lenses I think. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.