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Lightroom : automatic lens correction

Posted: Wed Jun 30, 2010 7:22 am
by hercules
Hello,

Is someone using the automatic lens correction in lightroom, and if yes, have you created the profiles yourself, or found it in a secret place somewhere?
Eventually I would try to create them myself, the process seems to be well documented, just not sure about quality...

thanks!

Re: Lightroom : automatic lens correction

Posted: Wed Jun 30, 2010 6:15 pm
by David Kilpatrick
The sheer number of images you must take to profile a lens is enormous. We will be trying out the automatic correction on Sigma 12-24mm and Sigma 18-250mm shots very shortly, pix taken, just waiting to be processed. All current Sigma lenses have full profiles.

I may try creating a lens profile, but it's a half day's work at least for a single zoom lens properly set up.

David

Re: Lightroom : automatic lens correction

Posted: Wed Jun 30, 2010 6:46 pm
by bakubo
David Kilpatrick wrote:We will be trying out the automatic correction on Sigma 12-24mm and Sigma 18-250mm shots very shortly, pix taken, just waiting to be processed. All current Sigma lenses have full profiles.
Please let us know how that goes.

Re: Lightroom : automatic lens correction

Posted: Wed Jun 30, 2010 8:09 pm
by roysmith
David Kilpatrick wrote:The sheer number of images you must take to profile a lens is enormous. We will be trying out the automatic correction on Sigma 12-24mm and Sigma 18-250mm shots very shortly, pix taken, just waiting to be processed. All current Sigma lenses have full profiles.

I may try creating a lens profile, but it's a half day's work at least for a single zoom lens properly set up.

David
Well that explains why DxO takes so long to add new lens correction modules. And it should take longer for them because they do CA and softness correction as well.
It's a shame they won't add user-made modules support as ACR does, as it would be useful for my unsupported Sigma lenses in my A700.

Re: Lightroom : automatic lens correction

Posted: Wed Jun 30, 2010 9:32 pm
by bakubo
roysmith wrote:Well that explains why DxO takes so long to add new lens correction modules. And it should take longer for them because they do CA and softness correction as well.
I was thinking that I read somewhere that the new LR corrects distortion, vignetting, and CA. Is that wrong?

Re: Lightroom : automatic lens correction

Posted: Wed Jun 30, 2010 9:39 pm
by roysmith
bakubo wrote:
roysmith wrote:Well that explains why DxO takes so long to add new lens correction modules. And it should take longer for them because they do CA and softness correction as well.
I was thinking that I read somewhere that the new LR corrects distortion, vignetting, and CA. Is that wrong?
Sorry for some reason I assumed the correction was for distorsion only. But you're right, Adobe's site says it also corrects CA and vignetting. Doesn't mention anything about softness though. AFAIK "lens softness correction" is some kind of custom, zonal USM.

Re: Lightroom : automatic lens correction

Posted: Thu Jul 01, 2010 1:51 am
by David Kilpatrick
I can't yet tell you how the CA etc correction works, but it is easy to see the distortion correction in LR3 by clicking the tick box on and off. You lose a fair amount of lens angle, all too often.

David

Re: Lightroom : automatic lens correction

Posted: Thu Jul 01, 2010 2:36 am
by bakubo
David Kilpatrick wrote:I can't yet tell you how the CA etc correction works, but it is easy to see the distortion correction in LR3 by clicking the tick box on and off. You lose a fair amount of lens angle, all too often.
Yes, when there is a lot of distortion I lose some of the lens angle when I correct with PTLens too. Most of the time it isn't important, but sometimes it is. I use PTLens when the distortion is important, but don't use it when I judge it isn't. Also, sometimes I actually prefer the distorted photo. For example, with wide angle I notice that often people near the edges look better without correction.

Re: Lightroom : automatic lens correction

Posted: Sun Jul 25, 2010 12:08 pm
by harvey
David Kilpatrick wrote:The sheer number of images you must take to profile a lens is enormous. ...
David
I have been trying to work out how much effort this would be for me to profile my 17-35 f/2.8-4 (D).
There are also multiple target sizes and grid resolutions to choose from.

Harvey

Re: Lightroom : automatic lens correction

Posted: Thu Sep 02, 2010 7:04 am
by UrsaMajor
It is my understanding that the KM 28-75mm f:2.8 lens is optically the same as the Tamron 28-75mm f:2.8 lens, with the exception of lens coatings. In looking at the list of lenses in the correction database of the just-released LR 3.2, I see very few Sony lenses and no KM lenses, but it does include the Tamron 28-75mm f:2.8. At first blush, I assume that the Tamron lens correction data could be used as a surrogate for the KM lens. Is this a valid assumption?

Also, there seem to be a large number of Tamron 28-75mm f:2.8 lenses in the LR list with very minor differences in the name. I have not found a table that defines the differences - if any - between these lenses, so I wonder if anyone knows the naming convention for the variations on this lens. I assume that the 28-75mm f:2.8 lens with the name that ends in Di A09S is the relevant one for use on a Sony camera, but I have not found confirmation of that viewpoint. Is that a valid assumption?

With best wishes,
- Tom -

Re: Lightroom : automatic lens correction

Posted: Thu Sep 02, 2010 12:13 pm
by David Kilpatrick
The Tamron profiles just release by Adobe are faulty, I've alerted the labs forum to the problem. As an example -

Image
Normal Tamron 10-24mm preview

Image
With the 10-24mm profile applied.

There appear to be some profiles which work OK, like the 18-250mm, and others which are a disaster like this. The camera make differences have no effect. Looks like someone just renamed the same profile to make it pop up for Sony, Nikon, Pentax and Canon.

David

Re: Lightroom : automatic lens correction

Posted: Thu Sep 02, 2010 4:37 pm
by UrsaMajor
David Kilpatrick wrote:The Tamron profiles just release by Adobe are faulty, I've alerted the labs forum to the problem.
There appear to be some profiles which work OK, like the 18-250mm, and others which are a disaster like this. The camera make differences have no effect. Looks like someone just renamed the same profile to make it pop up for Sony, Nikon, Pentax and Canon.
Do you happen to have a list of the lens profiles you've checked, and which ones seem to be good? So far I have not applied any of the Tamron profiles from the LR 3.2 release, so I have no personal experience with them yet.

With best wishes,
- Tom -

Re: Lightroom : automatic lens correction

Posted: Thu Sep 02, 2010 4:49 pm
by David Kilpatrick
The profiles include the 17-50mm, 18-200mm, 18-250mm, 10-24mm, 28-75mm, 90mm macro, and 70-200mm f/2.8. The 70-300mm, 11-18mm, 17-35mm and others are missing.

So far the only ones I have got to show a reasonable result are the 18-250mm and 28-75mm, but the 28-75mm is still wrong, it's overcorrecting something which needs zero correction.

Clearly the entirely set for Tamron is simply not correctly produced, while the Sigma set is all OK if a bit basic (tending to undercorrect).

David

Re: Lightroom : automatic lens correction

Posted: Thu Sep 02, 2010 5:16 pm
by UrsaMajor
David Kilpatrick wrote:So far the only ones I have got to show a reasonable result are the 18-250mm and 28-75mm, but the 28-75mm is still wrong, it's overcorrecting something which needs zero correction.
Thanks for the information. It sounds like I'll want to hold off using the Tamron 28-75mm f:2.8 correction for my KM 28-75mm lens.

With best wishes,
- Tom -

Re: Lightroom : automatic lens correction

Posted: Thu Sep 02, 2010 7:14 pm
by David Kilpatrick
You will find there is a whole bunch of 28-75mm corrections, with a similar name, and then one original one with a shorter name. This one is perfect. It's the original one which was released with 6.1. It is correct, the new ones are not correct.

David