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mronen
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Tutorials on ACR 6.1 new Lens Correction features

Jun 5, 2010 11:08 PM

Hi,

 

We are all experienced users of cameras/Photoshop/ACR etc., and wizards at learning by trial-and-error, but I think it might be really helpful if there was a good tutorial (preferably by Adobe), to deal with the new features of lens corrections in ACR 6.1, to take out some of the guesswork.

 

There are items to be addressed, like for instance, the difference between Default-Auto-Custom in Lens Profiles page, why the lens profiles seem to depend only on lens type, while in Photoshop they depend on Camera/Lens combinations, how to prevent double correction, and many others.

 

If anyone knows of such tutorials, I'll be grateful if they can share.

 

Thanks,

Moshe

 
Replies
  • Currently Being Moderated
    Jun 6, 2010 7:19 PM   in reply to mronen

    Double-correction: You do not have to worry about double-correction if you're processing raw files. For non-raw files, that's something you'll have to keep track of. ACR does not keep track of whether lens corrections are applied non-raw files (e.g., lens corrections already applied by camera, or in PS via PS's own lens corrections filter, or other software).

     

    Lens "Setup" menu explanation:

     

    - Auto means that you ask CR to find a lens profile automatically for your image, and sets the Correction Amount sliders to 100. If Auto can’t find a profile for your image, then it sets the profile to “None” (and shows a small warning icon and message explaining this).

     

    - Default is the same thing, but you can customize it (i.e., custom default for your camera + lens combination).

     

    - Custom is just that: custom. If you manually change a profile or one of the Amount sliders, you’re doing a custom adjustment, so Setup gets set to Custom.

     

    Regarding lens vs camera+lens combinations. Generally, Adobe only supplies 1 profile per lens. Differences between cameras (e.g., crop factors) are automatically taken into account when applying the profile.

     

    General usage model: Check the "Enable Lens Profile Corrections" box to apply lens corrections. In many cases, that's all you need to do. If needed, use one of the popups to select/change the profile. If needed, adjust the "Correction Amount" sliders to modify the correction.

     
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    Jun 7, 2010 6:48 AM   in reply to MadManChan2000

    Eric, what about cameras with forced lens correction like Panasonic LX3. If I make a profile with ALPC, will it profile the "real" lens distortion or distortion visible after the forced behind-the-scene correction?

     

    Will I get double-correction?

     

    Is it possible to cancel the forced correction, now that we have user-controlled lens correction (say, I select the self-created LX3 profile from the menu and set the distortion slider to 0)?

     
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    Jun 7, 2010 8:01 AM   in reply to MadManChan2000

    It's also important to realize that if you proceed beyond the warning that no profile is available, and persist in a correction, a file will be picked for you, highlighted in the tables.  All you have to do is pick your camera manufacturer and you will see a correction applied, even though the message says no profile available.

     

    I regard that as an operational error.

     
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    Jun 7, 2010 10:13 AM   in reply to Dorin Nicolaescu-Musteață

    dorin_nicolaescu wrote:

     

    Eric, what about cameras with forced lens correction like Panasonic LX3. If I make a profile with ALPC, will it profile the "real" lens distortion or distortion visible after the forced behind-the-scene correction?

     

    It will profile only the lens defects left after the auto correction ACR is doing by default and no, you can't turn those off (at least at this point).

     
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  • Currently Being Moderated
    Jun 7, 2010 11:28 AM   in reply to Jeff Schewe

    I rally am confused now. If I am following you, running ALPC, ACR first applies any corrections in it's data base, then applies the corrections submitted to it through ALPC? OW! My head hurts!

     

    There seems to be no "clean slate" start here. And ALPC sounds worse than ever.

     

    I am requesting that all Lens Corrections processes be under strict control of the user, which means tuning them off in any case where the program goes out to search for corrections. Otherwise, I'll be forced to revert to CS3 or PTGui for some of my processing when stitching. This is not what I paid for by upgrading.

     

    Adobe needs the attitude Sinar took to dealing with correction errors in camera movements when it went to not only the basic movements, but things like yaw, depth of field scales, two point focusing, etc all of which made my life easier, not harder. After the p and f series came out, no other view camera came close.

     

    I expect no less from Adobe,

     

    Thank you.

     
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    Jun 7, 2010 1:40 PM   in reply to Hudechrome

    You are making it more complicated than it is. Certain point and shoot cameras will have auto lens corrections applied. You can't currently turn them off. If you try to create your own custom profiles with ALPC you'll be running the profile generation on top of what has already been applied.

     

    Hudechrome wrote:

    I am requesting that all Lens Corrections processes be under strict control of the user, which means tuning them off in any case where the program goes out to search for corrections. Otherwise, I'll be forced to revert to CS3 or PTGui for some of my processing when stitching. This is not what I paid for by upgrading.

     

     

    Well, feel free to revert back to CS3 when using your cheap point and shoot cameras where the lens correction will be applied whether you like it or not. If you are using a DSLR the previous discussion isn't relevant to you.

     
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    Jun 7, 2010 2:28 PM   in reply to Jeff Schewe

    Hmm, the LX3 is not exactly cheap but yes, it isn't a DSLR. And the discussion as you framed it does affect me because of the DXO corrections already in place. No, I am not going to create my own profiles with the Profile creator. But I don't want any part of PS doing an Auto Correct w/o my ok. What the LX3 is doing is only the start, and were I running a camera system which, for the price of software development, correct any and possibly all the errors uncorrectable at the price point for my lenses in this world economy (if we can even call it that today!), I would do it in a heartbeat, and I would make it available in RAW.

     

    I also do not appreciate your demeaning attitude. You know nothing of my background that even hints at the conclusions you stated in the last sentence.

     
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    Jun 7, 2010 2:54 PM   in reply to Hudechrome

    Hudechrome wrote:

     

    I also do not appreciate your demeaning attitude. You know nothing of my background that even hints at the conclusions you stated in the last sentence.

     

     

    Hum...well I'm not super fond of your Chicken Little "the sky is falling" attitude either...this thread is about learning how to use Lens Corrections in Camera Raw, not about whether or not you are gonna quit using Photoshop CS5 and revert to CS3 as some sort of political statement about choice.

     

    As for the LX3, yes, it's a cheap point and shoot camera...any camera under $500 is cheap...and it's ONLY the cheap point and shoot camera makers who begged Adobe to do the auto lens corrections...and no, you can't turn them off.

     

    As far as the rest of the Lens Corrections in Camera Raw and Photoshop CS5, maybe if you actually took the time to learn how to use the functionality you wouldn't be so filled with angst. As long as you don't tell Camera Raw to do auto or default lens corrections by DEFAULT, you won't have to worry about lens corrections ever being applied. Same thing in Photomerge...uncheck the distortion and vignetting options and Photomerge won't use them.

     

    You really are making things far more complicated than they are...

     
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    Jun 7, 2010 4:17 PM   in reply to Jeff Schewe

    The "Chicken Little" as you call it, isn't aimed at you, unless you want to claim ownership. It isn't mine either. The sky's not falling but there are a few heavy showers about.

     

    I have taken the time and if you examine what I said, I am including the auto corrections in PhotoMerge as part of the whole. Particularly Photomerge at this point.

     

    If you have taken the time to read what I said I pointed out that Lens Correction will attempt to correct the image if you ignore the warning that no profile exists. I couldn't know that unless I tested it.

     

    If you took the time to read my posts earlier in the Profile Creator Forum, would would know that I actually ran tests on the Lens Profiler for the one lens in Adobe's collection I use, against the DXO output and found Adobe's correction way out of line. And to put to rest the notion I don't know what I am talking about, I have used this lens with architectural subjects and the barrel/pincushion distortion is very well corrected with DXO.

     

    But then you are busy I'm sure and would not necessarily know or remember all that. Strange, you do recall just enough to give you ammunition to insult.

     

    So bottom line for me is this:

     

    Lens Correct is set unchecked. I'll look from time to time as more corrections show up, and if I find them satisfactory and at least equivalent to DXO, I'll use it. Why not? It fits the workflow so much better. And I'll come back and share my findings. So Lens Correction in ACR won't affect me.

     

    Photomerge using Geometric Correction in Auto is a non-starter. I really like it better for some stitches than Reposition, but Reposition in CS3 is better than Reposition in CS5 (or 4) which is why I would go back to it.

     

    Yes, it is complicated, complex even. What I am doing is simplifying it best I can so I can work at photography, not test and measurement.

     

    Message was edited by: Hudechrome

     
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    Jun 7, 2010 6:59 PM   in reply to mronen

    mronen wrote:

     

    Thanks MadManChan2000 for the clarifications.

     

    You say:  "You do not have to worry about double-correction if you're processing raw files."

     

    Is that because no correction is applied to RAW files, or because ACR will identify that the image has already been corrected?

     

    Moshe

     

    Correct. More specifically, ACR does not bake lens correction adjustments into raw data (in fact ACR does not bake any image adjustments to raw data), so it is not possible for ACR to apply lens corrections twice. I am speaking here of the profile-based capabilities. (Of course, if you do use a profile to remove distortion, for example, and then go to the Manual tab and drag the Distortion slider all the way to the left, the result will have lots of barrel distortion. I'm not considering that case here.)

     
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    Jun 8, 2010 5:52 AM   in reply to mronen

    Ther is no simple answer here. As indicated in another thread, some 

    cameras apply LC to raw data, some do not. Some allow users to adjust 

    this, some do not. Some will indicate in metadata that LC has already 

    been applied, some will not. Hence, it depends. Generally if a camera 

    does apply LC to raw data, ACR does not know about it. This doesn't 

    mean you have to worry about double corrections, though, because the 

    profile may have been made assuming the camera already applied LC to 

    the raw data.

     

    Generally, though, all of this is pretty rare (less than 1%) case.

     

    Eric

     
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    Jun 8, 2010 8:33 AM   in reply to mronen

    But if that 1% applies to you, and the project is architectural the client may become rather cross if you don't catch it! I guess that's why I am such a stickler. I don't want to be blindsided. I once shot a job where the fascia board was not straight but sagged a little. The client blamed the camera, and by default, me and when I pointed out that other views of the building did not show distortion, he relented but then grumbled about why in hell did I even show it to him in the first place? I didn't get much work from them after that.

     

    It's my bad, no matter what, and I agree.

     
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    Jun 8, 2010 12:05 PM   in reply to Hudechrome

    Hudechrome wrote:

     

    But if that 1% applies to you, and the project is architectural the client may become rather cross if you don't catch it! I guess that's why I am such a stickler.

     

    And again, this applies to point and shoot cameras whose lens corrections are done automatically by the camera when shooting JPEG or by Camera Raw when shot in raw.

     

    If you are telling me there are a bunch of architectural shooters out there using point and shoot cameras that will get screwed up by double lens profiling I would expect that to simply not be the case.

     

    In the case of the JPEG shot and brought into Camera Raw, the application of a lens correction above and beyond what is auto done by the camera would require the user to burrow down and force an incorrect profile to be applied. In the case of the raw shot, again, by default the lens corrections have been applied by Camera Raw and again the user would have had to have made a choice to do the wrong thing.

     
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    Jun 8, 2010 2:00 PM   in reply to Jeff Schewe

    I'm not telling YOU anything like that, Jeff.You are telling yourself. Don't put words in my mouth, please.

     

    We are on different pages, technically and philosophically, so far as getting the job done correctly this time and every time. I have spent many years in test and measurement, the result being a workflow steeped in good basic engineering principles, devoid as much as possible of traps. I trust no one to do that for me. With me yes, but not for me, especially if I am the one signing off on it.

     

    "I can do it right or I can do it right now".

     

    "Time, money, quality. Pick any two."

     

    Oh, and if you care to look, my primary focus has shifted from ACR, which I can safely ignore,  to Photomerge. I checked CS4 and the same selection using Auto>Geo correction exits as does CS5, except CS5 appears to add additional Lens Correction info. No thanks. I"ve already done that and as Eric pointed out, PS has no knowledge of third party corrections. I want to be able to use that function without having that correction applied w/o my consent.

     

    I'm starting to sound like a broken record, so for the record:

     

    There are too many uncertainties about Lens Corrections for my comfort and I decline their use in my workflow.

     
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  • Currently Being Moderated
    Jun 8, 2010 10:19 PM   in reply to Hudechrome

    Hudechrome, no question, if that 1% applies to you, you care. I get that.

     

    My suggestion is this: If you have doubts about a specific workflow, then ask and please be specific. Example: "I am shooting with Nikon D700 and various Nikkor lenses like the 14-24 and 24-70. Do I need to worry about camera applying lens corrections to raw data?" Short answer: No.

     

    My only request is this: let's be concrete and not speak too generally here. Lens corrections is a large and complex project. As with many such projects, there are always edge & special cases. For this initial release, we have tried hard to make the common cases easy, the rare ones possible (but maybe harder). That does not mean we've covered everything.

     
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    Jun 9, 2010 12:24 AM   in reply to MadManChan2000

    Hudechrome, no question, if that 1% applies to you, you care. I get that.

    Thank you!

     

    At the moment, only one of the 6 lenses I use is on the list, 70 to 300mm, which is what I tested. I don't see any indication in the D90 manual that lens correction is available, so the short answer applies here and for the foreseeable future. I'll continue to monitor the growth of the lens offerings and try them as they become available. The Enable Lens Corrections is unchecked and set as default.

     

    I'll also be interested in what and how industry standards become set and how the manufacturers relate to them. Sounds like DNG all over again.

     

    I didn't expect to see everything covered, but I did expect that decisions on basics have been established such that some high degree of consistency applies.

     

    So, when I see new optics introduced I use, I will get specific. Till then, I'll basically lurk. And shoot!

     

    Lawrence

     
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  • Currently Being Moderated
    Jun 9, 2010 1:35 AM   in reply to Hudechrome

    Hudechrome wrote:

     

    At the moment, only one of the 6 lenses I use is on the list, 70 to 300mm, which is what I tested. I don't see any indication in the D90 manual that lens correction is available, so the short answer applies here and for the foreseeable future. I'll continue to monitor the growth of the lens offerings and try them as they become available. The Enable Lens Corrections is unchecked and set as default.

    As far as I know, any vignette or lateral CA correction done in the D90 only applies to post-processing (in-camera JPEG or computer-based raw conversion with CaptureNX). I don't know if the D90 does lens distortion correction, but if it did, I suspect this would also be a post-processing add-on, like D-Lighting. As we are discussing Camera Raw, I don't think you need to worry about any of these functions, unless you are using ACR to process JPEGs.

     
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  • Currently Being Moderated
    Jun 9, 2010 11:21 AM   in reply to Yammer

    A quick update on the D90. it does provide CA correction in jpegs but not RAW. My understanding when deciding between D300 and D90 was that the D300 did, the 90 did not. Since it was a jpeg availability and not RAW, it became a moot point in the decision process.

     

    Since jpegs can be opened in ACR, what happens under these circumstances? I see no input for camera model, only manufacturer and lens types.

     
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  • Currently Being Moderated
    Jun 9, 2010 12:33 PM   in reply to Hudechrome

    Hudechrome wrote:

     

    Since jpegs can be opened in ACR, what happens under these circumstances? I see no input for camera model, only manufacturer and lens types.

     

    I don't think it's worth losing any sleep over this. And Eric will be wondering what he got himself into.

     

    If I wanted to process a JPEG with ACR, I'd stick to basic settings, and do any lens correction in 16 bit in Photoshop, if necessary.

     
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    Jun 12, 2010 2:22 PM   in reply to Yammer

    Correct, for the D90, the answer is simple: the camera applies LC to the JPEGs, but not raw. So if you're interested in using ACR to process raw files from your D90 with lens corrections via ACR lens profiles -- no worries, and no double lens corrections.

     
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    Jun 12, 2010 8:12 PM   in reply to MadManChan2000

    OK.

     
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