More Reading: Looking at Lens Corrections
Showing posts with label Lens Profiles. Show all posts
Showing posts with label Lens Profiles. Show all posts
Monday, 27 January 2025
Thursday, 3 March 2016
Looking into Lens Corrections
From time to time, people ask why Olympus or Panasonic lenses are not listed in the Lens Profiles of Lightroom. The confusion is both from us for not seeing the clues and from Adobe for poor user interface / communication of the message to the end user.
What do people mean by Lens Corrections?
Lenses are physical designs and have optical imperfections in creating the image. Designers choose to reduce these imperfections to the minimum but that impacts lens bulk, size, number of elements and cost. Or thinking the other way, lens designers in the digital world, can purposely design imperfect lenses and rely on the camera firmware or computer software to correct them.
The imperfections cover:
- colour fringing (sometimes called Chromatic Aberration)
- optical vignetting falloff (darkening of the image corners)
- curvilinear distortion (straight lines becoming bowed inwards (pincushion) or outwards (barrelling)
Where are the correction parameters stored?
Correction metadata can be stored
- single Lens Correction Profile in separate files one file per lens. Separate files are useful when a user voluntarily carries out the measurements and submits them to the software vendor (e.g. Adobe).
- stored as an "internal" integrated database supplied with the software program
- stored in lens firmware which is then copied by camera body and saved as metadata in the raw file
- stored in lens firmware which is then applied by camera body to the camera JPEG. In which case the SOOC (Straight Out Of The Camera) JPEG does not separately store the parameters, the JPEG is considered the corrected and finished image.
What do software user interfaces look like when they acknowledge the lens identity?
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| Adobe Lightroom Lens Correction panel in the Develop Module |
Above, you see the Adobe Lightroom Lens Correction panel in the Develop Module. This is what the panel looks like when the lens is recognised by Lightroom. You don't have to take any action. If you click on the Information (i) icon, you will see a dialog stating what the lens model is.
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| Adobe Lightroom Lens Correction panel in the Develop Module |
Above is the Lightroom Lens Correction panel if you explicitly click on the checkbox "Enable Profile Corrections" - presumably, if the lens is already in the internal database, the information it already knows is ignored and you can nominate the individual Lens Profile files that Adobe has supplied or you have created yourself or that you have downloaded using the Adobe Lens Profile Downloader.
Also See: Lens Profile Corrections
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| Adobe Camera Raw Lens Correction Panel |
Similar to Adobe Lightroom's panel design, this is the Adobe Camera Raw Lens Correction panel. Note that this panel is more informative - you do not have to click one more time to display the identification / name of the lens
If you get an .lcp file from a third party, to allow Lightroom and Adobe Camera Raw access to it, put the .lcp file in
C:\Users\yourusername\AppData\Roaming\Adobe\CameraRaw\LensProfiles\1.0\Downloaded
If you get an .lcp file from a third party, to allow Lightroom and Adobe Camera Raw access to it, put the .lcp file in
C:\Users\yourusername\AppData\Roaming\Adobe\CameraRaw\LensProfiles\1.0\Downloaded
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| DxO ViewPoint 2 Distortion Correction Panel |
Above is the DxO ViewPoint 2 Distortion Correction Panel. Presumably the DxO Optics user interface will be similar. Note that DxO not only identifies the lens, it also identifies which body it is fitted on. This extra information might be used in their corrections.
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| Corel Aftershot Pro 2 Lens Correction Panel |
Above is the Corel Aftershot Pro 2 Lens Correction Panel. It too identifies the camera body and the lens. Clicking "Enable Correction" does not appear to disable Correction, does it enable Correction and not ticking it ignore Correction? Chromatic Aberration and Vignette Correction are not automatically ticked when you tick Enable Correction.
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| Raw Therapee Lens Correction Panel |
Raw Therapee is a free raw editor. I don't see information about whether it has or knows how to use an internal database. But if you choose to use a Lens Correction Profile, the resulting file selection dialog will refer to Adobe's nest of folders on your computer.
More reading:
More reading:
- Photography Life article on Lens Corrections in Lightroom
- Julieann Kost's article
- Adobe intro video
- Adobe Help on cameras with built-in lens support (MFT)
- Adobe document on Lens Correction Profiles and folder locations, Mac and Windows
- Creating your own LCP
Monday, 25 August 2014
Quick Notes on Olympus RAW and Lens Profiles in Lightroom
Here's a verbatim copy of a post to a FB group when we were discussing Olympus Lens Profiles and Lightroom. I'll update this when I get feedback, corrections and so on.
The Adobe Lens Profile issue is potentially confusing. Let me note the points and hopefully people can add / discuss.
1. ORF - the Olympus RAW or any camera model raw needs to be understood by the raw processing program. New camera models are released every few months, the third party companies like Adobe have to scramble to get their programs updated. Sometimes, the sensor is the same but the EXIF signature is different e.g. my E-PM2 file is similar to the OMD E-M5 but some old programs refuse to load the E-PM2 raw. If I use an EXIF editor and change the camera name, presto, the old program reads the file.
2. Adobe has a habit of deciding that a certain version of LR or ACR will no longer be supported by them - they make money by selling new versions - they don't get income by supporting their old programs for new cameras. Adobe is not the only company that does this. The Adobe blog will have announcements on which version of LR or PS a certain new model starts getting supported.
3. The Lens profile is not related to the sensor data of raw - it describes vignetting, fringing, curvilinear distortion. Since last year, there have been additional lens info being stored - e.g. the lens bokeh / out of focus info - Panasonic uses this for super fast focussing in the GH4. Olympus uses it for when rendering the JPEG in the camera or Olympus viewer. If the program can read the raw, it can produce an image on screen and for JPEG, it just doesn't automatically correct for the lens behaviour.
4. Olympus from Four Thirds lenses era (1990s) stores this data in lens firmware. Panasonic does similar. That PhotoHelpdesk article claims that Adobe LR reads that and uses MFT lens data from the raw file. I don't know the truth of that claim.
5. For other brands of camera and lenses, or for manual focus lenses, Adobe or users can run the Adobe Lens Profile Creator program and produce separate lens profile files - many of the other brands lenses are automatically installed with LR - hence you can see them in the screenshot of the menu above. If you download the Lens Profile Creator software, you can also run a menu item that grabs Olympus Four Thirds DSLR lens profile files from Adobe and installs them into the LR subfolder.
6. In LR 5.6, I have tried "Enable default lens correction" on a raw but I don't see the image wriggle if the lens name is not identified. If the lens name is identified, I see the image wriggle once - I think this means the lens correction has taken action.
7. This lens correction data is typically in raw metadata because we assume that the file is clean from the camera. It is not stored in JPEG because the JPEG is normally "baked" or "cooked" already. Certainly software can correct the JPEG but the industry hasn't catered for that aspect.
8. If you shoot SOOC JPEG in an Olympus body, it is corrected for vignetting and curvilinear distortion. The Olympus RAW is not corrected but it contains the data. If you shoot SOOC JPEG of a Panasonic lens on a Panasonic body, you also get correction for fringing (CA).
The Adobe Lens Profile issue is potentially confusing. Let me note the points and hopefully people can add / discuss.
1. ORF - the Olympus RAW or any camera model raw needs to be understood by the raw processing program. New camera models are released every few months, the third party companies like Adobe have to scramble to get their programs updated. Sometimes, the sensor is the same but the EXIF signature is different e.g. my E-PM2 file is similar to the OMD E-M5 but some old programs refuse to load the E-PM2 raw. If I use an EXIF editor and change the camera name, presto, the old program reads the file.
2. Adobe has a habit of deciding that a certain version of LR or ACR will no longer be supported by them - they make money by selling new versions - they don't get income by supporting their old programs for new cameras. Adobe is not the only company that does this. The Adobe blog will have announcements on which version of LR or PS a certain new model starts getting supported.
3. The Lens profile is not related to the sensor data of raw - it describes vignetting, fringing, curvilinear distortion. Since last year, there have been additional lens info being stored - e.g. the lens bokeh / out of focus info - Panasonic uses this for super fast focussing in the GH4. Olympus uses it for when rendering the JPEG in the camera or Olympus viewer. If the program can read the raw, it can produce an image on screen and for JPEG, it just doesn't automatically correct for the lens behaviour.
4. Olympus from Four Thirds lenses era (1990s) stores this data in lens firmware. Panasonic does similar. That PhotoHelpdesk article claims that Adobe LR reads that and uses MFT lens data from the raw file. I don't know the truth of that claim.
5. For other brands of camera and lenses, or for manual focus lenses, Adobe or users can run the Adobe Lens Profile Creator program and produce separate lens profile files - many of the other brands lenses are automatically installed with LR - hence you can see them in the screenshot of the menu above. If you download the Lens Profile Creator software, you can also run a menu item that grabs Olympus Four Thirds DSLR lens profile files from Adobe and installs them into the LR subfolder.
6. In LR 5.6, I have tried "Enable default lens correction" on a raw but I don't see the image wriggle if the lens name is not identified. If the lens name is identified, I see the image wriggle once - I think this means the lens correction has taken action.
7. This lens correction data is typically in raw metadata because we assume that the file is clean from the camera. It is not stored in JPEG because the JPEG is normally "baked" or "cooked" already. Certainly software can correct the JPEG but the industry hasn't catered for that aspect.
8. If you shoot SOOC JPEG in an Olympus body, it is corrected for vignetting and curvilinear distortion. The Olympus RAW is not corrected but it contains the data. If you shoot SOOC JPEG of a Panasonic lens on a Panasonic body, you also get correction for fringing (CA).
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