Between work and trying to think of something to write about now that I finished the Greece series, I realized that there was one feature in the new Lightroom 3.0, which really has made a visible difference in the processed images. All lenses have a degree of distortion. One of the reasons expensive lenses are so, well expensive is that they minimize this distortion. Some lower priced zoom lens get visible vignetting in the corners at certain aperture settings. The corners get darker than they should thanks to the bending of the light. Adobe has developed the capability to mathematically correct the images for Lightroom and for Adobe Camera Raw in Photoshop CS5. As with all LR features, these corrections are completely non-destructive. Here is an example of an image with and without the corrections.
Just select the check box for “Enable Profile Corrections” and if it has a model for that lens, it will apply the correction. They keep adding new profiles and release them with the updates.
The model for each lens from each manufacturer has to be built separately. Here is a link to the current list of supported lenses http://kb2.adobe.com/cps/846/cpsid_84666.html .
The Nikon lens list includes the most popular models.
|Nikon 6-24mm f/2.7-5.9||Nikon|
|Nikon AF DX Fisheye-Nikkor 10.5mm f/2.8G ED||Nikon|
|Nikon AF Fisheye-Nikkor 16mm f/2.8D||Nikon|
|Nikon AF Nikkor 50mm f/1.8D||Nikon|
|Nikon AF-S DX NIKKOR 35mm f/1.8G||Nikon|
|Nikon AF-S DX VR Zoom-Nikkor 18-200mm f/3.5-5.6G IF-ED||Nikon|
|Nikon AF-S DX Zoom-Nikkor 12-24mm f/4G IF-ED||Nikon|
|Nikon AF-S DX Zoom-Nikkor 18-70mm f/3.5-4.5G IF-ED||Nikon|
|Nikon AF-S NIKKOR 14-24mm f/2.8G ED||Nikon|
|Nikon AF-S NIKKOR 24-70mm f/2.8G ED||Nikon|
|Nikon AF-S NIKKOR 70-200mm f/2.8G ED VR II||Nikon|
|Nikon AF-S VR Micro-Nikkor 105mm f/2.8G IF-ED||Nikon|
|Nikon AF-S VR Zoom-Nikkor 70-200mm f/2.8G IF-ED||Nikon|
|Nikon AF-S VR Zoom-Nikkor 70-300mm f/4.5-5.6G IF-ED||Nikon|
Obviously not all of the lenses people use are built yet, so they also offer a utility which allows you to create your own profiles. It can be downloaded from the Adobe Labs at http://labs.adobe.com/technologies/lensprofile_creator/ The instruction are also included. According to the Flickr discussion group it is fairly easy to use.
” The beauty of Adobe's tool is that you need no fancy equipment whatsoever. In fact the only requirements are that you can mount the chart flat (can be as small as 8 1/2"x11") and that you can provide constant illumination (doesn't have to be superhomogenous just constant between shots). Larger charts can be print out for little money using labs like costco's for almost nothing ($9 for a 20x30 nowadays!). Then shoot a minimum of 9 shots of the chart at several focal lengths for a zoom lens at a single aperture (11) in manual mode which you can do handheld without a loss of quality of the profile, it really doesn't matter. Then load those shots into the lens profile creator app and let it crank away. I've done this for a few of my unlisted lenses and the profiles work excellent. I've also submitted these profiles to Adobe, but unfortunately, the Lightroom engineers did not yet build in the feature you have access to in the lens correction filter in Photoshop CS5 where you can download the user submitted profiles for a lot of lenses from Adobe. This should be fixed in an upcoming update to Lightroom. For now, you either have to use CS5 to download profiles or profile the lenses yourself, which is easy. Adobe really did a great job on this tool to make it usable for folks without any special equipment. “ http://www.flickr.com/groups/adobe_lightroom/discuss/72157624239647554/
Although it exists in Photoshop CS5, there is not yet a way to share or retrieve profiles others have created online. It is coming, at least according to Adobe.