Friday, June 4, 2010

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Camera Raw v6.1 Lens Corrections

If you have bought Adobe Photoshop CS5, you should ensure you also have the latest update of Adobe Camera Raw (ACR).  If you haven't upgraded to CS5 yet, Beau Photo has the upgrades in stock!

At first glance, ACR 6.1 might not look all that much different than 6.0 or, for that matter, the 5.x versions, but trust me, it is! First off, v6.0 has brought a whole new level of image quality, with massively improved rendering of fine detail, mainly due to its new demosaic, sharpening and noise reduction algorithms. Version 6.1 ushers in something that is truly huge though: automated lens corrections for chromatic aberration, vignetting and even distortion. This is the part of the new ACR window I want to draw your attention to:

When you activate the "Enable Lens Profile Corrections" checkbox, ACR will examine the metadata of your shot to see which lens you used, look it up in its database, check what focal length (if it was a zoom) and f-stop you shot at, then activate the corrections for you... all automatically! At the moment, only a limited number of lenses have been profiled by Adobe, but they will surely be working on more.  Here is the list of Canon lenses that Adobe currently has profiled:

Not a bad list for the first version! The control at the bottom right of the main ACR window, "Correction Amount", allows you to dial in more or less effect of the automatic corrections.  Lets say you'd like to keep some of the vignetting when you shot your EF 35mm f/1.4L wide open, well just slide the vignetting correction slider down to less than 100%, to bring back some of the original vignetting in the shot.  Lets say your old, beat up EF 16-35mm f/2.8L is behaving a little worse than average and is giving some extra chromatic aberration... well just crank up the "Chromatic Aberration" slider beyond 100% for a little bit of extra correction, over and above the defaults.

If your lens is not yet listed, you can either click on the "Manual" tab for full manual control over these settings (like older versions of ACR but with the added bonus of a distortion slider), or if you are very ambitious, you could download Adobe's Lens Profile Creator from Adobe Labs and roll your very own customized set of corrections!

Finally, these auto corrections do not seem to be enabled by default, if if you open an image taken with a supported lens, so in order to automate this, you should open a new, never-opened image (or just ensure that you've chosen "Camera Raw Defaults" from the settings menu, go to the Lens Corrections page and click the "Enable Lens Profile Corrections" checkbox and ensure Setup: is at Auto, then go back to the settings menu and choose "Save New Camera Raw Defaults".  The next time you open an image with a supported lens, ACR should automatically enable those corrections! Lastly, if you have ACR configured to make Camera Raw Defaults specific to a certain ISO, you will unfortunately need to do this step for every ISO you normally shoot at.

For those Nikon shooters reading this, here is the list of Nikon lenses supported with ACR v6.1.  I wonder if there are simply more Canon shooters working at (or with) Adobe, or if fewer Nikon lenses actually need correction?!

Adobe Lightroom v3, which could be released as soon as next week, will likely also support these auto lens profile corrections.  Finally, the automatic lens corrections that Hasselblad digital back users have enjoyed for years already, are coming to DSLR users via Photoshop and Lightroom.  Cool!


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