Adobe tonight announced the  availability of Lightroom 4.2, a free update for Lightroom 4 owners. This release does not add new features, but it does address some performance issues with Lightroom 4.1, and also adds support for several new cameras and lenses, tethering for more cameras, and several bug fixes.

If you open Lightroom 4 and it does not prompt you automatically to download the update, go to Help>Check for Updates. Once the update downloads, double-click on the file to launch the installation wizard. If it is not yet available, you can also click here to download it directly from adobe.com.

If you are also working with Photoshop CS6, be sure to also update Camera Raw to 7.2, also released tonight with the same updates.  In Bridge or Photoshop, go to Help>Check for Updates.

Performance Issues Addressed

Hopefully those of you experiencing performance issues with Lightroom 4.1 will benefit from these improvements. There have been changes made to the way views are updated in the Develop module. This should result in improved performance when:

• Stepping through edited images in Develop with the filmstrip showing.
• Doing Develop work with Loupe, Compare, or Survey mode displayed on your secondary monitor, or with the filmstrip showing. (Sliders should be more responsive).
• Switching back to Library immediately after editing in Develop.

New Cameras Supported:

Canon EOS 650D / Rebel T4i, Canon EOS M, Fujifilm XF1, Fujifilm X-E1, Fuji FinePix F800EXR, Leaf Credo 40, Leaf Credo 60, Leica S, Leica D-LUX 6, Leica V-LUX 4, Nikon Coolpix P7700, Nikon 1 J2, Panasonic DMC-G5, Panasonic DMC-LX7, Panasonic DMC-FZ200, Pentax K-30, Samsung EX2F, Sony Alpha NEX-5R, Sony Alpha NEX-6,   Sony Alpha SLT-A99V, Sony DSC-RX10.

Preliminary support has also been added for the Nikon D600 (with a Beta profile in the Camera Calibration panel.)

Tether Support Added:

Nikon: D4, D800, D800e
Canon: EOS Kiss X5, EOS Kiss REBEL T3i, EOS 600D, EOS Kiss X50, EOS REBEL T3, EOS 1100D, EOS 5D Mark III, EOS 1D X

Bug Fixes:

• Stacked photos were hidden in both the Grid view and Filmstrip. This occured when photos get unstacked as a result of enabling auto-stacking.
• Folder stacks with virtual copies were unstacked when moving to another folder.
• When scrolling through the filmstrip (at somewhat fast rate), occasionally a “gray” image was displayed for an instant and then replaced by the correct image preview.
• The Navigator Panel in Map did not pan correctly.
• Parents and synonyms of “do not export” keywords also did not export
• Occasionally unable to publish videos to Facebook
• Audio did not play in video files after creating a slideshow that contains music (Win 7 only)
• Image select arrow on keyword list didn’t display when keyword list contained a large number of keywords
• Unable to edit Lightroom photos as JPEGs in Photoshop Elements
• Carriage Return in either the Title or Caption field invalidated a Flickr upload
• Tether capture bar disappeared after deleting photo (Win only)
• Back Cover of Book layout had Horizontal text on spine rather than Vertical
• Sharpening was not applied to books that were exported as JPEG files
• Double-byte characters were not exported to Books saved as PDF files
• Unable to type accented character in book module in LR4
• Luminance Noise slider was unresponsive when Clarity is greater than 0.
• Develop keyboard shortcuts (+ and – keys) no longer worked in older process versions such as PV 2010

For a list of new lens profiles, see the official announcement.