The Lightroom team has announced the availability of the release candidate for Lightroom 5.3.  Release candidates are made available before official releases in order to get broader community testing and feedback. This release contain bug fixes, new camera support, new lens profiles and a few new Develop shortcuts.  My general recommendation regarding release candidates is for most people to wait for the official release, unless you have one of the new cameras or need a new lens profile, or unless the bugs that have been fixed are affecting you. With 5.3, there are some important bug fixes, so do review the list below.

This Lightroom 5.3 Release Candidate is a free (early) update to Lightroom 5. It can be downloaded from labs.adobe.com. (Once the file downloads, double-click on it to install the update.)

Lightroom 5.3 RC Develop Module Tweaks:

For those of you who use Auto White Balance, which analyzes your image data to determine a “best guess” white balance value, the following new shortcuts will come in handy:

• Shift+double-clicking on the Temp or Tint slider label  sets each to its Auto White Balance value.
• Shift+double-clicking on the White Balance label sets the Temp and Tint sliders to their Auto White Balance settings and the WB menu to “Auto”. (This is different from the existing behavior of Opt/Alt-clicking or double-clicking on the WB label, which resets the Temp and Tint sliders to their “As Shot” values, and the WB menu to “As Shot”.)

Similarly, if you want Lightroom to set Whites and Blacks automatically to maximize the range of tones from white to black, the following shortcut will be useful. (I still recommend setting Whites and Blacks last, as per this article.)

•  Shift+double-clicking to set the auto values for the Whites and Blacks sliders will now take into account current non-default settings, as well as other factors such as the current crop.

Lightroom 5.3 RC New Camera Support:

* Denotes preliminary support.

Lightroom 5.3 RC Bug Fixes:

• Issues when upgrading catalog from previous versions of Lightroom.
• Incorrect photos are displayed after switching away from a Publish Collection.
• Catalog optimization did not finish, and was not optimizing the catalog
• Feather of clone spots is set to 0 after upgrading catalog to Lightroom 5.
• Auto White Balance settings are not saved to Snapshots.
• Sony 18-55mm lens is detected as the Hasselblad 18-55mm lens for lens correction.
• Increased Update Spot Removal history steps when in Before and After view.
• Slideshows start playing automatically even when the Manual Slideshow option is enabled.
• Video playback stops when dragging on the scrubber.
• Errors when publishing photos to Flickr through the Publish Service.
• Option + drag on Edit Pin behavior is functioning incorrectly.
• Black border appears around the exported slideshow video.
• Catalog containing images processed with PV2003 were adding a post-crop vignette when catalog upgraded to Lightroom 5.
• Pressing the “Reset” button while holding down the Shift key caused Lightroom to exit abruptly.
• Output Sharpening and Noise Reduction were not applied to exported images that were resized to less than 1/3 of the original image size.
• Incorrect photo was selected when trying to select a photo in segmented grid in Publish Services.
• The Esc key did not exit the slideshow after right clicking screen with mouse during slideshow playing.
• Import dialog remained blank for folders that contain PNG files with XMP sidecars.
• Metadata panel displayed incorrect information after modifying published photo. Please note that this only occurred when metadata was changed after the photo was published.

Lightroom 5.3 RC New Lens Profiles:

• Apple iPhone 5S
• Canon EOS M Canon EF-M 11-22mm f/4-5.6 IS STM
• Nikon 1 NIKKOR AW 11-27.5mm f/3.5-5.6
• Nikon 1 NIKKOR AW 10mm f/2.8
• Nikon AF-S NIKKOR 58mm f/1.4G
• Nikon Sigma 18-35mm F1.8 DC HSM A013
• Sigma Sigma 18-35mm F1.8 DC HSM A013
• Sony E 20mm F2.8
• Sony FE 28-70mm F3.5-5.6 OSS